Physiological process is essential for plant growth, and is sensitive to environmental change. The Minjiang River dry valley in the upper reaches of the Yangtze River is increasing as it is affected by human activity, environmental changes, and their interactions under global climate change scenarios. Water deficit is a major limiting factor in vegetation recovery in this region. Therefore, evaluation of the physiological and biochemical levels is important to determine drought stress adaptations in plants and the selection of drought-tolerant plants. The aim of this study was to investigate the adaptation mechanisms of selected shrubs to drought stress in the Minjiang River dry valley, and to provide a reference for selecting drought-tolerant shrubs. We selected six mountain shrubs from this region, including Hippophae rhamnoides, Bauhinia faberi, Sorphora davidii, Caragana arborescens, Berberis sargentiana , and Cotinus szechuanensis . We evaluated changes of anti-oxidant protective enzyme activities, membrane injury indexes, and osmotic adjustment substances in leaves of these shrubs subjected to increasingly severe drought conditions, using pot experiments. The results showed that the responses of different anti-oxidant protective enzymes of these shrubs to drought stress and subsequent oxidative stress were different. In all six shrubs, superoxide dismutase (SOD) activities first increased and then decreased with prolonged drought stress, peroxidase (POD) activities increased gradually as drought stress continued, whereas catalase (CAT) activities increased in the middle and late stages of drought stress, indicating various protective enzymes could be playing inter-coordinating roles at different stress stages. Malondialdehyde (MDA) in all shrubs showed a slow increase with the prolonged drought stress, indicating that the membrane lipid peroxidation of cells gradually increased, and plants began to experience toxicity. With prolonged drought stress, the membrane permeability of H. rhamnoides and B. faberi initially increased, then decreased, and finally returned to the initial level at the end of the stress period, probably because these two shrubs obtained drought resistance by drought hardening. Membrane permeability of S. davidii and C. szechuanensis remained unchanged between 0 and 4 days when exposed to drought stress, and then sharply increased after 8 days, and then was maintained at a relatively high level. These findings implied that the membrane structure and function of these two plants was still intact and physiological activities could still proceed normally at early stages of drought stress; however, the cell membranes suffered serious damage during the middle stages of drought stress. In all six shrubs, proline contents increased with increased drought stress, indicating that drought stress resulted in proline accumulation and thus improved cell osmotic adjustment capabilities. Principal component analysis can provide a quantitative evaluation of the different physiological and biochemical indexes for the seedlings under drought, which indicated that the six shrubs could be ranked from the most to least drought resistant as follows: B. faberi, H. rhamnoides, C. arborescens, C. szechuanensis, S. davidii, B. sargentiana . The study revealed that all six shrubs positively responded to drought stress through improved antioxidant enzyme activity and the accumulation of osmotic adjustment substances, which could help to reduce reactive oxygen injury, improve osmotic adjustment capabilities, and reduce cell damage.

以岷江干旱河谷区6种典型山地灌木[沙棘（ Hippophae rhamnoides ）、羊蹄甲（ Bauhinia faberi ）、白刺花（ Sorphora davidii ）、锦鸡儿（ Caragana arborescens ）、三颗针（ Berberis sargentiana ）、黄栌（ Cotinus szechuanensis ）]为试材，采用盆栽试验研究了土壤自然干旱胁迫对苗木叶片抗氧化保护酶活性、膜伤害程度以及渗透调节物质的影响，探讨植物应对土壤干旱逐渐加剧的生理生态适应机理。结果表明，植物不同抗氧化保护酶对干旱胁迫及随之而来的氧化胁迫的响应存在一定差异。各灌木的超氧化物歧化酶随着干旱胁迫的增强呈先上升后下降，过氧化物酶在整个胁迫期间表现为逐渐升高，过氧化氢酶的升高则主要发生在胁迫的中后期，表明不同胁迫时期对植物体起主导作用的保护酶不同，三者表现为相互协调的作用方式。随着干旱胁迫的增强，各灌木的丙二醛呈缓慢增加趋势，细胞的膜脂过氧化作用逐渐加强，植物开始遭受一定程度的毒害。沙棘和羊蹄甲叶片的质膜相对透性随胁迫的增强呈现先升后降最终回到初始水平的特点，表明植物可以通过干旱锻炼获得一定的抗旱能力。白刺花和黄栌叶片的质膜相对透性在胁迫的0-4 d保持不变，从8 d开始大幅上升并一直维持在较高水平，说明胁迫初期植物细胞膜的结构和功能还很完整，生理活动仍能正常进行，但从中期开始细胞膜遭受严重破坏。随着干旱胁迫的增强，各灌木叶片的脯氨酸总体均呈增加趋势，表明干旱胁迫下植物通过积累脯氨酸以提高细胞的渗透调节能力。主成分分析表明，6种灌木的抗旱能力由强到弱依次为：羊蹄甲、沙棘、锦鸡儿、黄栌、白刺花、三颗针。综合分析表明，干旱河谷区几种典型灌木可通过提高抗氧化酶活性并积累渗透调节物质对干旱胁迫进行积极的反馈，以减弱逆境胁迫下活性氧的危害，提高细胞的渗透调节能力，减轻细胞遭受的损伤。

