Table of Content

20 October 2011, Volume 20 Issue 5

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Belowground biomass and its relationship to environmental factors of natural grassland on the northern slopes of the Qilian Mountains

HUANG De-qing, YU Lan, ZHANG Yao-sheng, ZHAO Xin-quan

2011, 20(5):  1-10. 

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The belowground biomass and its relationships with environmental factors of natural grassland: alpine steppe, mountain meadow, mountain meadow steppe, mountain steppe and mountain-desert grassland of the northern slopes of the Qilian mountains were investigated. 1) The belowground biomasses of five kinds of grassland differed significantly (P＜0.05) except for mountain steppe, mountain meadow steppe, and alpine steppe. The belowground biomass reduced with soil depth in an exponential manner and with a “T” shape distribution. 2) Seasonal change of the belowground biomass was of a “W” type in alpine steppe and of a “N” type in other grasslands, and decreased with soil depth. 3) Below ground net productivity of mountain meadow was the highest (546.84 g/m²), and was followed by mountain meadow steppe (410.76 g/m²), mountain steppe (358.12 g/m²), alpine steppe (301.33 g/m²) and mountain-desert grassland (81.68 g/m²). Turnover value of the belowground biomass was beyond 45%. 4) There were negative correlations between the belowground biomasses of five kinds of grassland and the hydrothermal factor, though the correlations were not significant except for mountain-desert grassland. But the correlations (positive or negative) between the belowground biomasses of five kinds of grassland and the hydrothermal factor were highly significant in the 7-8 months with better hydrothermal conditions. In other months, the correlations between the belowground biomasses of different grasslands and environmental factors was very varied.

Characters and dynamics of modular biomass and its allocation ratio in five cultivars of elephant grass

LI You-han, XIE Zhao-liang, XIE Xin-ming

2011, 20(5):  11-18. 

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Elephant grass (Pennisetum purpureum), a valuable forage in south China, is a typical clonal plant. Modular theory was used to analyze the characteristics and dynamics of modular biomass and its allocation ratio in five elephant grass cultivars (MT-1, Mott, Huanan, N51 and Guimu No.1) from 2007 to 2009, with six harvests. The allocation ratios of culm and leaf blade were the highest and second highest respectively of the modules which contributed to the accumulation of photosynthate in the vegetative growth period. From vegetative growth to reproductive growth, the leaf biomass diminished but dead leaf biomass and culm biomass increased. Similarly, the biomass of three internodes of the culm base and its allocation ratio reduced while the culm biomass and its allocation ratio increased.

Vegetative reproduction characteristics of Leymus chinensis populations in Tumuji National Nature Reserve, Inner Mongolia

LI Hai-yan, LI Jian-dong, XU Zhen-guo, ZHOU Jing-ying, ZHANG Jian-feng

2011, 20(5):  19-25. 

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Quantitative features of vegetative reproduction of grey-green and yellow-green Leymus chinensis on meadow and meadow steppe were studied in Tumuji National Nature Reserve, Inner Mongolia. In two vegetation types, the number and biomass of two ecotype L. chinensis tillers consisted of four age classes of which the 4-year tillers were the fewest. The tillers were stable or expansive age structures. The 2-year rhizomes were dominant, and were stable age structures. The productivity per tiller of 1-year tillers of the two ecotypes was the highest and the productivity gradually decreased with increasing age classes. The productivity per tiller on meadow steppe was significantly higher than those of meadow grey-green and yellow-green ecotypes. The 1-year or 2-year rhizome productivity of the two ecotypes was the highest. In temperate herbaceous communities, increased or stable age structures, vigorous matter production and storage of both young tillers and rhizomes were essential reasons for sustaining flourishing perennial clonal plants.

Comprehensive evaluation of drought resistance of Reaumuria soongorica from four geographical populations

CHONG Pei-fang, SU Shi-ping, LI Yi

2011, 20(5):  26-33. 

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Reaumuria soongorica from four geographical populations (Lanzhou Jiuzhoutai: LZJ, Wuwei Minqin: WWM, Zhangye Linze: ZYL and Jiuquan Jinta: JQJ) were studied in a natural environment. Eighteen physiological indexes of R. soongorica, including photosynthetic rate (Pn), transpiration rate (Tr), water use efficiency (WUE), chlorophyll, soluble sugar (SS), proline (Pro), malondialdehyde (MDA), superoxide dismutase (SOD), peroxidase (POD) were measured. Subordinate function and grey correlative analysis of drought-resistance and its relationship with drought-resistance indexes of R. soongorica were used for a quantitative evaluation of comprehensive drought resistance. The drought resistance capability of R. soongorica from four geographical populations was in the order WWM＞JQJ＞ZYL＞LZJ. There was a general tendency in lower water conditions for more capable drought resistance with the result that plants adapted to environmental condition through adjusting their physiology. Eighteen drought resistant indexes were restricted and relied on each other in the drought resistance mechanisms of the plant, and they adjusted the inner drought resistance mechanisms comprehensively. The three main mechanisms (increasing WUE through declining Tr, the xanthophyl cycle-dependent thermal energy dissipation, and osmoregulation mechanisms) mainly rely on Pro and occupy an important place in the drought resistance mechanisms of R. soongorica.

Assessment of interspecies drought resistance of Elytrigia at the seedling stage

MENG Lin, YANG Hong-xin, MAO Pei-chun, GAO Hong-wen

2011, 20(5):  34-41. 

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The drought resistance of 10 species of Elytrigia, collected from six countries, was identified and evaluated using simulated drought stress and rewatering in a green house at the seedling stage. The relative water content of leaves (RWC), relative electrical conductivity rate (REC), free proline accumulation (Pro), contents of malondialdehyde (MDA) and the soluble sugar content (SSC) were measured at 0 (CK), 7, 14, 21, 28, and 35 days of drought stress and 7 days after rewatering. Their average survival rates (ASR) after 35 days of drought stress followed by the rewatering were calculated. The three drought resistant classes: high drought resistance (ET001, EPU02, EJ003 and EH001), medium drought resistance (ES001, EE013 and EC002) and weak drought resistance (ER037, EL001 and EI022) were classified using the above 5 physiological indexes by the Euclidean distance clustering method.

A study on the physiological and biochemical characters of different Stipa grandis geographical populations

WANG Jin-long, ZHAO Nian-xi, XU Hua, GAO Yu-bao

2011, 20(5):  42-48. 

