大豆耐盐性种质的分子标记辅助鉴定及其利用研究

大豆耐盐种质的鉴定对于促进大豆耐盐育种具有重要作用。本文利用已获得的大豆耐盐性基因的共显性PCR标记，对选自于国家作物种质库的59份耐盐和盐敏感种质加以鉴定，同时进行了田间耐盐性重复鉴定，并对种质库耐盐性记载结果、田间耐盐性重复鉴定结果与分子标记鉴定结果进行比较，从中选出田间耐盐性重复鉴定结果与分子标记鉴定结果一致的耐盐种质42份，分析了这些种质间的遗传多样性，为大豆处质资源的改良及耐盐遗传育种中的亲本选配提供了理论依据，同时对分子标记应用于种质鉴定和育种实践进行了有益的尝试。     

OsSUV3 transgenic rice maintains higher endogenous levels of plant hormones that mitigates adverse effects of salinity and sustains crop productivity

Background

The SUV3 (suppressor of Var 3) gene encodes a DNA and RNA helicase, which is localized in the mitochondria. Plant SUV3 has not yet been characterized in detail. However, the Arabidopsis ortholog of SUV3 (AT4G14790) has been shown to be involved in embryo sac development. Previously, we have reported that rice SUV3 functions as DNA and RNA helicase and provides salinity stress tolerance by maintaining photosynthesis and antioxidant machinery. Here, we report further analysis of the transgenic OsSUV3 rice plants under salt stress.

Findings

The transgenic OsSUV3 overexpressing rice T₁ lines showed significantly higher endogenous content of plant hormones viz., gibberellic acid (GA₃), zeatin (Z) and indole-3-acetic acid (IAA) in leaf, stem and root as compared to wild-type (WT), vector control (VC) and antisense (AS) plants under salt (200 mM NaCl) stress condition. A similar trend of endogenous plant hormones profile was also reflected in the T₂ generation of OsSUV3 transgenic rice under defined parameters and stress condition.

Conclusions

In response to stress, OsSUV3 rice plants maintained plant hormone levels that regulate the expression of several stress-induced genes and reduce adverse effects of salt on plant growth and development and therefore sustains crop productivity.     

Seed characteristics and nutrient composition of selected beans (Phaseolus vulgaris L.) with different ozone tolerance

Ozone sensitivity, nutritional quality, seed characteristics, and growth habit of beans (Phaseolus vulgaris L.) were evaluated in two seperate experiments. In the first experiment the data showed a significant variation among 34 bean accessions for ozone sensitivity following acute exposure of 18-day-old plants to 0.6 µl/l O₃ for 2 hours under environmentally controlled greenhouse conditions. PI-163579, PI-169735, PI-171790, PI-176684, PI-201374, PI-310711, PI-345576, PI-370569, PI-379435, and PI-414831 were identified as tolerant to acute ozone exposures. Protein, oil, starch, sugar, and ash contents in the seed of selected germplasm were determined and no correlation was found between these components and ozone sensitivity. Seed size and growth habit varied considerably among the 34 accessions but were not correlated to ozone sensitivity. In a second experiment, ten accessions, selected from the tolerant ones identified in the first experiment, were subjected to chronic ozone exposure in open-top chambers at 0.04 and 0.08 µl/l concentrations for 7 hours/day 44 days after transplanting. Based on foliar injury and yield reductions, only PI-370569 and PI-414831 were tolerant to prolonged ozone exposure (0.08 µl/l). A significant positive correlation (r=0.83) existed between foliar injury rating from chronic treatments involving 0.04 and 0.08 µl O₃/l and acute exposure (0.6 µl O₃/1/2 hours). The data indicated that acute ozone exposure can be used to initially screen a large number of bean accessions, however, this is an imperfect indicator of ozone sensitivity with chronic exposure.Agricultural Research Station Journal Article Series, No. 191. The use of any trade name varieties and/or vendors does not imply the exclusion of other products or vendors that may also suitable.     

4种沉水植物对再生水中氮磷的去除速率和耐受范围

【目的】研究4种沉水植物对再生水中氮、磷的去除速率和耐受范围,为以再生水作为补水的景观水体沉水植物的选择提供依据。【方法】以野外选取的伊乐藻(Elodea canadensis)、罗氏轮叶黑藻(Hydrilla verticillata)、菹草(Potamogeton crispus)和金鱼藻(Ceratophyllum demersum)4种沉水植物作为供试材料,设置含不同质量浓度TN和TP的再生水,测定有这4种沉水植物的再生水体中TN和TP质量浓度的变化,构建TN和TP质量浓度与培养时间的回归方程,并在回归方程的基础上,研究4种沉水植物对再生水中的氮、磷的去除规律。【结果】在有4种沉水植物的再生水体中,TN和TP质量浓度均随着培养时间的延长呈负指数衰减变化,沉水植物的净化能力不仅与其种类有关,而且与TN和TP初始质量浓度相关。罗氏轮叶黑藻对TN的去除能力最强,金鱼藻最低;伊乐藻对TP的去除能力最强,金鱼藻最小。菹草对氮素的耐受范围较宽,金鱼藻最窄;伊乐藻对磷素的耐受范围最宽,金鱼藻较窄。【结论】当再生水体中TN初始质量浓度为5~15mg/L、TP初始质量浓度为0.5~1.5mg/L时,罗氏轮叶黑藻和伊乐藻对氮磷营养盐的去除速率较高,可作为维持和改善再生水景观水体水质的先锋植物。     

