Effects of water stress and NaCl stress on different life cycle stages of the cold desert annual Lachnoloma lehmannii in China

For a plant species to complete its life cycle in arid and saline environments, each stage of the life cycle must be tolerant to the harsh environmental conditions. The aim of the study was to determine the effects of water stress (water potentials of -0.05, -0.16, -0.33, -0.56, -0.85 and -1.21 MPa) and NaCl stress (50, 100, 200, 300, 400, 500 and 600 mmol/L NaCl) on seed germination percentage, seedling survival and growth, juvenile growth and plant reproduction of Lachnoloma lehmannii Bunge (Brassicaceae), an cold desert annual that grows in the Junggar Basin of Xinjiang, China in 2010. Results indicated that low water stress (-0.05 and -0.16 MPa) had no significant effect on seed germination percentage. With a decrease in water potential, germination percentage decreased, and no seeds germinated at -0.85 and -1.21 MPa water stresses. Germination percentage of seeds was significantly affected by NaCl stress, and higher germination percentages were observed under non-saline than saline conditions. An increase in NaCl concentrations progressively inhibited seed germination percentage, and no seeds germinated at ≥400 mmol/L NaCl concentration. Non-germinated seeds were transferred from both PEG (polyethylene glycol-6000) and NaCl solutions to distilled water for seed germination recovery. The number of surviving seedlings and their heights and root lengths significantly decreased as NaCl stress increased. About 30% of the plants survived and produced fruits/seeds at 200 mmol/L NaCl concentration. Thus, seed germination, seedling establishment and reproductive stage in the life cycle of L. lehmannii are water- and salt-tolerant, with seedlings being the least tolerant. These tolerances help explain why this species can survive and produce seeds in arid and saline habitats.     

Evaluation of coastal sandy soils and their saline ground waters for afforestation: A case study from India

A study was conducted in coastal Andhra Pradesh to evaluate current practices and suitability of coastal sandy soils for raising tree plantations. Poor soil moisture retention characteristics of these soils make irrigation an essential, but costly silvicultural practice for obtaining desirable establishment and growth. Saline ground water is the only available source of irrigation. Its use seems safe and successful in such soils. The farmers have adopted a specialized manual splashing technique (Doruvu) of seepage pits for irrigating tree plantations in their establishment phase. This technique was observed to be well suited to the sandy soils. Casuarina equisetifolia and Eucalyptus tereticornis were the two most popular species being afforested. E. camaldulensis is also in an introduction phase. Comparison of growth performance and biomass accumulation by C. equisetifolia and E. tereticornis plantations at different growth stages showed the former to be significantly better than the latter. Build up of the soil organic carbon was also found to be markedly more in comparable C. equisetifolia plantations than those of E. tereticornis. Similarly, the blanketing influence of C. equisetifolia plantations was observed to modify soil temperature extremes considerably more than in the case of E. tereticornis. The findings, indicated a vast scope for utilization of coastal sandy soils for afforestation with the successful use of saline ground waters.     

土壤盐胁迫下杨树次生木质部的解剖特征

对生长在苏北沿海防护林不同土壤盐度下的主栽树种杨树(欧美杨无性系69杨)进行了解剖,描述了杨树次生木质部结构的特征,测量了次生木质部的16个数量特征：年轮宽度(ARW)、导管长度(VL)、早材和晚材的导管分子面积(VA)、导管周长(VP)、导管直径(VD)、导管单孔率(PSV)、导管频率(VF)、纤维长度(FL)、纤维宽度(FW)、射线高度(RH)和射线频率(RF)。实验结果表明,在不同的土壤盐度胁迫下：(1)杨树次生木质部形态特征的差别不明显,但是组成分子趋向于小型化。(2)次生木质部数量特征的变化比较明显,即当土壤含盐量从0．036％逐渐升高到0．289％,杨树的年轮宽度变小,0．91→0．77mm;纤维长度和宽度的变化分别为693．8→570μm和14．9→13．5μm,射线高度和频率的变化分别为284．3→249．2μm和58．9→75．5mm^-2,表明在盐胁迫下杨树的生长受到抑制。随着盐度的增加0．036％→0．289％,杨树导管长度减小,367．6→341．5μm;在早材和晚材中,导管面积变化分别为1575．6→1703．6μm^2和760．1→947．7μm^2,导管周长变化分别为167．7→195．1μm和120．8→143．7μm,导管直径的变化分别为41．8→43．4μm和29．1→33．1μm,导管频率的变化分别为141．8→144．2mm^-2和160→206．7mm^-2;导管单孔率的变化分别为65．9％→30．5％和59．4％→40．8％。这些都表明在盐胁迫下杨树的导管缩短变粗,呈聚集分布,输水效率和输水安全性都有所提高。     

新疆阿其克苏河沿岸地下水水质与主要离子关系研究

通过选取新疆艾比湖湿地国家级自然保护区阿其克苏河东大桥管护站至塌桥子管护站15km为研究区域,野外分两次采样：在研究区内中德合作项目胡杨样地及垂直河道胡杨、柽柳混交林处采挖地下水测点,在典型植被芦苇、梭梭、柽柳及出露的泉水处采挖地下水测点,分别采集水样。实验室实测地下水矿化度及主要离子（K^＋、Na^＋、Ca^2＋、M...     