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To analysis the adaptability of Stipa grandis to environmental conditions, five typical regions were selected in the Xilingol steppe. There were significant differences between populations for these characters except Chl a/b, but the frequencies of these traits along environmental variations were not consistent when tested by Pearson correlation analysis. Further analyses indicated: 1) The chlorophyll contents and MDA content were sensitive traits, and reflected the differences of environmental conditions. The chlorophyll contents reflected the status of S. grandis, and the MDA content reflected the drought status of their habitats. 2) This was related to the response of protective enzymes to stress conditions and the growth status of S. grandis plants. 3) Osmotic adjustment substance contents could be complementary within a population. The study provides scientific data and proofs to understand the adaptive mechanisms and strategies of S. grandis.

Effects of different saline-alkali grassland on the photosynthetic physiological characteristics of Elymus dahuricus

DU Li-xia, DONG Kuan-hu, YANG Gui-ying, CHEN Li-kun, XIA Fang-shan, DONG Qiu-li

2011, 20(5):  49-56. 

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The photosynthetic characteristics (using the CI-340 photosynthesis mensurate system) and other physiological indexes of Elymus dahuricus under different saline-alkaline grassland conditions were determined at different growth stages. With an increase of saline-alkaline concentration, the net photosynthetic rate, transpiration rate, stomatic conductance and intercellular CO₂ concentration decreased. Net photosynthetic rate at light (L) and moderate (M) salinity was the largest in July, but the largest net photosynthesis at high (H) salinity was in August. At different months and different saline-alkaline grassland conditions, net photosynthesis was affected by both stomatal limitations and non-stomatal limitations. The content of soluble sugar, MDA and Pro all increased with increased saline-alkaline conditions. MDA content was largest at the seedling stage, but it reduced with the growth of E. dahuricus. The increase of Pro and soluble sugars of E. dahuricus at the seedling and heading stages can reduce seedling damage from salt stress.

Effects of Eucalyptus grandis leaf litter on growth and resistance physiology of Elymus sibiricus in the initial decomposition process of litter in soil

MI Xiao-hua, ZENG Fan-ming, GONG Ping

2011, 20(5):  57-65. 

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The allelopathic effects of leaf litter (in the initial decomposition process of litter in soil) of Eucalyptus grandis on growth and resistance physiology of Elymus sibiricus was studied in a pot experiment. Each pot contained 8 kg soil mixed with 0, 25, 50, 100, or 150 g leaf litter. E. sibiricus was sown in September and height, biomass and several indices of resistance physiology were tested at 30, 40, 50, and 90 d after sowing. 1) Height and biomass of E. sibiricus were significantly inhibited after 90 d. 2) The activities of SOD and CAT in leaves of E. sibiricus increased in conditions of low litter content and short decomposition times but were inhibited with higher-contents of litter or longer treatment times. POD was significantly inhibited by different treatments after 90 days. 3) The MDA content rose with the increasing litter content at 50 d, but had decreased in all treatments by 90 d. 4) The soluble carbohydrate content increased considerably, whereas that of soluble protein had considerably reduced by 90 d. 5) The effects of leaf litter decomposition in soil was high at first but then weakened. Faster and stronger allelopathic effects were observed in treatments with higher litter content than those with lower ones. The compound effect of the 150 g treatment was the strongest, while that of 50-100 g treatments were weaker, and the 25 g treatment was the weakest. On the whole, the leaf litter of E. grandis had a strong allelopathic effect on E. sibiricus in the initial decomposition process of litter in soil.

Effect of planting density on productivity and photosynthetic characteristics of Chamaecrista rotundifolia

ZHAN Jie, LUO Xu-hui, SU Xiao-zhen, YING Zhao-yang, Huang Yi-bin

2011, 20(5):  66-71. 

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To understand responses of Chamaecrista rotundifolia to planting density, the effect of five planting densities (5, 10, 20, 30, 40, 50 plants/m²) on yield, economic characteristics, crude protein and photosynthetic characteristics of C. rotundifolia were studied. There was an initial increase then a decreasing trend with increasing plant density. Yield of fodder reached a peak value at a planting density of 40 plants/m², and yield of hay reached a peak value at 30 plants/m². Crude protein contents of C. rotundifolia were distributed more in leaves than in stems. Crude protein contents initially increased and then decreased with increasing planting density, and reached the peak value at a density of 30 plants/m². The net photosynthetic rate of C. rotundifolia at different planting densities was due to non-stomatal limitation. Synthesize evaluation showed that a planting density of 30 plants/m² gave the highest hay yield of 3 454.83 kg/hm² by C. rotundifolia, and the crude protein production reached 625.83 kg/hm².

Effects of Neotyphodium endophytes on seed germination of three grass species under different pH conditions

PENG Qing-qing, LI Chun-jie, SONG Mei-ling, LIANG Ying, NAN Zhi-biao

2011, 20(5):  72-78. 

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Neotyphodium endophytes may improve host grass competitive abilities by increasing seed germination success and enhancing host plant growth under water stress, salt and other environmental stress conditions. To find if there were differences in germination between Neotyphodium endophyte infected (E+) and uninfected (E-) plants of three grass species (Achnatherum inebrians, Festuca sinensis and Hordeum brevisubulatum), eight pH levels (pH 4-11) were used. The results indicated that the germination energy of E+ A. inebrians seed were much higher than those of E- seed at pH 6-11 (P<0.05); the germination rate was significantly higher at pH 4-5; the shoot and radical growth of E+ were higher than those of E-, especially at pH 7-11 (P<0.05); and there was much higher dry weight at pH 4-7. The percentage of abnormal germination of E+ seed at pH 4 and at pH 11 was significantly (P<0.05) lower than that of E- seed. Similarly, E+ F. sinensis seed performed much better than E- seed in germination rate, germination energy, radical growth, shoot growth and dry weight. There were significant differences in germination energy at pH 6-10 (P<0.05), germination rate at pH 4 and pH 8-11 (P<0.05), shoot growth at pH 4-11 (P<0.05), radical growth at pH 10 (P<0.05), and the dry weight of E+ seedlings was significantly greater at pH 4-6 (P<0.05). The percentage of abnormal germination was highest at pH 11 (P<0.05). Compared with E- H. brevisubulatum, E+ seed had greater germination energy at pH 4-11 (P<0.05); the shoot and radical growth were significantly greater than those of E- seedlings at pH 9-11 and pH 8-11 (P<0.05) as was the dry weight at pH 4-11 (P<0.05). The percentage of abnormal germination of E+ seed was significantly less than that of E- seed at pH 4. Overall, the optimal pH value for A. inebrians was 6-9; for F. sinensis was 6-7, and for H. brevisubulatum was 7-9.

