Table of Content

20 February 2010, Volume 19 Issue 1

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Grassland culture is an integral part in Chinese culture

REN Ji-zhou

2010, 19(1):  1-5. 

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Nomadic people play an important role in managing grasslands. Nomadism is a fundamental element of grassland culture, and a proper understanding of the nomadism is essential for the conservation of grassland culture. Nomadism is the earliest bionics in the history of human civilization, its core plays positive role in developing modern agriculture. Grassland culture has made a significant contribution to integrate different cultures across vast areas of land as nomadic activity was shifted from managing livestock by foot to riding. As the consequence of system coupling between the grassland culture and cropping culture both ecological and economical effects will be taken place. The net impact of this system coupling is seen as being positive to Chinese culture, which can be called an ‘Orogenic Movement’ of culture. Grassland culture will continuously support human civilization since it has always been an active element in the development of Chinese culture.

A study on niches of dominant species of subalpine meadow in the Yunding Mountain

LI Bin, LI Su-qing, ZHANG Jin-tun

2010, 19(1):  6-13. 

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TWINSPAN was used to divide 36 quadrates of subalpine meadow in the Yinding Mountain into five types of communities as five resource states. Niche breadths and niche overlaps of dominant species of the subalpine meadow were measured and analyzed using the indexes proposed by Levins, Shannon-Wiener, and Petraits. Niche breadth of Kobresia bellardii was the biggest among the ten dominant species with a Levins niche breadth of 8.78 and Shannon-Wiener niche breadth of 31.58. The species had extensive adaptation to the environment. The bigger the species’ niche breadths in the subalpine meadow, the more extensive were their adaptation to the environment and the stronger their capabilities of using resources. The greater were the species’ niche overlaps, the greater were the ecological similarities between species and their resources-use. The niche overlaps of the dominant species in K. bellardii and Taraxacum mongolicum communities were the biggest (0.914), and the two species had common characteristics of resource use.

Plant diversity variations in zokor-mound communities along a successional stage in sub-alpine meadow

YANG Ying-bo, XIN Xiao-juan, Ai-de-xie-cuo, YANG Xue, WANG Shao-mei, CHU Cheng-jin, REN Zheng-wei, WANG Gang

2010, 19(1):  14-20. 

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Plateau zokor is one of the major rodents in subalpine meadow, They frequently consume plant roots and entire plants, largely destructing the grassland. Meanwhile, they excavate burrow systems and deposit the soil aboveground, then creating new sites that can initiate succession at a local scale. We investigated the community structure on the zokor mound, the results indicate that: 1) There is a continuous increase in species richness with succession. 2) Shanon-Weiner index also show species diversity may peak at the late stage, even higher than the matrix meadow. 3) Using the community heterogeneity index to measure different mound communities, it suggested that the variation is greater in early secondary succession, and the variation will decrease over time. It is a good evidence to prove that the succession of mound is a process from divergence to convergence.

A study on species diversity of a Gymnocarpos przewalskii community in the Subei desert

CHAI Yong-qing, CAO Zhi-zhong, CAI Zhuo-shan

2010, 19(1):  21-27. 

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During 2006-2008, distribution and community characteristics of Gymnocarpos przewalskii which is a type of rare plant in the north of Subei were investigated. G. przewalskii is mainly distributed on Piedmont alluvial fan, gravel and dry river bed areas at altitudes of 1 500-1 600 m in the northern mountainous area of Subei and 1 900-2 780 m in the southern mountainous area of Subei. Species composition of G. przewalskii plant communities consist of 44 species that belong to 31 genera 13 families. Among them, the gravelly desert distribution elements are in the ancient Mediterranean and West Asia to Central Asia (54.8%). There is close relationship between the floras of G. przewalskii desert communities and those of the ancient Mediterranean. The North temperate distribution pattern takes second place (19.4%). Distribution of G. przewalskii has a strong relationship with floras in North temperate distribution patterns. World distribution of the species is 9.7%. The diversity indexes of the floras are all high, but physical height and cover of floras are low. The number of old plants is more than that of young plants, which implies that the whole floras show a trend of recession.

Effect of neighbor grasses interference on the architecture of Trifolium repens

LI Xiang, WANG Ping, SUN Shou-mei, BAO Guo-zhang

2010, 19(1):  28-34. 

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The result of experiment of plant thinning showed that the competition between three groups of grasses (Lolium perenne, Dactylis glomerata, D. glomerata+L. perenne)and Trifolium repens was significant, so was the effect of the competition on the architecture of T. repens. The order of competitive balance index were, D. glomerata+L. perenne>D. glomerata>L. perenne so was the competitive index with the value of 0.32, 0.47, 0.71, respectively. With the increase of competitive index of grasses and T. repens, either density of architecture and branch, or branching intensity,branching angle and caloric content of T. repens decreased while the internode length increased significantly. The trend of change of energy allocation of root and stem of certain length was the same of that of the density of architecture.

Grassland unilization and feed budget of Tan-sheep under grazing conditions in Ningxia arid grassland

YANG Zhi-ming, LI Jian-long, DU Guang-ming, LI Guo-liang, LIU Xiang-ping, WANG Ning

2010, 19(1):  35-41. 

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Grazing trail was conducted with Tan-sheep at Ningxia arid grassland during the period of May to October, 2003, the daily intake quantity, intake rate and herbage standing biomass were determined. The objectives of the trial were to determine grassland utilization rate so that the grasslands with the similar conditions could be utilized properly after a long term close. The results showed that the standing biomass was fluctuated during the grazing season. Grazing intensity had significantly effecs on the standing biomass both in quantity and date when it reached the peak. There was a significant negative correlation between daily feed intake of Tan-sheep and grazing intensity, and expressed as: y=2.04－0.54x(R²=－0.85,n=55),where y is daily intake and x is grazing intensity. During the grazing season, feed intake of Tan-sheep increased as it progessing and then decreased later, the intake also showed seasonal fluctuations. It suggested that the grassland utilization rate by grazing was 10%-15% under experimental conditions. In the practice grassland carrying capacity should be determined by the multifactors and can not solely decided by standing biomass.