7种园林植物的耐盐性研究

利用滨海盐碱土配制栽培土壤,采用大棚盆栽试验方法,对7种常见园林绿化植物的生长表现、存活率、高生长、叶绿素含量、相对含水量进行研究的结果表明:连翘、月季和四季桂的耐盐性较差,只能在含盐量不大于2.3 g/kg的土壤中正常生长;其次为金叶女贞,能在含盐量不大于4.6 g/kg的土壤中生长;雪松能在含盐量不大于4.9g/kg的土壤中正常生长;油松能在含盐量不大于5.8g/kg的土壤中正常生长;爬地柏耐盐性最强,能正常生长于含盐量高达8.7g/kg的土壤中.     

滴灌下氮盐交互对加工番茄荧光特性及产量品质的影响

【目的】新疆有着全中国最大面积的盐碱地和加工番茄的种植基地。在新疆开展两年试验以研究加工番茄在氮盐交互下生长、生理、产量和品质的变化规律,获得适宜新疆盐碱地种植加工番茄的合理施氮量和土壤盐分范围,为新疆扩大加工番茄种植面积和合理施氮提供科学的理论依据及技术途径。【方法】试验于2017和2018年在石河子大学现代节水灌溉兵团重点实验基地进行,以当地主栽品种3166为试验材料,2017年试验共设置4个土壤含盐量水平：1.5、4.0、7.0和10.0 g·kg ^-1及4个氮素水平：201、166、131和96 kg·hm ^-2,2018年在2017年的基础上去除10.0 g·kg ^-1的土壤含盐量,增加5.0 g·kg ^-1的土壤含盐量和不施氮量处理。试验测定和分析加工番茄的荧光叶绿素参数、产量和品质指标。【结果】在氮盐交互下,加工番茄荧光参数及产量等指标均呈现出复杂的变化规律。绝大多数的荧光参数及产量受土壤盐分的主导作用较氮素强,在同等氮素水平下,7.0 g·kg ^-1和10.0 g·kg ^-1的土壤盐分对加工番茄荧光指标抑制程度最大;低盐分水平下,166 kg·hm ^-2的中等偏高的施氮量对加工番茄的荧光指标促进作用最大,其次是施氮201 kg·hm ^-2的处理;在中等偏高的盐分水平下,96 kg·hm ^-2的低氮对加工番茄的最好,其次为不施氮水平。加工番茄的鲜果产量总体上符合“盐高产低”的规律,但低氮高盐处理的产量明显高于其他同盐度的氮素水平下的产量。可溶性固形物、VC、可溶性糖和可滴定酸均随着土壤含盐量的增大逐渐增大,糖酸比的最大值均出现在低盐处理,盐分对加工番茄品质的影响远高于氮素,二者交互对加工番茄的品质并无显著性影响。通过图形叠加分析方法,得出了加工番茄获得相对最优产量和品质的合理施氮范围和土壤含盐量区间。【结论】在盐碱程度偏高的土壤可通过少施氮素来提高加工番茄产量;加工番茄获得相对最优产量和品质的合理施氮范围和土壤含盐量区间为N：98.12—119.60 kg·hm ^-2,S：3.57—5.58 g·kg ^-1。     

Redox halopriming: A Promising Strategy for Inducing Salt Tolerance in Bread Wheat

New strategies to enhance growth and productivity of food crops in saline soils represent important research priorities. This study has investigated the role of certain priming techniques to induce salt tolerance of bread wheat. Wheat grains were soaked in 0.2 mm sodium nitroprusside as nitric oxide donor (redox priming), diluted sea water (halopriming) and the combination of both (redox halopriming). Grains were also soaked in distilled water (hydropriming); in addition, untreated grains were taken as control. Our results indicated that priming treatments significantly improved all growth traits and increased leaf pigments concentration as compared to the control. Priming treatments markedly enhanced membrane stability index, proline, total soluble sugars and K⁺ concentration with simultaneous decrease in the concentration of Na⁺ and malondialdehyde (MDA). Furthermore, yield and yield‐related traits such as plant height, spike length, total number of tillers, 1000‐grain weight, straw and grain yield considerably affected by priming treatments. Moreover, the grain yield of both genotypes was positively affected by redox halopriming treatment. However, the extent of enhancement was more prominent in Gemmiza‐9 (salt sensitive) than that in Sakha‐93 (salt‐tolerant). Overall, this study clearly indicated that redox halopriming treatment is a promising and handy technique to induce salinity tolerance of wheat genotypes.     

Comparison of Salt and Drought‐Stress Effects on Maize Growth and Yield Formation with Regard to Acid Invertase Activity in the Kernels

The long‐term effects of salt stress (11 dS m^?1) and drought stress (35 % WHC) were investigated for two maize genotypes, focusing on the relation between metabolic changes around the time of pollination and the impact on yield determinants at maturity. The relatively salt‐resistant hybrid Pioneer 3906 and the relatively drought‐resistant hybrid Fabregas were compared. The experiments were conducted in large plastic containers in a vegetation hall in two consecutive years (2011 and 2012). Plant height and leaf area were significantly reduced under both stress conditions. The transpiration rate was only slightly reduced under drought stress; but under salt stress, a significant reduction occurred 40–53 days after sowing. As a significant increase in sucrose concentrations was observed in the salt‐treated maize kernels 2 days after pollination, the availability of assimilates was not limiting and the plants could afford to save water by reduced stomatal opening. Although under both stress conditions the soluble acid invertase activity was reduced 2 days after pollination, concomitantly, an increase in hexose concentrations was observed. Thus, in these experiments, the delivery of hexoses by acid invertase activity did not limit kernel development. Differences in grain yield at maturity between salt and drought stress were most likely caused by salt‐specific effects (Na⁺ toxicity), Fabregas being more affected than Pioneer 3906.