水稻抗旱性的研究进展

随着全球水资源的日益匮乏和旱灾的日趋严重,水资源短缺正成为制约我国农业发展的重要因素。培育抗旱栽培稻品种并实现水稻旱种,不但可较大程度地节约水资源,且有利于稳产增产、节约能源和减少环境污染,故栽培稻的抗旱性研究作为稻作科学研究的重要课题显得愈来愈重要。本文从水稻抗旱性鉴定形态指标、生理指标和分子标记研究三方面分别概述,并对今后水稻抗旱性方向进行了探讨。     

辽粳系列不同水稻品种的抗旱性比较研究

选用8个辽粳系列水稻品种,进行抗旱性生理研究,结果表明:辽粳326、辽粳454、辽粳9号为辽宁省不同时期的主栽品种,其抗旱性均好于对照品种辽粳5,而辽粳6、辽粳10和辽梗180的抗旱性不及辽梗5.     

三唑酮提高花生幼苗抗旱性的效应

在停止供水条件下,三唑系杀菌剂三唑酮(300ppm)喷施花生幼苗后,引起叶片气孔关闭,降低植物蒸腾失水量,提高了叶片相对含水量,改善了植物水分状况,提高了花生幼苗的抗旱性。三唑酮使植物矮化,光合能力增强,在大田应用很有潜力。     

不同干旱胁迫条件下水稻品种的抗旱性比较研究

采用2种不同的干旱胁迫处理,研究了不同水稻品种在水、旱作时的产量表现,并依据成熟期产量和产量构成因素的表现,评价和剖析其抗旱性。结果表明：（1）不同水稻品种在旱作时的生长特性、产量等与水作时相比,会发生改变：旱作条件下,产量所受影响较小的有冈优725和冈优527,说明这两品种对旱作具有更强的适应性。（2）抗旱性分析发现,产量构成因素的抗旱性存在着较大差异,有些材料表现生育中、后期均抗旱,有些材料只在某一个生育时期表现较强的抗旱性。     

水稻苗期抗旱性的QTL分析

利用251个株系组成的Maybelle/白叶秋的加倍单倍体群体,构建了由226个SSR分子标记组成的遗传图谱。通过两年抗旱棚苗期抗旱性鉴定,应用复合区间作图法和QTLNetwork2.0对水稻苗期抗旱性进行QTL定位及互作效应分析。利用前者在两年共检测到5个抗旱性相关QTL,分别位于第2、3、5、6和8染色体;而通过后者在第2、3、5和6染色体上也找到了抗旱性相关的QTL,并且通过两种方法检测到的第3、5、6染色体上的3个QTL所在区间吻合;还发现4个具有上位性的QTL。所有抗旱性QTL的加性效应均为正值,表明来自父本白叶秋的这些抗旱性位点可以提高水稻的抗旱性。     

应用隶属函数法综合评价水稻主栽品种抗旱性的研究

选用部分形态、产量和生理指标,应用隶属函数法对26个主栽水稻品种进行了抗旱性综合评价,结果表明:在干旱胁迫条件下,各品种的单株产量、单株有效穗、结实率、穗长及叶片相对含水量、叶绿素含量显著下降;根据这些指标的平均隶属函数值,鉴定出了Y两优1号等7个抗旱性较强的品种和两优培九等3个对干旱敏感的品种。     

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.     

6—BA提高玉米幼苗抗旱性机理初探

叶面喷施１０＾－５ｍｏｌ／Ｌ的６－ＢＡ可以提高水分胁迫条件下玉米幼苗的光合速率、叶绿素含量、光合羧化酶及细胞保护酶活性，降低气孔阻力和ＭＤＡ含量，减轻水分胁迫下活性氧对膜的伤害，增强玉米幼苗的抗旱性。     