In order to enhance production of potato as pillar industry in arid and semi-arid areas of Ningxia, and find a new way to solve drought and water shortage, especially at seedling stage of potato growth process, a field study was conducted to determine effects of super absorbent dosages on soil physical properties of dryland and potato yield by using two dosages of super absorbents (Wote and Microbe). The results showed that, the soil bulk density of the 0 to 30 cm depth was significantly decreased by 9.0% compared with no aquasorbent applying (CK) under using Wote super absorbent for 90 kg·hm -2 , but it greatly improved total soil porosity of the 30 to 60 cm depth by 8.9% with using Microbe super absorbent for 90 kg·hm -2 . The Microbe super absorbent treatments produced higher amounts of>0.25-mm macroaggregates compared with CK at the 0 to 30 cm depth. In contrast, the Wote super absorbent treatments produced higher amounts of>0.25-mm microaggregates at the 30 to 60 cm depth. The super absorbent treatments obviously increased the amount of soil water stored at the 0 to 100 cm depth during the critical growing stage of potato, and the Microbe super absorbent treatments improved soil water status best at early stage of potato. However, the Wote super absorbent treatments could significantly improve soil water status at expansion-maturity stage. Higher yield improvements were achieved with using two dosages of super absorbents compared with CK. The yield of potato was increased by 41.1% with using Wote super absorbent for 60 to 90 kg·hm -2 , and the commodity rate improvements was 21.1% with using Wote super absorbent 60 to 90 kg·hm -2 , when compared with no aquasorbent applying respectively. This study could provide some reference for rational application of super absorbent in potato production in dry farming region of Ningxia.

为促进宁夏干旱半干旱区马铃薯支柱产业的发展,解决马铃薯生产,特别是苗期干旱缺水等问题,以2种土壤保水剂(沃特保水剂和微生物保水剂)为对象,研究了不同保水剂施用量对旱作土壤物理性状及马铃薯产量的影响.结果表明,相对于不施保水剂处理(对照),2种保水剂均可有效降低土壤容重,改善土壤孔隙结构,穴施沃特保水剂90 kg·hm -2 的0~30 cm土层土壤容重显著降低9.0%,穴施微生物保水剂90 kg·hm -2 的30~60 cm土层土壤孔隙度显著增加8.9%.施用微生物保水剂各处理使0~30 cm土层>0.25 mm机械稳定性团聚体数量均较对照显著提高,施沃特保水剂各处理使30~60 cm土层>0.25 mm团聚体数量较对照显著提高.在马铃薯关键生育期,施用微生物保水剂可改善马铃薯生育前期0~100 cm土层土壤贮水量,而施用沃特保水剂可提高马铃薯生育中后期土壤水分状况.2种保水剂处理下,马铃薯产量均显著高于对照,其中穴施沃特保水剂60~90 kg·hm -2 的增产效果最佳(41.4%),商品薯率最高(21.1%).该研究可为宁夏旱作区马铃薯合理施用保水剂提供参考.