Effects of bio-organic fertilizer on neutral aroma component content in flue-cured tobacco in east of Gansu Province and its mechanisms

LIU Xing, QIU Hui-zhen, ZHANG Wen-ming, LI Ya-juan, TENG Gui-xiang, JIA Huan-huan

2011, 20(5):  79-86. 

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Low content of neutral aroma component (NAC), lack of aroma and flavor and the decline in commodity characteristics caused by long-time continuous mono-cropping and irrational fertilization have been the serious problems in flue-cured tobacco production in east of Gansu Province. A field experiment was carried out in Zhengning County in Gansu Province in 2009 to study the effects of bio-organic fertilizer (BIO) application on NAC content in flue-cured tobacco and its mechanisms. BIO significantly increased the total content of NAC in tobacco leaves by 26.79%-134.33% compared with CK. The total content of NAC at different position of tobacco leaves had dramatically different reaction to BIO, namely, the biggest increase was observed in the upper leaves, and the total content of NAC in upper leaves, middle leaves and bottom leaves were increased by 134.33%, 81.03% and 26.79% respectively compared with CK. BIO application also changed the orders of the total content of NAC in tobacco leaves at different positions, the order of upper leaves＞bottom leaves＞middle leaves in CK treatment, were turned into upper leaves＞middle leaves＞bottom leaves in BIO treatment, which is favorable to the output value of tobacco production. The main NAC in tobacco leaves in Zhengning is neophytadiene, accounting for 79.67%-89.43% of the total amount. The neophytadiene content in upper, middle and bottom leaves of BIO treatment were increased significantly by 157.33%, 88.15% and 31.17% respectively compared with CK. BIO improved the nitrogen absorption by tobacco, which not only increased the chlorophyll content in tobacco leaves, the precursor of neophytadiene, but postponed the summit of chlorophyll content by about 15 days as well which could extend the mature period. Activities of invertase and nitrate reductase at round top stage in BIO treatment were increased by 30.02% and 13.42% compared with CK, which contributed to the dry matter accumulation, nitrogen uptake, as well as to the synthesis of NAC and chlorophyll.

Studies on optimal temperature and time to treat corn stalk by Pleurotus ostreatus

LIU Min, LI Jie, LIU Tan, JING Yi

2011, 20(5):  87-92. 

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The contents in the rumen of fibrous matters, enzymatic activity, and nutrient degradability of corn stalk treated by Pleurotus ostreatus was studied at 16, 20, and 24℃ to find the optimal range of treatment temperature and time to achieve a greatest nutritional value of corn stalk. P. ostreatus fermentation reduced the contents of cellulose, hemicellulose, and lignin in stalks treated at the three temperatures. Following treatment of corn straw with P. ostreatus, fibrous matter was degraded slower (P<0.05) and the activity of fibrolysis enzymes (P<0.01) and dry matter degradability were reduced (P<0.05) in the rumen at 16℃ compared with treatment at 20 and 24℃ but were not significantly different between the temperatures. Dry matter degradability in the rumen of stalks treated at 20 and 24℃ increased with treatment time until 21 days of fermentation, and then remained constant. The optimal conditions to treat corn straw with P. ostreatus to achieve a greater nutritional value for ruminant animals is between 20 to 24℃ for 21 to 30 days or for 30 days at a minimum of 16℃.

Effects of excessive application of nitrogen fertilizer on leaf color, key enzymes activities of nitrogen metabolism and chloroplast ultrastructure of a chimera Hosta ‘Gold Standard’

ZHANG Jin-zheng, LIU Yue-lu, LI Xiao-dong, LIU Hong-zhang, SUN Guo-feng, HE Qing

2011, 20(5):  93-101. 

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Leaf colors, key enzymes of nitrogen metabolism, and chloroplast ultrastructure were studied in excessive application of nitrogen fertilizer cultivation on chimera Hosta ‘Gold standard’. The results showed that: chlorophyll content significantly increased or decreased in yellow or green leaf area of the chimera in the 2 g/kg of urea fertilizer treatment respectively, and leaf of chimera completely turned green within 28 d. Total N content, activities of nitrate reductase (NR) and glutamate dehydrogenase (GDH) of chimera leaf reached to their highest level after 7 days treatment; activities of glutamine synthetase (GS) reached to their highest level after 14 days treatment, and the changing trends of glutamate synthetase (GOGAT) activities was similar to chlorophyll content on chimera leaf. The develepoment of chloroplast ultrastructure, which lacks normal grana stacking, and contains large number of vacuoles was severely inhibited in the yellow leaf area of the chemera. After 28 d fertilization treatments, normal thylakoid lamellar structure was formed in chloroplast of yellow leaf area, which was similar to the chloroplast structure of the green leaf area and leaf of non-chimera Hosta.

Effects of chlortetracycline and 4-epi-chlortetracycline stress on seedling growth, antioxidant enzyme activities and accumulation in pakchoi

WEI Rui-cheng, PEI Yan, ZHENG Xiao-li, ZHU Xu-bo, CHEN Ming, WANG Ran

2011, 20(5):  102-110. 

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The effects of different concentrations of chlortetracycline (CTC) and 4-epi-chlortetracycline (ECTC) (1, 10, 30 mg/L) on seed germination, growth, antioxidant enzyme systems, CTC and ECTC accumulation in pakchoi (Brassica campestris ssp. chinensis) seedlings were investigated using a water culture method. The results indicated that root elongation could be recommended as a sensitivity indicator to assess eco-toxicity of CTC and ECTC compared with other targets. The activities of SOD, POD and CAT of pakchoi were enhanced with increasing CTC concentration and the activities of POD and CAT were always higher than that of the control group. Under the same conditions, the SOD, POD and CAT activities were enhanced at a low concentration of ECTC but the latter two were inhibited at high ECTC concentration. CTC and ECTC can accumulate in pakchoi. When the concentration of CTC and ECTC was increased, the contents of CTC and ECTC accumulated in seedlings increased. The experiments revealed that the abilities of pakchoi to accumulate CTC were stronger than for ECTC and the stress was correspondingly greater.