杂交水稻与常规水稻秧苗根系比较研究

从生理特性、形态特征、地上部与地下部关系等方面对杂交水稻与常规水稻秧苗根系进行了比较研究。结果表明：秧苗发根力、根系活力、根系分布、各级根长、根粗、根数以及根毛均以杂交水稻优于常规水稻。秧苗叶鞘、叶片维管束数也以杂交水稻占优势。     

水稻幼苗根叶伸长动态观察

为培育合格的机插秧苗,观察了水稻幼苗根叶伸长动态。结果表明,N节叶片、N-1节叶鞘、N-3节节根同步伸长;1叶1心期,第一层节根—胚芽鞘节节根萌发伸长,至4叶1心期,共有4节节根及其分枝根萌发,在秧盘底部缠结成网,确保秧苗连片不散,便于带土机插。     

杂交稻抗旱性状的筛选研究

以淹水、旱地试验为处理，通过对9个杂交稻组合主要形态、农艺性状对单株产量的相关、逐步回归、通径和灰色关联分析，筛选出穗茎粗（穗颈节处直径大小）、结实率、谷粒宽和倒1节间长等性状作为南方稻区杂交稻组抗旱性的鉴定指标。根据试验结果，认为在杂交稻抗旱育种上应以选择穗茎粗、多穗多粒、结实率高、谷粒宽、倒1节间长、生育后期进程快、早郭的组合为好。     

海南山栏稻农艺特征与抗旱生理特性研究

研究了１２个山栏稻原始种质的主要农艺性状、品质特征及抗旱生理特性，并与水稻不同类型的对照进行比较分析。结果表明，在旱地栽培条件下，山栏稻的穗长、穗粒数、衙粒重及单株产量均显高于对照水稻．但不时也表现高杆、穗颈过长、移片大且披垂等不良性状。在品质方面，山栏稻糙米粗蛋白含量、１７种氨基酸含量及２种必需氨基酸含量显高于水稻对照。山栏稻种子在高渗溶液中的发芽率、离体叶片保水率、质膜稳定性和分蘖秆长整齐     

聚乙二醇模拟干旱对耐低钾水稻幼苗光合特性的影响

以早籼品种瑰宝8号及其变异后代耐低钾水稻为材料,用20%PEG6000模拟干旱,对幼苗光合特性进行了研究,并对测定指标进行相关性分析。模拟干旱胁迫下,耐低钾水稻幼苗具有相对较高的钾含量、钾素利用效率、生物量、水势、光合速率、气孔导度和胞间CO2浓度。相关分析表明,水稻幼苗钾含量和钾素利用效率与生物量、光合速率、气孔导度、胞间CO2浓度和水势呈显著正相关。     

水稻钵育摆栽技术示范总结

黑龙江省建三江分局创业农场一队试验示范了水稻钵育摆栽技术,总结出该项技术具有秧苗素质好、移栽保全苗、生育进度快、质优产量高等优点。同时指出,水稻实行钵育摆栽选用日本产钵盘,重点抓好营养土质量、严格选种、机器播种,稻田实行三化管理,提早移栽,本田要加强水肥等方面的管理。     

Improvement of Upland Rice Variety by Pyramiding Drought Tolerance QTL with Two Major Blast Resistance Genes for Sustainable Rice Production

Varalu is an early maturing rice variety widely grown in the rainfed ecosystem preferred for its grain type and cooking quality. However, the yield of Varalu is substantially low since it is being affected by reproductive drought stress along with the blast disease. The genetic improvement of Varalu was done by introgressing a major yield QTL, qDTY_12.1, along with two major blast resistance genes i.e. Pi54 and Pi1 through marker-assisted backcross breeding. Both traits were transferred till BC₂ generation and intercrossing was followed to pyramid the two traits. Stringent foreground selection was carried out using linked markers as well as peak markers (RM28099, RM28130, RM511 and RM28163) for the targeted QTL (qDTY_12.1), RM206 for Pi54 and RM224 for Pi1. Extensive background selection was done using genome-wide SSR markers. Six best lines (MSM-36, MSM-49, MSM-53, MSM-57, MSM-60 and MSM-63) having qDTY_12.1 and two blast resistance genes in homozygous condition with recurrent parent genome of 95.0%-96.5% having minimal linkage drag of about 0.1 to 0.7 Mb were identified. These lines showed yield advantage under drought stress as well as irrigated conditions. MSM-36 showed better performance in the national coordinated trials conducted across India, which indicated that improved lines of Varalu expected to replace Varalu and may have an important role in sustaining rice production. The present study demonstrated the successful marker-assisted pyramiding strategy for introgression of genes/QTLs conferring biotic stress resistance and yield under abiotic stress in rice.     