不同基因型玉米萌芽期的抗旱性研究

对4个玉米杂交种辽单24、丹413、沈丹16、沈农87进行了萌芽期的抗旱性研究。结果表明水分胁迫降低了杂交种的发芽势和发芽率,阻碍了胚根和胚芽的生长,也降低了叶片的蒸腾速率和光合速率。但不同杂交种在抗旱性上存在明显差异,在水分胁迫下,抗旱性强的杂交种仍然保持较高的发芽势和发芽率。水分胁迫下,玉米种子的吸水速率减小,但吸水速率与抗旱性间相关性不明显。各品种在20%PEG水分胁迫处理下的萌动吸水伤害率间差异明显,可以作为一个抗旱鉴定指标。研究表明,利用室内高渗溶液萌发法通过对玉米萌芽期抗旱性高度相关的性状的测定得出的萌芽期抗旱性鉴定结果与田间直接鉴定的结果基本相符,说明室内高渗溶液萌发法是鉴定玉米萌芽期抗旱性的一种快速、简便、准确的方法。     

早籼品种苗期耐冷性的遗传研究

 应用人工气候箱低温处理．研究了早籼品种的苗期耐冷性。根据3叶期在6℃下处理48小时，3O℃／25℃ 24小时恢复生长后的叶片黄化程度及48小时恢复生长后的死苗情况，发现3个早籼品种的耐冷性均由一对显性基因控制。品种耐冷性愈差，电导率愈高，以此评价的耐冷性遗传也可能由一对主基因控制。     

碱蓬和滨藜对镉和钠吸收、转运及亚细胞分布特性的比较研究

采用水培试验方法,比较了不同类型盐生植物碱蓬和滨藜的Cd耐性,研究了两者对Cd和Na的富集规律及亚细胞水平上的Cd解毒机制差异。结果表明,Cd胁迫下碱蓬和滨藜的根长、株高及干重等均受到不同程度的抑制,两者的表观毒害症状及对Cd的响应敏感度也存在明显差异;根系耐性指数可以作为评价两者Cd耐性的指标,碱蓬表现出更强的Cd耐性。另外,除1μmol·L-1Cd胁迫下,碱蓬根表的单位面积Cd吸附量均显著高于滨藜;两者吸收的Na大量转运至地上部,吸收的Cd则主要富集在根部,但碱蓬对Cd的转运能力比滨藜弱。亚细胞分布分析发现,两种盐生植物各器官中Cd均主要分布于细胞壁,其次为胞液;细胞壁的固定为两者亚细胞水平上的主要Cd解毒机制,且碱蓬不同器官细胞壁的固定能力比滨藜强,根部Cd亚细胞分布特性对Cd从根部向地上部转运有显著影响。Cd胁迫除产生直接毒害外,也影响碱蓬和滨藜地上部及根部的Na含量,干扰了两者不同器官及亚细胞水平上的正常Na稳态。     

植物耐盐研究概况

盐害是影响农业生产的一个主要环境因素。随着全球环境的恶化，世界很多地区都发生了土地的盐渍化。近年来植物的耐盐研究已经成为研究的热点。本文从植物耐盐的机理、耐盐相关的基因及转基因植物几个方面进行综述，为从事耐盐研究的工作者提供一定的参考。     

几种杂交水稻及其亲本三系幼苗抗冷特性的比较

根据杂交水稻抗冷性选育种的需要,我们研究了低温对五个杂交水稻组合的影响从低温对幼苗根系电解质泄漏,黄化幼苗转绿和幼苗存活率的影响来看:根系外渗液的相对电导率增加,叶绿素合成能力的降低与幼苗存活率具有一致性,其抗冷顺序为粳稻型的秀优57>籼稻型的青优早>汕优63、汕优64和成优64。杂交水稻F_1的抗冷性与母本近似,与父本关系不大,保持系的抗冷性相似于不育系。本文对该结果在杂交水稻抗冷性选育中的意义进行了讨论。     

几个龙生型花生的耐旱形态性状研究

通过人工模拟干旱胁迫处理和比较其它花生类型的耐旱品种，研究几个龙生型花生在缺水条件下的形态特征及恢复生长能力，试验表明，干旱胁迫显著抑制花生地上部营养体生长，但促进主根伸长和根系干物质积累，龙生型花生耐旱性状突出，但不同材料差异较大，马山二洋和托克逊小花生是耐旱性良好的龙生型种质。