灌溉水平及灌溉间隔对大豆植株干物质积累的影响

采用桶栽方法,选用黑农48为试验材料,设计4个灌溉水平及4种干旱胁迫历时进行交叉试验,研究了灌溉水平及干旱胁迫历时对大豆干物质积累的影响。结果表明,花荚期大豆植株叶、茎、根和荚果更易受干旱胁迫历时影响,干旱胁迫历时越短越有利于植株生长,灌溉水平对植株的生长影响相对弱于干旱胁迫历时。植株各器官干质量的等高线图表明高灌溉水平、短干旱胁迫历时比低灌溉水平、长干旱胁迫历时有绝对优势,同时也表现出高灌溉水平、长干旱胁迫历时处理与低灌溉水平、短干旱胁迫历时处理之间具有相似性。     

旱涝交替胁迫下水稻茎节发育及其抗倒伏能力

采用盆栽试验,设置4个旱涝交替胁迫处理[旱-涝-旱连续胁迫,涝后水分自然落干,待达到水分控制下限后开始旱胁迫;分蘖期:涝为保持水深10 cm,包括轻旱(T-LD)和重旱(T-HD)2个处理;拔节期:涝为保持水深15cm,包括轻旱(S-LD)和重旱(S-HD)2个处理],并以常规灌溉(CK)为对照,研究了不同生育期(分蘖期和拔节期)旱涝交替胁迫条件下水稻茎节发育状况和茎秆抗倒伏能力,并分析了茎节、株高、倒伏指数、抗折力之间的相关关系。结果表明,旱涝交替胁迫后,拔节后期和黄熟期水稻第一、二、三茎节生长发育均受到抑制。拔节后期各处理株高显著低于CK,且第一茎节S_内较CK降低了20.84%~39.07%;而黄熟期T-LD、T-HD处理株高却超过CK,且TLD和T-HD处理第一茎节S_外、S_内均较CK显著降低,而S-HD处理第一茎节S_内较CK显著降低了69.70%,S_截较CK显著增加了34.78%。拔节后期和黄熟期水稻各茎节长度相互之间呈显著正相关(p0.01),且第二茎节长度与第三茎节相关系数最高,但各茎节长度与株高相关性较弱;另外,株高的增加不利于水稻抗倒伏。黄熟期水稻第一茎节S_外与倒伏指数显著正相关,而与抗折力负相关,第四茎节S_截与倒伏指数显著负相关,与抗折力显著正相关。第一、二茎节S_外和S_截的增加不利于水稻抗倒伏,第三、四茎节截面积的增加有利于水稻抗倒伏。     

Estimates of heritability for,and relationships between,root and shoot characters of white clover. I. Replicated clonal material

Summary A total of 749 genotypes from a number of white clover (trifolium repens L.) cultivars and populations, many collected from dryland areas, were cloned and grown in field titles. Several morphological characters, including leaf size, number and diameter of large nodal roots (taproots), and proportion of root weight that was classified as taproot were measured. There was large variation between lines and genotypes for all characters measured, and differences between genotypes within lines are also reported. Broad sense heritability estimates were higher (>0.5) for leaflet width, petiole length and stolon diameter, than for all root character heritability estimates which were between 0.2 and 0.4.     

Use of Canopy Temperature Measurements as a Screening Tool for Drought Tolerance in Spring Wheat

Remotely sensed infrared canopy temperatures provide an efficient method for rapid, non-destructive monitoring of whole-plant response to water stress. Field studies were conducted in 1992 and 1993 to evaluate the potential for using canopy temperatures to screen for drought tolerance in wheat. In both years, 12 spring wheat (Triticum aestivum L.) genotypes were grown under two irrigation levels (well-watered and moisture-stressed) imposed between tillering and anthesis with a line-source sprinkler irrigation system. Canopy temperature measurements were taken in well-watered and moisture-stressed plots between 1330 and 1430 h (MDT) on five clear days in 1992 and seven clear days in 1993 during the late vegetative and early reproductive growth periods following closure of the plant canopy. Genotypes exhibited differences in mean canopy temperatures across the two irrigation levels and two years. Klasic consistently had the highest canopy temperature under moisture-stressed conditions, while Bannock and Pondera had the lowest. Bannock, Yecora Rojo and Klasic had the warmest canopies under well-watered conditions, while Vandal, Amidon and Rick had the coolest. Plot-to-plot variation in canopy temperature under water stress conditions was evident for differences in grain yield. Significant correlations between canopy temperature and yield under moisture-stress conditions and drought susceptibility index values indicated the potential for screening wheat genotypes for drought response.     