Analysis of soil respiration diurnal dynamics and factors influencing it in enclosednatural grasslands under different topographies in the Loess Plateau

LI Zhi-gang, HOU Fu-jiang

2010, 19(1):  42-49. 

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The diurnal dynamics of soil respiration in enclosed grasslands of gullied-hilly areas of the Loess Plateau, were measured by closed chamber infrared CO₂ gas analyzer and the relationships between soil respiration and soil temperature, soil water content, underground biomass and topography were analyzed. Diurnal soil respiration showed a single-peak curve with the lowest value of 0.393-1.103 μmol/(m²·s) in the early hours of the morning and a peak value of 1.034-1.405 μmol/(m²·s) at 14:00. A sine curve could be fitted to the data and all relationships between soil respiration rate and soil temperature could be depicted by an exponential function. There were differences in soil daily average respiration rate between plots: In flat grassland it was 1.229 μmol/(m²·s); on north-east facing grassland slopes of 15°, 30°, and 45° it was 1.138 ,1.033 and 0.890 μmol/(m²·s), respectively, while on similar south-west facing slopes it was 1.036, 0.859, and 0.379 μmol/(m²·s), respectively. Soil respiration rate declined as slope increased, and that of south-west facing grassland was lower than that of north-east facing grassland, changes that were consistent with soil water content and underground biomass. These differences were determined by spatial distribution differences of soil water content and underground biomass which were affected by topography, but there was no effect of temperature between plots.

Effects of altitude on seed size on the eastern Qinghai-Tibetan Plateau

GUO Shu-qing, QI Wei, WANG Yu-lin , MA Xiong, CHEN Xue-lin, DU Guo-zhen

2010, 19(1):  50-58. 

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Seed size was studied in relation to altitude, growth form and phylogeny across 600 species on the eastern Qinghai-Tibet Plateau. 1) Considering the whole flora, seed size decreased with altitude(n=600, R²=0.029, P<0.001), in accord with previous studies; 2) The decline in seed size with altitude was significant within grasses(n=512,R²=0.026,P<0.001), but not within shrubs(n=72, R²=0.004, P=0.616), or trees(n=16, R²=0.005, P=0.795). 3) t-tests found that seeds of higher region species were 11.5% larger than seeds from lower region species of the same genus(df=131, t=2.724, P=0.007), but smaller than the threshold ±30%, so, there was no significant effect between seed size and altitude within a genus. This is in contrast to other studies that have found a positive correlation. Compared with seed size of species collected from lower regions in the 132 grass species-pairs 40.9％(54 species) of, higher species had larger seeds, 19.7％(26 species)had smaller, and 39.4％(52 species)had no difference. There was no uniform pattern relating seed size to altitude. In different genera, seed size responses to environment have varied over long-term ecological time.

Effects of experimental warming on the carbon and nitrogen contents of Calamagrostis angustifolia

DOU Jing-xin, LIU Jing-shuang, WANG Yang, ZHAO Guang-ying

2010, 19(1):  59-66. 

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To determine the effects of warming on carbon and nitrogen contents of Calamagrostis angustifolia, a warming experiment was conducted under flooded and non-flooded conditions in a typical C. angustifolia meadow wetland of Sanjiang Plain, Northeast China. Warming cables were used to simulate soil warming. During the growing season, aboveground and belowground biomass of C. angustifolia increased by 67.24% and 48.83% under warming treatment, and by 45.21% and 78.13%, respectively under the interaction of warming and flooding. Experimental warming significantly enhanced carbon and nitrogen accumulations of C. angustifolia, and reduced C/N of the aboveground and belowground parts. Under warming treatment, carbon and nitrogen accumulation increased by 48.90% and 104.2%, while C/N of the aboveground and belowground parts decreased by 8.44% and 5.26%, respectively. Moreover, carbon and nitrogen accumulation of aboveground parts showed a significant increase under the interaction of warming and flooding. 1-3℃ soil warming significantly increased the biomass and carbon and nitrogen accumulation of C. angustifolia, thus affecting the carbon sequestration in freshwater marsh ecosystems.

Distribution characteristics of soil nitrogen during the greening period of forageunder different alpine grasslands in the eastern Qilian Mountain

YANG Cheng-de, CHEN Xiu-rong, LONG Rui-jun, MAN Yuan-rong, ZHANG Jun-zhong

2010, 19(1):  67-74. 

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Seven different alpine grassland types [Rhododendrons brushland (DJ), Salix cupularis brushland (GL), Potentilla fruticosa brushland (JL), Polygonum viviparum grassland (ZY), Grass steppe (HC), Swamp grassland (ZZ) and Kobresia grassland (SC)] in the eastern Qilian Mountains of the Qinghai-Tibetan Plateau, west China, were investigated for their soil nitrogen [Including microbial biomass nitrogen (MBN), soil total nitrogen, K₂SO₄-extractable nitrogen, alkali-hydrolysable nitrogen and nitrogen density] and their co-relationships. Soil total nitrogen, alkali-hydrolysable nitrogen, and nitrogen density varied from 4.2 to 7.9 g/kg, 104.1 to 234.0 mg/kg, and 0.38 to 0.61 kg/m², respectively. In 2005 and 2006, K₂SO₄-extractable nitrogen ranged from 3.4 to 11.4 mg/kg and 1.8 to 13.9 mg/kg, respectively. The contribution of K₂SO₄-extractable nitrogen to MBN varied from 3.93% to 11.62% in 2005 and 3.88% to 15.37% in 2006. MBN ranged from 49.0 to 143.0 mg/kg in 2005 and 35.9 to 171.7 mg/kg in 2006. MBN showed a significant positive correlation at P<0.05 with K₂SO₄-extractable carbon under brushland and a significant positive correlation at P<0.01 with K₂SO₄-extractable carbon under grassland. It also showed a significant positive correlation at P<0.01 with K₂SO₄-extractable nitrogen under DJ and GL, and a significant positive correlation at P<0.05 with K₂SO₄-extractable nitrogen under JL, ZY, HC, ZZ and SC. With the exception of SC, MBN showed a significant positive correlation at P<0.01 with MBC or MBP. The contribution of K₂SO₄-extractable nitrogen or MBN to soil total nitrogen varied from 0.07% to 0.16% and 1.16% to 1.93% respectively in 2005. In the eastern Qilian Mountains of the Qinghai-Tibetan Plateau, the values of total nitrogen, K₂SO₄-extractable nitrogen, and alkali-hydrolysable nitrogen were differed between the different types of grassland. Furthermore, the type of grassland was the deciding factor for quantity and ecological distribution of soil MBN and plant communities, and was the important factor influencing their quantity and ecological distribution, and the co-relationship between MBN and K₂SO₄-extractable nitrogen or K₂SO₄-extractable carbon. The co-relationship between MBN and MBC or MBP was decided by soil microorganism communities or their community structure.