The effects of 5 different kinds of water retentive agents at 2 application levels on yield, water use efficiency and root morphology of winter wheat were studied through field experiments. The results showed that there were significant differences in tiller number, flag leaf area, yield and water use efficiency (WUE) among the water retentive agent treatments of different varieties and application levels. Compared with the control, the yield increased by 1.3%-7.9%, and the WUE increased from 17.1 kg·hm -2 ·mm -1  to 18.0-20.7 kg·hm -2 ·mm -1  under these 5 different kinds of water retentive agent treatments. The influences of water retentive agents on average root diameter, total root length and total root surface of winter wheat all reached a significant level. The total root length increased by 3.7%-19.1% and 6.3%-27.3%, and the total root surface area increased by 6.5%-21.7% and 2.9%-18.5% in the 0-20 and 20-40 cm soil layers, respectively. The root morphology characteristics were significantly positively correlated with both yield and WUE of winter wheat. The compound water retentive agent of acrylamide/inorganic mineral had the most significant influence on the increase of WUE and the promotion of root growth of winter wheat.  

采用田间小区试验，研究5种不同类型保水剂及2个施用水平对冬小麦产量、水分利用效率、根形态的影响.结果表明: 冬小麦茎蘖数、旗叶面积、产量和水分利用效率在不同类型保水剂及施用量处理之间存在显著差异.与对照相比,5种保水剂处理冬小麦产量增加1.3%～7.9%,水分利用效率由对照的17.1 kg·hm -2 ·mm -1 提高到18.0～20.7 kg·hm -2 ·mm -1 .保水剂对冬小麦根系的平均直径、总根长和总表面积的影响均达到显著水平,在0～20和20～40 cm土层,总根长分别增加3.7%～19.1%和6.3%～27.3%,总表面积分别增加6.5%～21.7%和2.9%～18.5%.冬小麦根系形态特征与冬小麦产量和水分利用效率均呈显著正相关.丙烯酰胺/无机矿物复合型保水剂对提高冬小麦水分利用效率和促进根系生长效果最为明显.

Seven main agronomic traits, eight physiological indices and yield index of 15 main flax cultivars in China were measured during maturity under the conditions of irrigation and natural rainfall. Comprehensive drought resistance coefficient (CDC value), factor analysis, subordinate function coefficients, clustering analysis, grey relational analysis were used to evaluate the drought resistance, classify drought resistance type and select evaluation indices in tested flax cultivars. The response to drought stress and correlations of tested traits and indices were different. Yield and photosynthesis factors as well as leaf antioxidant factors were closely associated with drought resistance, so could be used as priority indicator of drought resistance evaluation. Factor analysis showed that six common factors could represent 90.89% of the original information of flax drought resistance data. The ranks of drought resistance of tested flax cultivars based on drought resistance comprehensive evaluation values (D value) and weight drought resistance coefficient (WDC value) were similar, the drought resistance was the same for six flax cultivars, arranging from the first to third in drought resistance. D values of tested flax cultivars had significant and positive correlation with CDC value, WDC value and Y value. Y values of tested flax cultivars also had very significant and positive correlation with CDC value and WDC value. According to D value clustering analysis, tested cultivars were divided into five grades in drought resistance, reflecting the diffirence of cultivars in breeding condition and adaptive region growing well. Drought resistance evaluated mainly with yield by D value as index and WDC value as auxiliary index in flax were appropriate and accurate. Drought resistance comprehensive evaluation methods can be used in studying exactly drought resistance evaluation, classification of drought resistant type and screening evaluation indices in flax.

以15份国内胡麻栽培品种为材料, 设自然降雨和正常灌水2个处理, 考察与抗旱性相关的7个农艺性状、8个生理生化指标及产量指标, 采用综合抗旱系数、因子分析、隶属函数、 聚类分析和灰色关联度分析相结合的方法 , 对其抗旱性进行综合评价、抗旱型划分和评价指标筛选。结果显示, 相关性状 指标对干旱胁迫的反应及关联程度各异 , 可优先选择与抗旱性关系密切的产量及其相关性状、光合作用因子、叶片抗氧化因子等相关生理生化性状；因子分析表明, 6个公因子可代表胡麻抗旱性90.89%的原始数据信息量。基于抗旱性度量值(drought resistance comprehensive evaluation values, D值)和加权抗旱系数( weight drought resistance coefficient, WDC 值)的各品种抗旱性排序相近, 位居前6位的抗旱品种相同。各品种D值与综合抗旱系数( comprehensive drought resistance coefficient, CDC 值)、WDC值、产量抗旱系数(yield drought resistance coefficient, Y 值)之间均呈极显著正相关, 而各品种Y值与CDC、WDC值间极显著正相关；据D值将供试品种划分为5个抗旱级别, 可较好地反映品种的选育条件及适应地区。试验结果说明以D值为主要参数, 以WDC为辅助评价参数, 评价以产量为主要考量目标的胡麻抗旱性是适宜且准确的；以抗旱性综合评价方法进行胡麻抗旱性综合评价、抗旱型划分、评价指标筛选是准确的。