SEM observation on pollen morphology of 12 lily species

ZHANG Yan-ni, QIAN Can

2011, 20(5):  111-118. 

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Pollen morphologies of 12 lily species (including 4 wild and 8 cultivated species) were examined by scanning electron microscopy (SEM). The pollen shapes of 4 wild (Lilium pumilum, L. davidi, L. lancifolium and L. leichtlinii var. maximowiczii) and 4 cultivated (Brunello, Prato, Pollyanna and Red knight) lily species were elliptic balls, while those of the other four cultivars (Algarve, Yelloween, Samur and Siberia) were a long ellipsoid. Most mesh ridges of the pollen from the 12 species were composed of particles or tumors and their width ranged from 1.20 to 2.78 μm. The shapes of pollen mesh are mostly irregular polygons to nearly round with sizes from 2.11 to 7.66 μm. The surface ornamentation of L. leichtlinii var. maximowiczii and Red knight pollens showed the coexistence of duplicolumellate and simplicolumellate, while the other 10 species were netted simplicolumellate. The forms of pollen grains were single, ellipsoidal in polar view and boat-shaped in equatorial view, with single-channel apertures the length of the ditch. Cluster analysis of pollen morphology for the 12 lily species showed that L. pumilum and L. davidi, L. lancifolium and L. leichtlinii var. maximowiczii, Algarve and Samur, Prato and Pollyanna have close genetic relationships. The 12 species can be divided into 3 groups based on cluster results.

Analysis of genetic diversity of salt tolerant alfalfa germplasms

JIANG Jian, YANG Bao-ling, XIA Tong, YU Shu-mei, WU Yun-na

2011, 20(5):  119-125. 

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The genetic structure and diversity of 25 alfalfa (Medicago sativa) salt-tolerant varieties was analyzed by RAPD technology. Results showed that the polymorphism loci percentages (P) of 30 primers between single-plant DNA of 25 salt-tolerant alfalfa varieties were 81.52%, and between mixed DNA of various varieties were 61.65%, indicating that single-plant DNA sample was a better method than mixed DNA sample, to reveal the level of genetic variation within and between alfalfa varieties. The coefficient of gene differentiation (Gst) mainly reflects the ratio of species variation to total variation, and the Gst of 18 Chinese salt-tolerant alfalfa varieties and 7 American salt-tolerant alfalfa varieties were 0.271 and 0.152, respectively, showing that there was more interactive gene exchange between Chinese salt-tolerant alfalfa germplasm was than that of American germplasm. Alfalfa is a typical outcrossing plant, and there was a direct link between their genetic structure and breeding system. Based on genetic distance (GD) analysis, 9 groups were obtained from the 25 varieties, of which, the GD of No.1 and No.2 Tumu was the least (GD=0.148), and that of No.1 Jieda and Tumu was the greatest (GD=0.786). Genetic diversity analysis of salt-tolerant alfalfa germplasm provided a theoretical basis for the repository building of alfalfa salt-tolerant core germplasm and for the selection and breeding of new salt-tolerant varieties.

Construction of differently expressed cDNA library of alfalfa by using suppression subtractive hybridization under the high temperature

SU Fang-rui, XU Hong, WANG Cheng-zhang

2011, 20(5):  126-132. 

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In order to isolate the high-temperature stress-induced ESTs from alfalfa, we took the alfalfa variety‘ABI 700’as material whose fall dormancy level was 6, and taking the cDNA from alfalfa tender stems and leaves under 45℃ as tester, while taking their cDNA under 22℃ (normal growth) as driver. The forward suppression subtractive library of alfalfa under high temperature stress was constructed by using suppression subtractive hybridization. Choosing 120 positive clones stochastically from the subtractive library to take bacterial PCR, it displayed the recombination rate of library clones was 97.8%. The size of inserted fragment was mainly between 300-750 bp. This research of the alfalfa differential expression has laid a theoretical basis for the cloning of heat-resistance gene and the gene expression under high temperature.

RAPD analysis of Cichorium intybu by space mutagenesis and high-yield strains’ selection

HAN Yong-fen, LU Xin-shi, SHU Jian-hong, FU Wei, LU Rui-xia, Qin Tao-ying

2011, 20(5):  133-141. 

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Cichorium intybu is a excellent forage with high yield and good palatability, which was introduced from abroad.It has been used in production widely. The genetic relationship and production performance of 29 C. intybu were studied in this research by using RAPD method. The result showed that 15 primers selected from 100 random primers were characteristic of high polymorphism, repeatability and stability. 78 DNA fragments were amplified, including 63 polymorphic bands. The average percentage of polymorphic bands was 87.77%, cluster analysis showed that genetic similarity coefficient of C. intybus was ranging from 0.69 to 0.80, there was a lower genetic diversity among germplasm resources of C. intybus tested. PA-186 clustered alone. The fingdings indicated an incomplete correlation among the dendrogram and phenotypic characteristics. According to production performance, the yield of twelve new lines were higher than Puna chicory (9.5 kg/m²)and Jiangjun chicory(9.7 kg/m²).

Establishment and optimization of an ISSR reaction system for Oxalis triangularis

HU Su, WANG Yong-qing, TAO Lian

2011, 20(5):  142-150. 

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An orthogonal design was used to optimize an ISSR(inter-simple sequence repeats)-PCR(polymerase chain reaction) amplification system for Oxalis triangularis, involving five levels of five main factors (Mg²⁺, Taq DNA polymerase, primer, template DNA and dNTP). The annealing temperature of suitable primers, which were selected from 100 random ISSR primers, was optimized and the reaction program was improved so that a suitable ISSR-PCR reaction system for O. triangularis was established. The reactions were performed in a 25 μL volume containing 2.5 μL 10×buffer, 1.25 mmol/L Mg²⁺, 0.9 U Taq DNA polymerase, 0.3 μmol/L primer, 60～100 ng template DNA, and 0.25 mmol/L dNTP. The optimized reaction program was: 94℃ for 5 min, followed by 40 cycles of 94℃ for 50 s, annealing at a suitable temperature for different primers for 60 s, 72℃ for 1.5 min, extension at 72℃ for 7 min and preservation at 4℃. The establishment of this system provides a theoretical basis and technical references for further research on the genus Oxalis by ISSR markers.