Effects of conservation tillage on crop yield and carbon pool management index on top soil withina maize-wheat-soy rotation system in the Loess Plateau

YANG Jing, SHEN Yu-ying, NAN Zhi-biao, GAO Chong-yue, NIU Yi-ning, WANG Xian-zhi, LUO Cai-yun, LI Guang-di

2010, 19(1):  75-82. 

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The effects of conventional tillage (t), conventional tillage with stubble retention (ts), no-tillage (nt), and no-tillage with stubble retention (nts) treatment on crop yield,soil total nitrogen and carbon, total organic carbon,oxdizible organic carbon, and carbon pool management index (CPMI) were investigated within a maize-wheat-soy rotation system in the western Loess Plateau. Total crop yield for ten harvests during the years 2001 to 2007 under ts and nts treatments increased by 3.63 and 1.62 g/kg compared with conventional tillage, but decreased by 2.48 g/kg on the nt treatment. Total nitrogen contents under nts treatment were 15.4%, 30.2% and 16.2% higher than t, ts and nt treatments. Total carbon under nts treatment was significantly increased by 2.04 g/kg and total organic carbon were 2.50, 1.56 and 1.70 g/kg higher than under t, ts and nt treatment, respectively. Easily oxdized organic carbon under nts was 2.13 g/kg higher than under t treatment. TN/TC decreased by 12.75%,15.97%,6.87% and 24.16% under t, ts, nt and nts treatments. The CPMI under ts, nt and nts were 12.6%,20.1% and 46.6% higher than under t,both stubble retention and no-till were beneficial to increasing the soil organic carbon content and improving the quality of the carbon pool.

A study on the response and on the comparison of physiological and biochemicalindexes of four Lolium perenne varieties under PEG stress

WAN Li-qiang, LI Xiang-lin, SHI Yong-hong, HE Feng, JIA Ya-xiong

2010, 19(1):  83-88. 

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Response of physiological and biochemical indexes in leaves of four Lolium perenne varieties was compared under simulated drought stress using different concentrations of PEG solution. “Oupec”, with the highest relative water content and least decreasing changes, the lowest electrical conductivities,and the smallest increasing rates of MDA contents under PEG stress had more tolerant membrane systems and was the most resistant to osmotic stress, while the resistance of “Polim” was relatively weaker. Proline accumulation in leaves of the four varieties increased and “Oupec” with rapid increases in proline contents had the strongest resistance to PEG stress. Activities of superoxide dismutase (SOD) in leaves of the four varieties increased during the initial stress stages (5% PEG) and decreased continuously with more severe stress. “Oupec” and “Polim” had the strongest and the weakest drought resistance respectively. The four L. perenne varieties had reduced relative water contents and activities of superoxide dismutase (SOD), increased permeability of plasma, MDA contents and proline accumulation under PEG stress and had differences in rates of change for the response indices.

The signaling molecule H₂O₂ improved the heat-tolerance system of Festuca arundinaceaby up-regulating antioxidative activity

WANG Yan, LI Jian-long, YU Zui, XUE Feng

2010, 19(1):  89-94. 

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Cool-season turfgrass Festuca arundinacea was pretreated with 10 mmol/L H₂O₂ in pot experiments, and the regulation of the antioxidative system by exogenous H₂O₂ and its effects on heat-tolerance were studied. Exogenous H₂O₂ may activate the defensive system in F. arundinacea ahead of heat stress, and alleviate oxidative damage resulting from subsequent heat stress. CAT and POD activities were not significantly increased by exogenous H₂O₂ treatment. Heat stress itself increased POD activity, and POD may play a more important role in improving heat resistance of the turfgrass. H₂O₂ significantly affected the AsA-GSH cycle in F. arundinacea. APX, GPX and GR activities increased 20%-110% and GSH/GSSG significantly decreased 80% in the cycle, and were closely associated with the acquirement of heat tolerance in F. arundinacea. The signaling molecule H₂O₂ can improve the heat-tolerance of F. arundinacea by regulating the antioxidative system.

Effects of low temperatures on physiological and biochemical indexes and growth of Asarum splendens

CAI Shi-zhen, PAN Yuan-zhi, CHEN Qi-bing, YE Chong

2010, 19(1):  95-102. 

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Physiological and biochemical indexes, including electrolyte leakage, malondiadehyde, free proline and soluble sugar content of Asarum splendens leaves were measured in both natural and room controlled temperatures of 4℃, 0℃ and -4℃. The above indexes increased from November 2007 to January 2008 as temperatures decreased. The measured indexes increased as the stress time extended. The field plants grew well in conditions of natural low temperature and the room plants also grew well in conditions of cold stress at 4℃ and 0℃, but the room controlled plants could not grow and develop well with a stress of -4℃. Comprehensive analysis indicated that A. splendens could resist low temperatures above 0℃, but not -4℃ or below.

Effects of different N application methods and levels on the biologicalcharacteristics and nitrate content of ryegrass

characteristics and nitrate content of ryegrassHUANG Qin-lou, ZHONG Zhen-mei, CHEN En, CHEN Zhong-dian, HUANG Xiu-sheng

2010, 19(1):  103-112. 