以一年生梭梭移栽苗为研究对象，比较了不同浓度的保水剂对土壤水分、梭梭生长特性和根系形态的影响。结果表明，保水剂能够提高土壤含水率，在土壤水分较低时，０．２０％浓度的保水剂显著提高了２０～４０ｃｍ 土壤含水率；土壤水分较高的４－６月，０．０５％浓度的保水剂对梭梭同化枝生长促进显著，土壤水分较低的７－９ 月，０．２０％浓度促进最显著；０．２０％浓度的保水剂显著提高了梭梭的株高、冠幅、新生枝长、基径；０．０５％和０．２０％浓度的保水剂显著提高了梭梭的总表面积和总根长，总表面积较对照分别增加６４．６５％和１２５．６２％，总根长分别增加８１．６８％和１３０．９２％。综上，在土壤水分较高的４－６月，最适宜梭梭生长的保水剂浓度为０．０５％，在土壤水分较低的７－９月，０．２０％浓度的保水剂促进显著。

With the purpose of promoting water-saving irrigation and cotton yield in Xinjiang Uyghur Autonomous Region, the effect of super absorbent polymer (SAP) on the growth, dry matter accumulation and distribution, water absorption and yield of cotton were studied through field experiments. The results showed that SAP application induced to the reduction in plant height, leaf number of the main stem, square number and leaf area, while an increase in boll numbers. SAP application could accelerate the growth of root, square and boll. The dry matter allocation ratio from nutritional organs to reproductive organs increased by 13.8%–25.8%, and the water transportation ability from roots to stems and leaves was also enhanced. Compared to the usual irrigation quantity of farmers, SAP application could save water 21.1% and increase yield 6.7%–22.0% under proper water-saving irrigation (the irrigation quantity was above 40% of the usual irrigation quantity). When the irrigation quantity was 40% of the usual irrigation quantity, the yields of cotton were not reduced with SAP application. Moreover, the yields could increase 22.0% with SAP application and 7.4% without SAP application, compared to the control (usual irrigation, without SAP application), when the irrigation quantity was about 80% of the usual irrigation quantity, which was considered as the optimal irrigation quantity. The high production of cotton was relative to the increased boll numbers and boll weights, and the regulation of dry matter accumulation, distribution and water metabolism with SAP application.

为指导新疆灌溉棉区棉花节水灌溉和增产，通过大田试验，比较研究5种不同灌溉条件下保水剂对棉花生长、干物质积累与分配、水分吸收及产量的影响。结果表明，施用保水剂能不同程度地抑制棉花株高，使主茎叶数、单株蕾数和叶面积减小，但单株铃数会增加。保水剂能促进棉花根系和蕾铃发育，使干物质由营养器官向生殖器官的分配比增加13.8%～25.8%，同时增强了水分由根系向茎叶的运输能力。适宜减量灌溉（常规灌量的40%以上）条件下，施用保水剂在节水21.1%以上的前提下，仍能较对照（充足灌溉，且无保水剂）增产6.7%～22.0%；即使是以常规灌量的40%进行灌溉，施保水剂也能保障棉花不减产。在该试验条件下，常规灌量的80%为最适灌溉量，能使棉花产量较对照显著提高22.0%（有保水剂）和7.4%（无保水剂）。初步分析认为，引起棉花增产的直接原因是单株铃数和单铃质量增加，间接原因是保水剂调控了不同器官干物质的积累与分配，以及水分代谢状况。