Analysis of cooperation effect of water and fertilizer on wheat and pea in dryland based on APSIM model

LI Guang, HUANG Gao-bao, WANG Qi, LUO Zhu-zhu

2011, 20(5):  151-159. 

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In order to explore the influence mechanism and regulation of the cooperation effect of water and fertilizer on yields of crops, APSIM (agricultural production system simulator) model and multiple regressions were used to explore the cooperation effect of water and fertilizer on yields of rotation system with wheat (Triticum aestivum) and pea (Pisum sativum) in loess hilly region of China. The parameters of APSIM model were firstly modified and then verified according to the data collected from field experiment. APSIM model was used to simulate yields of rotation system with wheat and pea within 30 years. The results showed that APSIM model can be used to simulate yields of rotation system with wheat and pea. The order of effect on yields of rotation system with wheat and pea is precipitation of growing stage (denote X₂)>precipitation of fallow period (denote X₃)>nitrogen fertilizer application (denote X₁). There was a diminishing return of nitrogen fertilizer application on yield of wheat. The optimum nitrogen rate was 65.0 kg/ha and 17.9 kg/ha, respectively. The order of cooperation effect on rotation system with wheat and pea is X₂X₃>>X₁X₃>X₁X₂. Cooperation effect of precipitation of growth stage and precipitation of fallow period was higher than others cooperation effect. Precipitation has a higher effect on crops yields than fertilizer application. At same time, cooperation of precipitation and fertilizer had a high effect on crops yields.

Simulation of energy balance of SVAT system in the farming-pastoral zone of the Loess Plateau

CHENG Xiang-rong, YU Mu-kui, HUANG Ming-bin, SHAO Ming-an

2011, 20(5):  160-168. 

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The energy transfer and distribution of the soil-residue-plant canopy layers in typical vegetation cover types were simulated from April to September in 2007, using one dimension water and heat transfer model SHAW (the simultaneous heat and water), at Liudaogou watershed in the farming-pastoral zone of the Loess Plateau. The results showed that the proportion of short wave radiation absorbed by plant canopy layer was more than soil layer and residue layer for Pinus tabulaeformis and Caragana korshinskii at the sun-facing slope, and for Medicago sativa at the shaded slope. For Stipa bungeana and Setaria italica at the shaded slope, the proportion of soil layer absorbed short wave radiation was higher. 91% of long wave effective radiation came from plant canopy layer for P. tabulaeformis at the sun-facing slope, and soil layer released less long wave effective radiation. However, the proportion of long wave effective radiation was higher in soil layer than the residue layer and plant canopy layer for C. korshinskii, M. sativa, S. bungeana and S. italica. The simulation of energy balance indicated that the energy outgoing components were latent heat, followed by sensible heat from M. sativa and S. italica at the shaded slope, and the energy outgoing components were contrary for S. bungeana at the shaded slope, P. tabulaeformis and C. korshinskii forest at the sun-facing slope.

Antifeeding and contact effects on extracts from 30 kinds of poisonous plants in natural grassland of Gansu Province against larva of Pieris rapae

HU Guan-fang, LIU Min-yan, LI Yu-qi, NIU Shu-jun, ZHAO Feng, SHEN Hui-min

2011, 20(5):  169-176. 

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Anti-feeding and contact effects of extracts from 30 kinds of poisonous plants from natural grasslands of Gansu province against fourth instar larvae of Pieris rapae were assessed by immersion methods. Methanol extracts from Aconitum pendulum, Thalictrum baicalense, Corydalis adunca, Ligularia virgaurea, Artemisia frigida, Peganum harmala, and Stellera chamaejasme had very strong anti-feeding and contact effects against the larvae of P. rapae, with anti-feeding rates between 82.23%-100.00% and contact mortalities between 80.00%-94.12% after 48 hours. Methanol extracts from A. gymnandrum, Euphorbia tibetica, E. fischeriana and E. helioscopia had very strong anti-feeding effects, of 95.14%-97.62% after 48 hours. The eleven kinds of poisonous plants were A. pendulum, T. baicalense, C. adunca, L. virgaurea, A. frigida, P. harmala, S. chamaejasme, A. gymnandrum, E. tibetica, E. fischeriana and E. helioscopia. They are worth further research and development.

Growth models and hybrid vigour of the F₁ lambs of Gansu alpine merino

LI Shao-bin, WANG Ji-qing, CHENG Shu-ru, LIU Xiu, YAN Wei, ZHANG Bao-yun, LUO Yu-zhu

2011, 20(5):  177-182. 

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The growth potential of Gansu Alpine Merinos was studied to select the optimal cross combinations and provide a theoretical basis for rationally using germ plasm resources. Logistic and Gompertz model were first used to fit the early growth progress of F₁ lambs of Gansu Alpine Merino, Texel (TG) and White Suffolk (WSG) breeds. At the same time, the observed values of growth and development of crossing lambs and parameter evaluation were analyzed to evaluate the hybrid vigour. Two models had a goodness of fit >0.99. The Gompertz model fitted well for TG but the Logistic model was better for WSG. The growth inflexion of male lambs and female lambs of TG was 60.15 and 56.24 days, and the inflexion weight of male lambs was 0.73 kg higher than that of female lambs; the growth inflexion of male lambs and female lambs of WSG was 78.20 and 72.08 days with an inflexion weight of male lambs that was 1.27 kg higher than that of female lambs. From 1-month-old to 6-months-old, the cumulative growth of male and female lambs of TG were all higher than those of male and female lambs of WSG (P<0.05). The biggest daily gain, instantaneous growth rate, relative growth rate and mature weight of model parameters of TG were all larger than those of WSG, while the average T_10-90 value of TG was smaller than that of WSG, which means that the early growth of TG lambs was better than that of WSG. The TG crossing model was therefore better than the WSG crossing model.

Effect of adding cellulase to alfalfa meal ration on production performance, egg quality and nutrient digestibility on layers

XIA Su-yin, WANG Cheng-zhang, ZHAN Fa-bai, YAN Xue-bing, LIU Qi-shuan, CHEN Yan-rong, LI Hai-yan,

2011, 20(5):  183-191. 