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Agronomic traits such as yield, quality and nitrate content of gramineous forages are closely related to nitrogen level. Field experiments were conducted to study the effects of six urea application levels and four application methods on the agronomic traits, yield, quality, and nitrogen producing efficiency of ryegrass. Correlations among yield, crude protein content, amino acid content, N application amount and many agronomic traits were also investigated. Tiller number, plant height, yield, crude protein content, amino acid content and nitrate content significantly increased with increasing N application. However, effects of N application on ryegrass became less and nitrogen production efficiency became low with further increasing N application amounts. When N application was over 100 kg/hm² after each cutting, N fertilizer increased crude protein content but had little influence on amino acid content. When N application reached 250 kg/hm² after each cutting, plant height and yield showed decreasing trends. When N application was over 150 kg/hm², nitrate N content increased significantly, and even exceeded the 25% poisoning criterion. There were positive correlations among yield, plant height, tiller number, crude protein content, and nitrate N content of ryegrass. The yield was significantly correlated with the N application amount of broadcast applications. Crude protein and amino acid content were significantly or extremely significantly correlated with N application amount. Moreover, there was an extremely significant correlation between nitrate content and N application amount. Deep application influenced tiller number and plant height, and increase yield, crude protein and amino acid content.

Effects of conservation tillage on photosynthetic characteristics andprotective enzyme activity of Isatis indigotica

YANG Jiang-shan, ZHANG En-he, HUANG Gao-bao, ZHANG Ren-zhi

2010, 19(1):  113-120. 

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Effects of different tillage practices, i.e. T, NT and NTS, on photosynthetic characteristics, WUE, chlorophyll content and protective enzyme activity of Isatis indigotica were studied in different months. Diurnal change of Pn was a typical bimodal curve in different months, the diurnal average and annual average of Pn displayed NTS＞NT＞T. Gs had a flood tide in the morning,then falled to a low level fluctuation. The diurnal average and annual average of Gs displayed NTS＞NT＞T too.WUE diurnal change was similar to Gs, had no correlation to Pn. WUE diurnal average were NTS＞NT＞T in June and August,but T＞NT＞NTS in October,and WUE annual average were NTS＞NT＞T.It indicated that conservation tillage could storage water in soil,especially NTS.And in growing later season, moderate drought was propitious to improve WUE.Ci and Pn diurnal variation showed a marked negative correlation, it indicated that Pn lunch break due to stomatal limitation. Tr diurnal change was a typical bimodal curve in different months,and showed significant positive correlation with Pn. The diurnal average and annual average of Tr were NTS＞NT＞T also.Conservation tillage improved Chla and Chl(a+b) content significantly, and all the annual average of Chla, Chlb, Chl(a+b) and Chla/Chlb were NTS>NT>T. NT and NTS delayed Chla degradation,then enhanced Pn, NTS had the best effect of all. Conservation tillage improved CAT activity markedly in dry months of June and October,and improved SOD activity of NTS markedly in higher temperature.Because of SOD, POD and CAT coordinated protection,cellmembrane lipid peroxidation injury was reduced significantly.MDA annual average was T>NT>NTS.It illustrated that protective enzyme activity enhancing under NTS and NT,especially NTS,made a good physiological basis to Pn boost and normal growth of I. indigotica.

A study on the introduction and cultivation of American alfalfa in semi-humid area

YANG Hong-shan, CHANG Gen-zhu, ZHOU Xue-hui, MIAO Xiao-lin, LU Yuan, WANG Yong-lin

2010, 19(1):  121-127. 

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Alfaking, Fields, Pyramid, Reward, Simplot2000, Norva, Hopeland, Multifoliator, Leafking were introduced from American by Lanzhou Institute of Animal and Veterinary Pharmaceutics Sciences, CAAS. These alfalfa species are new American breeds which will be put into the Asian market in the next few years. After completing district tests in arid and semi-arid areas, we cultivated the varieties in a semi-humid area in 2008. Nine introductions of alfalfa grew normally in the semi-humid area and completed all the reproductive cycle with no problems, including no plant diseases and insect pests. An analysis of reproductive periodicity, nutrition component, speed of growth and stem/leaf ratios, showed the daily growth of Fields was 1.47 cm/d and the stem/leaf ratio was 0.7. The daily growth of Alfaking was 1.39 cm/d, and the thick albumen content was 17.57%. The daily growth of Zhonglan No.1 was 1.22 cm/d, with a thick albumen content of 19.58%. Fields, Alfaking, Multifoliator and Zhonglan No.1 were the best varieties. These nine American alfalfas can be cultivated in arid areas, loess altiplano semi-arid areas, and semi-humid areas. They can also be used in homologous areas in the north of China.

Effects of different additives on the quality of Medicago sativa silage

MA Chun-hui, XIA Yan-jun, HAN Jun, QIAN Wen-xi, ZHANG Ling, XI Lin-qiao, FANG Lei

2010, 19(1):  128-133. 

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A comparison of M. sativa silage supplemented with crude yeast powder, previously fermented juice, Jingzhunpai additive, or EM-dope and water (CK) was studied at Tarim University from 2006 to 2008. The quality of the silage was improved by all four kinds of additives. The M. sativa forages fermented by crude yeast powder (CYD) and previously fermented juice (PFJ) were valued as excellent and its pH (4.1-4.3), butyric acid, NDF and ADF were the lower than those of the CK. However the lactic acid and ammonium nitrogen contents of the silages fermented by CYD and Jingzhunpai additives were the highest and the lowest, respectively(P<0.05). The crude yeast powder additive was the best by comparison with the CK, with an increased lactic acid content (P<0.05), but significantly (P<0.05) reduced ammonium nitrogen, pH value, acetic acid, propionic acid, butyric acid, neutral detergent fiber, and acid detergent fiber. In conclusion, the quality of M. sativa silages made with CYD and PFJ were equally good and were better than those made with the other additives.