茶树新梢生育的内源激素水平及其调控机理（第三版）：干旱胁迫对茶树内源激素的影响

以耐旱性不同的福鼎白毫和紫笋茶树品种为对象，研究了不同干旱胁迫强度对茶树叶片含水量与内源激素水平的影响。结果表明：随干旱胁迫持续，叶片失水递增，叶片含水量福鼎白毫＞紫笋；胁迫过程中茶树叶片IAA和ABA含量不断增加，Zeatin含量不断下降，ABA含量变化与叶片含水量呈线性负相关，与叶片IAA含量呈线性正相关，IAA／ABA比值随干旱胁迫的持续而下降，耐旱性较强的福鼎白毫下降幅度较紫笋大，ABA／ZT比值在胁迫过程中不断上升，其比值福鼎白毫＞紫笋，这与茶树品种的耐旱强弱相一致，ABA／ZT比值的变化与叶片含水量呈线性负相关。     

水稻抗旱节水栽培技术

针对水田面临严重缺水局面,为了缓解水田旱情,从选用耐旱品种、培育壮秧、免耕轻耙、间断灌水等栽培技术入手,介绍了水稻抗旱节水栽培技术的关键环节。提出了耐旱高产品种、培育壮秧、旱整地、重施底肥、全层施氮、根据水稻不同生育期间断灌溉等具体节水措施。     

茶树谷胱甘肽过氧化物酶编码基因CsGPX1功能分析

为明确茶树[Camellia sinensis(L.)O.Kuntze.]谷胱甘肽过氧化物酶(Glutathione peroxidases,GPX)编码基因CsGPX1的功能,本文利用茶树转录组数据克隆获得CsGPX1的编码区全长序列,进行序列比对与分析,在此基础上,将CsGPX1在烟草中进行过表达获得转CsGPX1基因烟草,并比较野生型烟草与转基因烟草耐旱性的差异,验证CsGPX1功能。序列分析表明,CsGPX1编码序列(CDS)长723 bp,编码240个氨基酸。BLAST比对发现,该基因与桃树(Prunus persica)的GPX基因具有高度同源性(>85%)。CsGPX1编码的氨基酸序列具有GPX蛋白保守特征序列和区别于其他家族成员的特有的结构域——磷脂氢谷胱甘肽过氧化物酶(PHGPX)。干旱胁迫处理结果显示,过表达CsGPX1烟草株系抗旱性强于野生型。GPX酶活性测定结果表明,转基因植株的GPX酶活性高于野生型植株。以上研究结果表明,过表达CsGPX1可提高转基因烟草的耐旱能力,说明CsGPX1可能与茶树的耐旱性能相关。本研究为提高茶树的耐旱性能研究提供了新的理论途径,并对降低茶园管理的成本具有一定的积极意义。     

应用隶属函数法鉴定水稻的抗旱性

采用隶属函数法对25个水稻材料进行了抗旱性综合评价,结果表明:在干旱处理的情况下,短生育期材料生育期缩短,长生育期材料则延长;有效穗、千粒重、株高、每穗实粒数及单株粒重则普遍下降,但抗旱性强的材料降幅较小.依据隶属函数值,筛选出了8份强抗旱材料,可作为水稻抗旱育种的抗旱资源.     

草坪草对干旱胁迫的反应概述

干旱胁迫是影响草坪草生长最主要的环境胁迫因子之一。在干旱胁迫下,草坪草的根、茎、叶均会表现出一定的生态适应性,还会发生叶片蒸腾和光合作用减弱、渗透调节物质累积、活性氧代谢失调等生理生化反应,而且在细胞水平和基因水平上也会发生变化,这都与草坪草的抗旱调节机制有着密切的联系。目前我国关于草坪草的抗旱性研究还处于起步阶段,基因工程技术的研究和应用是今后的主要发展方向。     

Mapping of QTLs for Germination Characteristics under Non-stress and Drought Stress in Rice

Identification of genetic factors controlling traits associated with seed germination under drought stress conditions, leads to identification and development of drought tolerant varieties. Present study by using a population of F2：, derived from a cross between a drought tolerant variety, Gharib （indica） and a drought sensitive variety, Sepidroud （indica）, is to identify and compare QTLs associated with germination traits under drought stress and non-stress conditions. Through QTL analysis, using composite interval mapping, regarding traits such as germination rate （GR）, germination percentage （GP）, radicle length （RL）, plumule length （PL）, coleorhiza length （COL） and coleoptile length （CL）, totally 13 QTLs were detected under pole drought stress （-8 MPa poly ethylene glycol 6000） and 9 QTLs under non-stress conditions. Of the QTLs identified under non-stress conditions, QTLs associated with COL （qCOL-5） and GR （qGR-1） explained 21.28% and 19.73% of the total phenotypic variations, respectively Under drought stress conditions, QTLs associated with COL （qCOL-3） and PL （qPL-5） explained 18.34% and 18.22% of the total phenotypic variations, respectively. A few drought-tolerance-related QTLs identified in previous studies are near the QTLs detected in this study, and several QTLs in this study are novel alleles. The major QTLs like qGR-1, qGP-4, qRL-12 and qCL-4 identified in both conditions for traits GR, GP, RL and CL, respectively, should be considered as the important and stable trait-controlling QTLs in rice seed germination. Those major or minor QTLs could be used to significantly improve drought tolerance by marker-assisted selection in rice.