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The objectives of this study were to evaluate production performance, egg quality and nutrient digestibility of layers adding cellulase to alfalfa meal ration. An experiment was conducted using a total of 210 Highland Brown Layers aged 40 weeks to study those of index. Layers were randomly divided into 7 groups, 3 replicates for each group and 10 for each replicate. One of these groups was used as the control group, others were used as treatment groups including group I to group VI. The control group was fed the basic diet, group I to group VI were fed the diets containing alfalfa meal and cellulase in different levels (3%, 5%, 7%, 7%+0.1%cellulase, 7%+0.2% cellulase, 7%+0.3% cellulase), respectively. By a series experiment of feeding and digestion, the production performance, egg quality and nutrient digestibility of layers were measured in each group. The results showed that, 1) Layers fed diets added with alfalfa meal and cellulase had no significant difference for laying rate and egg weight (P＞0.05) than that of control group, however, average daily feed intake of the group III and feed/egg ratio of the group V were significantly decreased comparing with the control. 2)Addition of alfalfa meal and cellulase had no significant effects on egg white height, egg yolk pH, egg white pH, egg shape index, egg yolk index, and eggshell relative weight (P＞0.05), however, those of yolk color and eggshell strength, Haugh unit were significantly improved comparing with control, which egg yolk color was significant higher (P＜0.01) than that of control group and egg yolk color increased with the increasing of alfalfa meal. 3)The diets of adding alfalfa meal and cellulase significantly reduced the yolk malondialdehyde (MDA) content, which extend the shelf life of eggs. 4)There were no significant difference of dry matter, calcium, phosphorus digestibility among all groups (P＞0.05), but the apparent digestibility of crude protein, the crude fat, crude fiber and acid fiber in the group V increased by 14.79% (P＞0.05), 8.48% (P＞0.05), 15.91% (P＞0.05), 4.17% (P＞0.05), respectively,comparing with the group III. Generally, there were no significant difference of production performance, but it improved the egg quality, egg yolk color and digestibility of crude fibre and acid detergent fiber (ADF) as adding alfalfa meal and cellulase, recommending that 7% alfalfa meal+0.2% cellulase in the diet of layers.

The nutrient components and utilization of mulberry as animal forage

DU Zhou-he1,2, LIU Jun-feng2, ZUO Yan-chun1, ZHANG Jian-fei2, LIU Bin-bin2, CHEN Yi-an2, ZHU Yong-qun1, ZHOU Xiao-kang1

2011, 20(5):  192-200. 

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The mulberry tree (Morus alba) with a broad adaptability, is a classical dominance crop in China with high production and quality. The mulberry leaves contain rich nutrients and distinct functional factors. The utilization of mulberry as animal forage can make up the shortage of common green forage crops as well as reduce competition between human beings and livestock. In addition, the distinct functional factors can enhance the ability of animals and fowls to resist adversity and improve their products. Herb-cultivation of mulberry produced high yield and excellent benefits.

Characteristics of new forage rice and effects of additives on its silage quality

CHEN Ming-xia, LIU Qin-hua, ZHANG Jian-guo

2011, 20(5):  201-206. 

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Silage as a fermented product is increasingly becoming important to the production of animal husbandry. Rice silage is important to alleviate roughage shortage. The present work investigated the characteristics of new forage rice and effect of additives on its silage fermentation quality and aerobic stability. The ensiling treatments contained the addition of glucose at 2% FM (fresh matter) or pineapple residue at 10% FM, The inoculation of Lactobacillus rhamnosus or L. plantarum, and their combination. The silage fermentation quality and aerobic stability after ensiled for 100 days were investigated. The results showed that new forage rice contained more water soluble carbohydrates and the pH value was near to 4.6 when ensiled without any additives. The combination of L. plantarum and glucose had the best fermentation quality, with lowest pH and contents of acetic acid and NH₃-N, highest lactic acid content and ratio of lactic acid to acetic acid. L. rhamnosus inoculation alone had no significant effect on the silage fermentation quality. Glucose or pineapple residue addition had good aerobic stability when they were exposed to the air.

Soil nutrient in two-year alfalfa field on condition of film-mulching rainfall harvesting cultivation

KOU Jiang-tao, SHI Shang-li, ZHOU Wan-hai, YIN Guo-li, LI Jian-wei

2011, 20(5):  207-216. 

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Film-mulching rainfall harvesting cultivation method was applied to alfalfa(Medicago sativa)planting on condition of dry farming, ridge was used as rainfall collection area, and furrow was used as planting area to study the effect of various ridge-furrow ratios and mulching methods on soil nutrients of two-year alfalfa fields. The result showed that no significant difference in total phosphorus (TP) contents was found among the treatments before reviving period on the second year and after the mowing of second crop in soil layers of 0 to 20 and 20 to 40 cm; accordingly, soil organic matter (SOM) and total nitrogen (TN) contents increased as the increase of ridge width for ridges covered with soil and film in the two soil layers, and within the soil layer of 0 to 40 cm, SOM, TN, available nitrogen (AN), available phosphorus (AP), slowly available potassium (SAK) and available potassium (AK) contents were found significantly higher than ridges compacted with soil and CK (conventional tillage), among all the treatments, MR60 and MR75 were found with highest soil nutrient. Compared with after mowing and before reviving, decrease of SOM from 0 to 40 cm layer in ridges covered with film was found remarkably lower than ridges covered with soil, and the increase of TN as well as the decrease of AN, AP, SAK and AK in ridges covered with film were found remarkably higher than ridges compacted with soil. According to related analysis, within soil layers between 0 to 40 cm, significant negative correlation was found between the decrease of SOM and the economic yield of alfalfa, and significant positive correlation was found between the economic yield of alfalfa and the increase of TN, the decrease of AP and AK, indicating that film-mulching rainfall harvesting cultivation inhibited the decrease of SOM effectively, and the inhibition effect of film was found better than soil, simultaneously, increase in TN content was found promoted and soil nutrient in soil layers from 0 to 40 cm was found increased, which is good to the sustainable utilization of soil.

Effect of potassium fertilizer and plastic film mulching on growth and size inequality in Lilium davidii var. unicolor

YANG Yu-hua, LI Wen-long, HUANG Peng, ZONG Jian-wei, LI Zi-zhen

2011, 20(5):  217-222. 