Yield, hay quality and regrowth of establishing Medicago sativa under four harvest schedules

QI Zhi-qiang, YU Yong-xiong, ZENG Zhao-hai, HU Yue-gao

2010, 19(1):  134-142. 

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Harvest schedule is the key point of Medicago sativa production management. This study measured the response of M. sativa yield, hay quality, regrowth, and persistence to four harvest schedules of three cultivars potted in an appropriate growth environment. A high cutting frequency (20 days) reduced M. sativa productivity and persistence but stem densities and regrowth ability recovered after a prolonged cutting interval, although they did not reach the same level as those under a proper cutting schedule. There were considerable differences in M. sativa growth stage, cut resistance, regrowth, yield distribution, and feed value of the three cultivars, which resulted in differences of yield, quality and persistence under the same cut frequency. Two foreign M. sativa cultivars, ‘Vector’ and ‘Durango’, which have high fall dormancy grades, should be cut at intervals of 25-35 days for establishing stands, while M. sativa ‘Gongnong No.1’ (which was bred in the North-East of China) was best suited to a cut schedule of 35-45 days.

A study on morphological variation of germplasm resourcesof Ophipogon japonicus in the Sichuan basin

LIU Jiang, CHEN Xing-fu, YANG Wen-yu, WEN Jun, YANG Xia, CHEN Jia, WANG Feng

2010, 19(1):  143-150. 

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Morphological variation of germplasm resources of Ophipogon japonicus in the Sichuan basin was studied. There were extensive variations in morphology with the most significant variance in fresh root weight, dry root weight, fresh leaf weight, and dry leaf weight. The least significant variance lay in root length and leaf length. Morphological characteristics of O. japonicus have significant relationships. The results of principal component analysis and cluster analysis showed that the first principal component reflected characteristics of plant quantity, the second principal component reflected characteristics of stem leaf, and the third principal component reflected characteristics of earthnut. All of these were main factors resulting in morphological variation of O. japonicus. Cluster analysis based on the morphological characters showed that the 26 germplasm resources of O. japonicus in the Sichuan basin could be divided into four types. The different principal components among the types of O. japonicus were obvious and it is possible to select specific samples from the wide resources of wild O. japonicus according to the different needs of development and utilization.

Kinetic study on cell wall components for brittleness mutation rice at different growth stages

SU Yan-jing, ZHAO Guo-qi, WANG Xiao-shan, YAN Chang-jie, LV Zhong-you

2010, 19(1):  151-157. 

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The kinetic changes of cell wall components between brittleness mutation (BM) rice [Obtained by gamma-ray (γ) treatment] for seeds and its wild type from japonica variety Zhonghua-11 was investigated. 1) BM-rice stem and leaves had brittle and fragile characters in all growth stages. 2) For wild type rice, cellulose content increased during vegetative growth, and then decreased during reproductive growth. Hemi-cellulose content was not changed significantly in the forward process, but decreased drastically in the backward process. For BM-rice, cellulose content was increased gradually over the whole life of the plant. Hemi-cellulose content showed a decreasing trend, but this was not significant between the growth stages. 3) At the tillering stage, the cellulose content of BM-rice stem, leaf and sheath significantly decreased (P<0.01) by 34.69%, 25.89% and 28.85%, respectively compared with that of wild type but the corresponding hemi-cellulose content significantly increased (P<0.01) by 15.77%, 31.31% and 19.32%, respectively. At the heading stage, the cellulose content of BM-rice stem, leaf and sheath significantly decreased (P<0.01) by 32.31%, 32.25% and 34.69%, respectively and the hemi-cellulose content significantly decreased (P<0.01) by 25.39%, 32.78% and 20.91%, respectively. At maturation, BM-rice and CK-rice cellulose content were not significantly (P>0.05) different, but hemi-cellulose contents of BM-rice stem, leaf and sheath were significantly higher than those of the CK-rice. Above all, BM-rice has a potential advantage for utilization as a fodder-rice.

Effects of fresh alfalfa forage on the dressing performance and meat quality of Boer goat

Effects of fresh alfalfa forage on the dressing performance and meat quality of Boer goatLIU Quan-wei, WANG Cheng-zhang, YAN Xue-bing, HE Yun, WANG Yan-hua(School of Animal Science and Vetinary of Henan Agricultural University, Zhengzhou 450002, China)

2010, 19(1):  158-165. 

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Forty-five 3-month-old and weighed [(18.00±1.01) kg] Boer goats were placed into five treatments. Goats were fed diets with 0%, 15%, 30%, 45% or 60% fresh alfalfa during the experimental period. Three healthy male lambs (aged 6 months) from each group, were slaughtered to study the effects of fresh alfalfa on carcass and meat quality. 1) Carcass weight (kg), dressing percentage (%) and lean meat percentage (%) of trialed groups are higher than those of the control group, although there was no marked difference with higher values in groupsⅠand Ⅱ. 2) The lowest pH values of breast meat (P<0.01), shear force, muscle fibre diameter and stearic acid content (P<0.05), as well as highest values of crude fatty acid, protein, linolenic acid (P<0.01) and linoleic acid (P<0.05) contents, were in group Ⅱ. The highest and the lowest values of physical and chemical traits were in the control group. 3) SOD content of group Ⅱ was highest and MDA content was lowest: The opposite to the control group. Fresh alfalfa forage not only reduced the characteristic smell of mutton, but increased its flavour and antioxidant activity. The optimal ratio of adding fresh alfalfa forage to the ration of Boer goat was 30%.

Effects of condensed tannin of Onobrychis viciaefolia hay on the rumen metabolismand in situ degradation of diets by sheep

ZHANG Xiao-qing, HAO Zheng-li, LI Fa-di, ZHENG Chen, JIN Yan-mei, WU Qiu-jue, LI Yong

2010, 19(1):  166-172. 