杂草稻幼苗期耐旱性的初步筛选与评价

采用盆栽试验,在人工设置干旱胁迫条件下,对不同地区杂草稻幼苗期的耐旱性进行了鉴定。杂草稻具有良好的抗逆能力,本文利用33份杂草稻种质资源,在苗期对其进行抗旱性筛选,调查了幼苗存活率,抗衰度等指标,计算了苗期抗旱性综合系数。结果表明,大部分杂草稻在苗期具有较强抗旱性,为下一步更深入的研究奠定基础。     

Association and Heritability Studies for Drought Resistance under Varied Moisture Stress Regimes in Backcross Inbred Population of RiceAssociation and Heritability Studies for Drought Resistance under Varied Moisture Stress Regimes in Backcross Inbred Population of Rice

Drought stress is one of the major constraints affecting rice production and yield stability in the rainfed regions. To understand the physiological basis of drought resistance related component traits, we used a backcross inbred population of rice under three kinds of moisture regimes viz., non-stress, moderate （24.48%） and severe stress （73.97%） conditions which reflect the differential responses of the genotypes to varying stress intensities. The plot yield, 1000-grain weight, panicle exsertion and canopy air temperature difference exhibited high heritability under the control conditions, whereas spikelet sterility and single plant yield exhibited high heritability under the moderate stress conditions. Traits such as days to 50% flowering, plant height and osmotic potential showed high heritability under the severe stress conditions. Plot yield under stress was significantly and positively correlated with harvest index and 1000-grain weight, but negatively associated with leaf rolling score and days to 50% flowering. The drought susceptibility index and drought response index were negatively correlated between each other both under the moderate and severe stress conditions. The derived traits viz., difference in panicle length between the control and the severe stress was associated with osmotic adjustment measured under field conditions. Difference in plant height and panicle length was negatively associated with plot yield under stress.     

水稻生理特性与抗旱性的相关分析及QTL定位

利用籼稻品种IR64和粳稻品种Azucena杂交产生的包含110个加倍单倍体株系的群体,在干旱胁迫和正常水分条件下,连续在2004年和2005年于抽穗期分别测定了叶片水势、相对含水量、叶绿素含量(SPAD值)、游离脯氨酸含量、气孔导度和蒸腾速率,并于成熟期取样,计算抗旱系数。与正常水分状况下相比,干旱胁迫条件下叶片的游离脯氨酸含量的增加达极显著水平,干旱胁迫条件下叶片的相对含水量、水势、叶绿素含量和气孔导度的降低均达显著或极显著水平。相关分析表明,在干旱胁迫条件下,叶片相对含水量、叶片水势与抗旱系数呈显著或极显著正相关。 利用175个RFLP标记构建的遗传连锁图谱分析了与抗旱性相关的叶片生理指标,共检测到与抗旱性相关的6个生理指标的7个加性QTL,31对上位性QTL,其中有2个主效QTL、9对上位性QTL存在环境互作效应。在两种水分条件下检测到的QTL结果有较大差异,说明干旱胁迫对控制与抗旱性相关的叶片生理性状基因的表达有显著的影响。在6个抗旱相关生理指标中,检测到的控制叶片气孔导度和水势的QTL较多,有3个加性QTL和8对上位性QTL控制气孔导度,有8对上位性QTL控制水势。