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The effect of K supply regimes and plastic film mulching on the harvest index (HI), reproductive allocation (RA) and size inequality of Lilium davidii var. unicolor population, was determined and the underlying mechanisms were explored. Compared with K₀ treatment, bulb yield, biological yield, HI and RA of L. davidii treated with K fertilizer increased 44.42%, 20.60%, 14.30% and 5.55% respectively under non-mulching conditions, while the increases were 57.21%, 13.89%, 23.30% and 7.35% respectively under mulching conditions. Either with mulching or non-mulching, size differences always decreased along the K supply gradient. The bulb yield and biological yield of L. davidii under mulching conditions increased by 15.59% and 13.09%, respectively compared with those under non-mulching conditions. However, HI and RA under mulching conditions were lower by 4.19% and 3.20% respectively than those under non-mulching conditions. Results suggest that the size inequality of L. davidii populations are closely correlated with K supply, and that under greater K supply there were relatively larger plants with higher HI. Growth redundancy under mulching conditions occurred in L. davidii populations, which may result from the exacerbated interplant competition and greater size inequality. Although there was a significant increase in bulb yield, L. davidii cultivation with plastic film mulching was not always the best method.

Effects of nitrogen on yield, nutrient accumulation and quality of Lanzhou lily

LIN Yu-hong, LUO Jun-jie

2011, 20(5):  223-230. 

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Dry conditions in the field by field experiment to study the application of phosphate (P₂O₅) 150 kg/hm², potash (K₂O) 225 kg/hm², based on different nitrogen levels (0,75,150,225 kg/hm²;N0,N75,N150,N225) of lily yield, nutrient uptake and quality. The results showed that one, two, three years production of raw annual growth rate of lily, respectively (51.69±25.76)%, (110.71±40.85)%, (88.29±21.45)%, the largest increase for the second year, followed by the third year. Lily total sugar, starch and soluble sugar content increased with nitrogen rate generally decreased, following increasing content of crude fiber and crude protein increased as nitrogen rate was high after the first drop and then increase the trend, which lily under nitrogen content of crude protein were higher than N0, and soluble sugar content were lower than N0. When nitrogen is 75 kg/hm², the total sugar and starch content increased significantly compared with N0 (an increase of 3.3% and 5.1%, P＜0.05). When the nitrogen application rate of 225 kg/hm², the soluble sugar content was significantly decreased compared with N0 (down 6.2%, P＜0.05). When nitrogen is 75 kg/hm², the crude protein content increased significantly compared with N0 (an increase of 20.3%, P＜0.01), and when the nitrogen application rate of 225 kg/hm², the ratio of N0 was increased significantly (an increase of 37.9%, P＜0.05). Nitrogen is the impact of yield and quality of lily one of the main factors.

Study on biology characteristics and harmfulness of Kummerowia striata in Changde

WANG Yun, XIANG Qun, PENG You-lin

2011, 20(5):  231-236. 

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The biology characteristics and harmfulness of Kummerowia striata were investigated. The highest plant height was (10.76±0.73) cm, the lowest (4.15±0.55) cm, and the average (6.46±2.58) cm. The longest main stem length was (22.33±3.31) cm, the shortest (9.02±0.74) cm and the average (12.07±4.61) cm. The maximum winding number was 61±18.16, the least 14±4.16 and the average 27±15.44. The longest branch length was (7.34±1.26) cm, the shortest (4.31±0.77) cm and the average (5.29±1.25) cm. The maximum number of seeds was 334±138.06, the least 51±24.24, and the average 120±97.83. The maximum root distribution area was (1 587.79±979.15) cm², the minimum (101.65±32.67) cm², and the average (352.68±595.96) cm². The longest root branch was (6.78±2.08) cm, the shortest (3.35±0.90) cm and the average (4.28±1.38) cm. The most root branches were 15±6.96, the least 7±0.58 and the average 10±3.24. The maximum plant coverage was (23.89±11.09)%, the minimum (2.44±0.96)% and the average (6.71±7.86)%. The maximum planting density was 6±2.49, the minimum 4±1.00, and the average 5±1.58. A few associated plants of K. striata with low density and coverage also occurred.

Study on fertilizer and planting depth in bermudagrass sprigs growth and establishment

ZHANG Xu, WANG Quan-zhen, CUI Jian, RAYMOND S A

2011, 20(5):  237-244. 

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The influence of fertilizing and planting depth on establishment and growth of Cynodon dactylon (bermudagrass sprigs) for golf course preparation was investigated. A field experiment on golf course preparation was based on a two factor randomized block design with experimental factors of planting depth (1, 2 and 3 cm) combined with fertilizing before and after planting. The coverage, density and height of C. dactylon during growth and establishment increased with planting depth but; there was no significant difference between 2 and 3 cm planting depth in the later growing period. There was better establishment with fertilizing after, but not before, planting. Planting depth of C. dactylon was more important than fertilizing, and there was a significant interaction between the two experimental factors. A planting depth of 2 cm and fertilizing with quick releasing fertilizer one week after planting C. dactylon is recommended taking into account the costs and time limit in industrial production.

Impact of climate change on water requirement of main crops in irrigated oasis of Hexi corridor

WANG He-ling, NIU Jun-yi, WANG Run-yuan, LV Xiao-dong

2011, 20(5):  245-251. 

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The crop water requirement is one of the most important factors in farmland water circulation system. study the effects of climate warming on water requirement of major crops in irrigated oasis in Hexi corridor when 1-4℃ temperature rise in the future scenarios. The results show that climate change will have great impact on water requirement of cotton and corn, followed by spring wheat. when the temperature rises 1-4℃ during the growth period, cotton, water requirement of cotton will increase by 2.17%-12.66%, equivalent to 15.00-83.00 mm; corn will increase by 1.90%-11.49%, equivalent to 14.60-82.50 mm; wheat will be increase by 1.80%-10.03%, equivalent to 9.70-50.70 mm.There are certain regional differences which the impact of climate change on crop water requirements. When the temperature increases 1℃, the crop water requirement of Wuwei in arid regions slightly larger than Dunhuang in extreme arid region; When increases 2℃, the demand almost equivalent. Dunhuang is greater than the Wuwei if increased 3 and 4℃. According to the current planting planning in Hexi Oasis, the given temperature scenario will cause an additional water requirement of 0.11,0.21,0.37,0.62 million m³ for cotton, 0.16,0.33,0.56, 0.93 million m³ for corn; and 0.14,0.26,0.45,0.71 million m³ for spring wheat. The total irrigation water increase 0.41,0.80,1.38,2.25 billion m³. Climate warming will make the situation of water shortage more severe.