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Three, one and a half years old, High Mountain Fine-wool wethers with an average weight of 24 kg, were fitted with permanent rumen fistulas. They received a random sequence of three treatments in a 3×3 Latin square design with feeding cycles of 19 days (10 d preliminary period and 9 d sampling period) to study the effect of condensed tannin of Onobrychis viciaefolia hay on rumen metabolism. Condensed tannin (CT) contents in treatmentsⅠ, Ⅱ and Ⅲ were 0.00, 1.52, and 3.03 g/kg of DM, respectively. Three similar sheep were used to measure in situ degradation of DM and CP of three diets. 1) The average rumen pH values of the three treatments were 6.24±0.32, 6.13±0.28, and 6.13±0.37 respectively, and were not significantly different. 2) The ruminal concentration of total VFA tended to increase with the tannin content (P=0.099). Molar proportions of acetic acid were lower (P＜0.05, P=0.074) while those of propionic acid were higher (P=0.088) in treatment Ⅲ than treatmentsⅠandⅡ, and the A/P was lower (P=0.096). 3) The ruminal total N, protein-N, bacteria-N, NH₃-N and urea-N concentration were not significantly (P＞0.05) different. Cellulolytic microbial activity was restrained to a certain extent by 3.03 g CT /kg of DM from O. viciaefolia hay in the diet but amylolytic microbial activity in the rumen was increased.

Genetic diversity of wild Elymus sibiricus germplasm from the Qinghai-TibetanPlateau in China detected by SRAP markers

YAN Jia-jun, BAI Shi-qie, ZHANG Xin-quan, YOU Ming-hong, ZHANG Chang-bing, LI Da-xu, ZENG Yi

2010, 19(1):  173-183. 

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Sequence-related amplified polymorphism (SRAP) molecular markers were used to detect the genetic diversity of 52 wild accessions of Elymus sibiricus collected from the Qinghai-Tibetan plateau. 1) A total 318 fragments were identified with 16 SRAP primer sets and 86.48% were polymorphic. The Nei’s genetic similarity coefficient of the tested accessions ranged from 0.506 4 to 0.958 6, and the average Nei’s coefficient was 0.792 1. The Nei’s index of diversity at the species level was 0.227 0. There was rich genetic diversity among the tested wild resources of E. sibiricus. 2) The results demonstrated a strong geographic effect on molecular variation of the local E. sibiricus as indicated by unweighted pairwise groups method using arithmetic average (UPGMA), and 52 wild accessions were clustered into five groups at GS=0.80 level on a dendrogram. 3) Genetic differentiation between and within five eco-geographical groups of E. sibiricus were estimated by Shannon’s diversity index, which showed that 65.29% genetic variance existed within groups, and 34.71% between groups. 4) Based on Nei’s unbiased measures of genetic identity, UPGMA cluster analysis measures of five eco-geographical groups of E. sibiricus, indicated that there was a correlation between genetic differentiation and eco-geographical habits among the groups.

Polyploid induction and identification of Oncidium

CUI Guang-rong, ZHANG Zi-xue, ZHANG Cong-yu, HU Neng-bing, SUI Yi-hu, LI Jie-qin

2010, 19(1):  184-190. 

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The thin cell layers (TCLs) of protocorm like-bodies (PLBs) of Oncidium were used as explants for polyploid induction with colchicines in vitro. The technical system for ployploid chemical induction of Oncidium in vitro was established. The effects of different concentrations of colchicine induction on PLB formation and shoot regeneration from TCLs of Oncidium after different time treatments were investigated. Morphological and histological characters of lower epidermal cells of polyploid plantlet leaves were compared with diploid ones. Chromosomes of root tip cells of polyploid plantlets were identified. Colchicines greatly affected PLB formation and shoot regeneration from TCLs of Oncidium in vitro. The rate at which TCLs formed PLBs and the numbers of shoots were reduced, but the rate of polyploid plantlet production was higher in the treatments with higher concentrations of colchicines for longer times. Polyploid plants were short and stout with thick leaves. There were some differences in the structure of lower epidermal tissue and cell and stomata of diploid and polyploidy plantlets. The nuclei of polyploid cells were bigger and the number of chromosomes was doubled.

A study on accurate, sustainable, control technology for plateau pika (Ochtona curzoniae)
-Comparative experiment on several rodenticides

WANG Xing-tang, HUA Li-min, SU Jun-hu, CAO Hui, QI Xiao-mei, WANG Jun-mei, LIU Rong-tang

2010, 19(1):  191-200. 

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During April and May 2007, a rodenticide experiment was conducted on control of plateau pika in Sunan, Gansu province. Recommended drug densities and drug values of five rodenticides were adjusted by geometrically increased and decreased values using an orthogonal design. There were differences between recommended values, actual drug densities, drug consumption, bait types, and of adjusted values and types in killing efficiency on plateau pika in the test region. Primary and secondary factors affected killing efficiency and tended to decrease in the order rodenticide types＞drug densities＞bait consumption＞bait types. Five kinds of tested rodenticides were in the order Talon (83.9%)＞Botulin type D (82.6%)＞Bromadiolone (79.4%)＞Botulin type C (75.0%)＞Diphacinone sodium salt (68.9%) according to the assessment index based on control effect. The three optimum treatment combinations were 0.15% Botulin type D, wheat bait, 25 grains bait; 0.01% Talon, naked barley bait, 5 g bait; 0.01% Bromadiolone, wheat bait, 3 g bait.

Spatial and temporal dynamic changes of net primary product basedon MODIS vegetation index in Gannan grassland

WANG Ying, XIA Wen-tao, LIANG Tian-gang, WANG Chao

2010, 19(1):  201-210. 

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Dry matter yield information from field surveying quadrats and MODIS vegetation index data in Gannan Prefecture during 2006-2007 were used to construct a remote sensing monitoring model for aboveground dry matter biomass of grassland. The net primary product (NPP) of grassland was estimated and used to, complete the spatial distribution maps of annual NPP accumulation and monthly NPP dynamic changes, and to evaluate the NPP difference between various grassland vegetation types. The annual maximum NPP of grassland in Gannan Prefecture during 2006-2008 were 637.04, 599.98 and 566.59 g C/(m²·a), respectively. The distribution of annual maximum NPP has a trend of gradual reduction from southwest to northeast and the yearly maximum NPP accumulation of all grassland types was in July and August. The three grassland types with the highest NPP accumulation were marsh, alpine shrub meadow, and alpine meadow, with monthly maximum NPP values of 1 137.28, 553.76 and 527.66 g C/m², respectively (mean values for the three years). The grassland NPP in Gannan Prefecture was continuously decreasing over the three years, with an annual reduction forthe total grassland of 1.2 Tg/a. The reduction of marsh NPP is especially significant, with an annual rate of 125.92 g C/(m²·a).

Dynamic monitoring of grassland production in Hebei

XU Min-yun, LI Yun-qi, XIE Fan, Wang Kun, YU Hai-liang, JING Fu-jun, LI Lian-shu, LI Jia-xiang, LI Xue-feng

2010, 19(1):  211-218. 

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Open-air survey data of 990 quadrats from 110 plots in a Hebei grassland survey from 2005 to 2007 were combined with similar survey data from 1979 to 1984 to compare grassland production and relative changes between 2005-2007 and 1979-1984. 1) Annual total yield of fresh grass from 2005 to 2007 was 62 254 697.81 tons, with an average yield of 13 134.57 kg/hm². Total hay output of the grasslands in Hebei province amounted to 19 438 911.94 tons, with an average yield of 4 101.24 kg/hm²; 2) Grassland production (hay output) of warm temperate shrub-grassland reached 5 133.35 kg/hm², and was the highest among all the steppe types, followed by warm temperate tussock (4 182.22 kg/hm²), marsh grassland (3 376.13 kg/hm²), mountain meadow (in Bashang plateau district, 3 268.35 kg/hm²), temperate meadow-steppe (2 665.94 kg/hm²), mountain meadow (in mountain and hilly areas, 2 111.55 kg/hm²), lowland meadow (1 872.44 kg/hm²), and temperate steppe (1 103.29 kg/hm²). The three steppes types with the largest hay production were: Warm temperate shrub-grassland, arm temperate tussock, and mountain meadow, with production accounting for 56.04%, 20.85%, 18.13% of Hebei production respectively. 3) The average yield of hay production in Hebei province by administrative districts was: Cangzhou(7 134.40 kg/hm²)＞Baoding (6 981.15 kg/hm²)＞Chengde (4 850.26 kg/hm²)＞Shijiazhuang (4 677.78 kg/hm²)＞Handan (2 802.83 kg/hm²)＞Zhangjiakou (2 519.58 kg/hm²)＞Xingtai (2 436.47 kg/hm²)＞Qinghuangdao (2 227.55 kg/hm²)＞Tangshan (1 984.14 kg/hm²). Total hay output of the grasslands in Chengde, Zhangjiakou and Baoding accounted for 84.44% the hay yield of Hebei, while hay yield of the other six administrative regions accounted for only 15.56%. 4) Compared with that of 1979-1984, the average hay yield of 2005-2007 was 36.49% less, with an annual decrease of 1.46%. The average hay output of mountain meadow, temperate steppe, marsh grassland, lowland meadow and temperate meadow-steppe was seriously reduced with a reduction of more than 50%. The relative rate of change of average hay production (R) between 2005-2007 and 1979-1984 of warm temperate shrub-grassland and warm temperate tussock declined range from -5% to -50%, indicating a significant yield reduction grade. The grassland hay area yield reduction accounted for 91.96% of the Hebei grasslands, with 31.92% of the area production seriously reduced with the extent of reduction >50%, while 8.04% of the grassland remains unchanged compared to that in 1979-1984.

Biodiversity, ecosystem functioning and spatio-temporal scales

JIANG Xiao-lei, YUE Jing, ZHANG Wei-guo, LIU Bin

2010, 19(1):  219-225. 

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The relationship between biodiversity and ecosystem functioning has emerged as a central issue in ecology. A number of researchers have shown that diversity has an important influence on ecosystem functioning, including productivity, decomposition, nutrient cycling, and stability. A review of a great deal of scientific literature on relationship patterns, mechanisms, ongoing debate between initial components of biodiversity-species diversity, on two ecosystem functioning-productivity and invasibility, and on the effects of spatio-temporal scales is summarized. Through basic theoretical synthesizing, the relationship between diversity and productivity, invasibility, along with the mechanisms controlling them were elucidated. This review will provide a valuable reference source for research and will promote biodiversity research in China.

Advances in the research of heterostyly

CHEN Ming-lin, YOU Ya-li, ZHANG Xiao-ping

2010, 19(1):  226-239. 

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Heterostyly is a genetically controlled floral polymorphism in which plant populations are composed of two (distyly) or three (tristyly) floral morphs. Based on the many references at home and in the world and the own works, the classification, characters, distribution and evolution of heterostylous plants were reviewed in the present paper. At present, the heterostylous plants of 193 genera, oblonging to 30 families, which account for 1%-2% flowering plants, were found. The morphs of heterostylous species differ reciprocally in the heights of stigmas and anthers in flowers, accompanied with ancillary morphological polymorphisms involving the number and size of pollen, the color and size of anther, the shape of style, the height, density, and distribution of papillae. Heterostylous plants always have physiological self- and intra- incompatibility system, but under certain circumstances, they present fertility at different level. Heterostyly seems to have evolved in different directions, one towards dioecy or subdioecy, another towards agamospermy, and the third towards homostyly and self-fertility. Heterostyly was now considered to limit functional interference between sexual organs and avoid self-pollination. Combining molecular technologies and ecological methods, wild observations and biological statistics are still the important job in the future. Studies on heterostyly could provide purviews and inspiration for plant reproduction, development and evolution, the conservation and utilization for the rare and endangerded plant resources, as well as the coevolution between plants and animals.

Research advances in the eco-physiological characteristics of ephemerals adaptation to habitats

YUAN Su-fen, TANG Hai-ping

2010, 19(1):  240-247. 