Review in the study of comprehensive sequential classification system of grassland

LIANG Tian-gang, FENG Qi-sheng, HUANG Xiao-dong, REN Ji-zhou

2011, 20(5):  252-258. 

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Grassland type is an abstract and generalization of grassland resources entity while grassland classification is not only the concrete practice of grassland type theory, but is also one of the foundations of grassland science research and practice. On the basis of bio-climatic features, the grassland Comprehensive and Sequential Classification System (CSCS), sorts grasslands with the same zonal agricultural climate characteristics as one category according to the different heat and humidity grades. The classification retrieval map made by this principle is the mapping expression of CSCS and it has a unique theoretical and practical value. With the increasing improvement and perfection of RS, GIS, GPS and other techniques and the geo-statistical interpolation methods for meteorological indicators, the CSCS in both theory and practice has made many achievements over the last 50 years since it was proposed in the 1950s. This paper systematically summarizes the role and meanings, study advances, and existing problems, as well as research prospects of grassland CSCS, which it is anticipated will provide a scientific basis for its extension and application on a large scale.

General situation of studies on grassland application of municipal sludge compost

YU Fang-fang, CHANG Zhi-hui, HAN Lie-bao

2011, 20(5):  259-265. 

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This article discusses current research, development trends, advantages and achievements of the use of bio-solid on turf-grass, based on characteristics of the bio-solids. On the premise of controlling environmental risk and composting treatment, the use of bio-solids on turf-grass has the advantages of making use of the nutrients in the bio-solid to improve turf-grass growth, soil physical and chemical properties, while, the turf-grass can purify the bio-solids. However, because bio-solids from different sources have different qualities, it is difficult to determine the amount of bio-solid to be used. There is also controversy about pollution from pathogens, heavy metals and other pollutants. The authors hold the view that research should focus on the effects of bio-solids on turf-grass physiological changes and control of bio-solid quality, thus providing theoretical instruction and technical support for future research on the use of bio-solids on turf-grass.

Review for effect of Lactobacillus buchneri on the silage

HONG Mei, DIAO Qi-yu, JIANG Cheng-gang, YAN Gui-long, TU Yan, ZHANG Nai-feng

2011, 20(5):  266-271. 

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The hetero-fermentative lactic acid bacterium, Lactobacillus buchneri, has changed the definition and standards of inoculum, since it differs from homo-fermentative lactic acid bacteria and can improve the aerobic stability of silages. The effects of L. buchneri on fermentation, aerobic stability of silages and animal performance including present application conditions are reviewed and future directions for L. buchneri development are proposed.

Spatial and temproal pattern of Seriphidium seedling in small-scale under two gradient degradation

LU Wei-hua, ZHU Jin-zhong, JIN Gui-li

2011, 20(5):  272-277. 

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Using survival test method to analyze survival rate of Seriphidium seedlings in SD (serious degradation) and HD (heavy degradation), there were not significant difference in the survival rate of seedling between SD and HD. using O-ring function and CIM (combining the data from individual mapped replicate plots into mean) technology to analyze spatial pattern of seedlings in small scale under two degraded gradation, the results showed that density function value decreases with increase in scale, the highest aggregation intensity reduce and that spatial scale of aggregation intensity climax increase from June to September, changing trend of aggregation intensity of seedlings in spatial and temporal is analogical under two degradation region, pattern of seedling emergence depend on maternal plant intensively, the maximum distance of seed dispersal is 50 cm respectively in SD and HD, scale of seedlings concentrative is about 5-30 cm, and dependence of seedlings on maternal plant increase in time scale. Convert distribution pattern of seedling to increase individual fitness in spatio-temporal scale.

Evaluation of fruit energy value of Polygonum viviparum in the Aba Plateau

KUANG Yu, SUN Fei-da, GAN You-min, FENG Guo-ying, CAI Zhuo, MA Chao

2011, 20(5):  278-283. 

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Fruit yield, total sugar, and calorific value were chosen to study energy potential of Polygonum viviparum, in Hongyuan, Ruoergai and Songpan. The results showed that, 1) Fruit yield and total sugar, differed significantly in 7 plots (P<0.001), with levels in plot 3 significantly higher than in the other samples (fresh weight 117.222 g/m², dry weight 46.226 g/m²). The highest total sugar was in plot 5 (54.16%), and the average was 49.73%. The calorific value of fruits in plots 2, 3 and 7 did not show regularity: the average was 15.85 MJ/kg. 2) Correlation analysis showed that fruit dry weight had a significant negative correlation with altitude, but a significant (P<0.05) positive correlation with coverage of P. viviparum and aboveground litter storage, while the impact of various factors on total sugar was not significant. 3) Statistics for the grassland areas showed the fruit annual yield in Hongyuan is from 17 387.81 to 105 674.34 t (fresh weight), in Ruoergai it is from 15 172.04 to 92 208.01 t (fresh weight). The annual total sugar in Hongyuan is from 8 646.96 to 52 551.85 t, in Ruoergai it is from 7 545.06 to 45 855.04 t, P. viviparum is expected to become a potential wild carbohydrate energy plant.

A taxonomic study on genus Lyophyllum in Qilian Mountain Nature Reserve

GUI Jian-hua, WEI Sheng-long, WANG Sheng-rong

2011, 20(5):  284-287. 

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Using traditional taxonomic methods, fungi in the genus Lyophyllum were collected in the Qilian Mountains, identified, and classified. They were divided into eight biological species of which four are new to Gansu province: Lyophyllum semitale, L. loricatum, L. shimeji, L. aggregatum.

Studies on the pretreatment of Pennisrtum purpureum×P. typhoideum by dilute sulfuric acid

ZHANG Shi-qing, GE Chang, YI Ke-xian

2011, 20(5):  288-293. 

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Pennisetum purpureum×P. typhoideum cv. Reyan No.4 was pretreated by the dilute acid method and reducing sugars in the hydrolysate was measured by the DNS method. After separate analysis on sulfuric acid concentration (v/v), solid-to-liquid ratio(g/mL), hydrolysis temperature, hydrolysis time and the different granularity, the optimum pretreatment conditions were obtained by the quadratic general rotary unitized design. The optimum pretreatment conditions were a hydrolyzing temperature of 117℃ for 15 min with 3% (H₂SO₄), a solid-to-liquid ratio of 1∶15 and a granularity of 0.425-0.850 mm.