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Ephemerals are specially adapted to desert grasslands, Mediterranean grasslands, and the floor of deciduous, broad-leaved temperate forests conditions. They are considered to be a special herbaceous population that can take advantage of water resources and temperature conditions to rapidly complete their life-circle within two or three months. They mainly occur in arid or semi-arid areas, such as North America, Africa, Mediterranean areas, Western and Central Asia and partial zones of mid-Asia. Previous studies focused on their taxonomy and flora. Their adaptations to growing environmental conditions have not received enough attention, nevertheless, most aspects of adaptations to habitats are included in current studies although they are short of lateral comparison and systematic summarization. This paper reviews current research on the adaptations and feedback of ephemerals to light, temperature, water in environment, etc. Ephemerals have strong adaptability to habitats, and form their characteristic morphology, behavior and eco-physiology adaptations during a long-term process of acclimatization. In many extreme surroundings, ephemerals, as pioneer plants, play an important role in modifying soil texture and water content to provide new plants with a chance of successful invasion under improved environmental conditions. Ephemerals can act as a “Vernal Dam” by absorbing many nutrient elements on their surface and by promoting sound soil nutrient cycling. Ephemerals have higher photosynthetic rates and biomass in desert communities. They are important primary producers that may be important for the carbon pool. Finally, from the research summary and conclusions of the above dissertation, we discuss prospective future research directions. This paper can provide readers with a comprehensive understanding of ephemerals and their adaptation to environments, and supply concepts and references for further research.

Analysis on variance and correlation of mainly shrub nutrients on karst areas in Southwest Guizhou

HUANG Fen, CAO Jian-hua, LIANG Jian-hong, HE Yuan-yuan, ZHU Min-jie

2010, 19(1):  248-252. 

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Six nutrient contents of 3 families with 19 genera and 27 species of fodder shrubs were measured in order to select suitable fodder shrubs to grow in the karst areas in Southwest Guizhou. And thereby promote the development of local animal husbandry and increase the income of farmers, then dates are made quantitative and correlation analysis. 1) Indigofera pseudotinctoria and Broussonetia kazinoki meet the requirements of a typical protein feed. 2) Mean values of ASH and NFE showed extremely significant difference among three families: The Moraceae had significantly higher ASH content than the other two families. The Leguminosea had significant lower NFE content than the Moraceae and Rosaceae; 3) There were high negative correlation coefficients between CF and NFE,EE,CP,and ASH,so the CF content strongly affects the overall nutritional value of fodder shrubs.

Influence of three disinfectants on germination and seedling growth of Cichorium intybus

ZHANG Yu, LI Cong, BAI Shi-qie, WANG Yong-xin, LI Da-xu

2010, 19(1):  253-257. 

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Effects of 3 disinfectants(1∶150 84, 0.1% HgCl₂ and 10% H₂O₂) and 3 times on rate of germination, contamination and growth index(GI) of Cichorium intybus were researched with orthogonal design and influence on seedling of C. intybus cv. puna. All factors had the most significant effects on germination; disinfectants and sterilizing time had more significant effects on contamination frequency and germination index of C. intybus, but varieties of C. intybus is not significant frequency. 0.1% HgCl₂ had the most significant disincentive effect to C. intybus cv. puna. Above all the best method of building aseptic plant of C. intybus is 10% H₂O₂ immersing 10 min.

Analysis on different populations of Cynodon dactylon by RAPD

LIANG Hui-min

2010, 19(1):  258-262. 

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Genetic differences of 28 Cynodon dactylon populations were examined by RAPD and morphological observation. Using 20 ologonucleotide primers, 326 bands were obtained of which 314 (96.32%) were polymorphic, an average of 15.7 per primer. A complicated genetic background and abundant genetic diversity were found in the experimental germplasms. According to cluster and morphological analysis, the 28 C. dactylon populations could be classified into three types of which type A (12 populations) had a genetic similarity coefficient ranging between 0.251 0 and 0.054 1. The comparative genetic differences of this type were larger with more abundant polymorphisms than the other types. The leaves of type A were long and wide with a hard texture. This type included germplasms from Guangzhou, Zhejiang, Wuxi, Nanjing, Qingdao. Type B involved 9 populations with a genetic similarity coefficient of 0.233 9-0.121 6. The genetic difference was less and genetic relationship closer than in type A. The leaves were shorter and the texture finer. Type B included varieties introduced from other cities and other countries. Type C consisted of 7 populations collected from interland regions of Shandong province. They had a genetic similarity coefficient of 0.500-0.143 showing a large genetic difference.

Research on screening of Stylosanthes mutants with enhanced chilling resistanceby a combination of DES mutagenesis and in vitro selection

WANG Xiao-hua, ZHUANG Nan-sheng, WANG Ying, GAO He-qiong, HAN Ping-yuan

2010, 19(1):  263-267. 

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Cut cotyledons of Stylosanthes guianensis cv. Reyan 2 seedling plants were used for explant production based on in vitro callus multiplication techniques. DES mutagenesis was applied under different temperatures in combination with in vitro selection on L-Hyp containing medium for induced callus production. The survivors from this 2 step in vitro selection of L-Hyp to plantlets, were subjected to 1℃-8 d low temperature selection, and the plantlets were then classified according to chilling injury into 4 grades. Randomly selected two plantlets with the lowest level of chilling injury (1^st chilling injury), were taken at random and part of the stems were cut off for callus induction. These calluses were tested for physiological indices of cold resistance. The survival rate of calluses treated at the lowest temperatures was higher under the same concentrations of DES. Treatment with 0.4% DES (10℃, 2 h) for callus had the best survival rate (18.6%),which was significantly better than the 6.6% of the CK. Fourteen plantlets of the 1^st chilling injury were obtained from those that survived the 2 step in vitro selection of L-Hyp after low temperature selection, while there were no surviving plantlets from the CK. The 1^st chilling injury plantlets had a significantly better cold tolerance than those from the CK.