大豆种质资源不同生育时期抗旱性鉴定评价

Evaluation on Drought Resistance of Soybean Germplasm Resources at Multiple Growth Periods

大豆是重要的植物油脂和蛋白来源,干旱是限制大豆生长发育及产量的重要因素之一。为研究大豆不同生育时期对干旱胁迫的反应,综合评价大豆种质资源抗旱性,筛选抗旱优异种质,本研究在大豆芽期、苗期和全生育期分别采用改进后的抗旱性鉴定方法对253份种质资源进行鉴定,测定根长、株高、百粒重等形态指标,计算发芽率、反复干旱存活率、加权抗旱系数等评价指标,通过相关分析和回归分析筛选抗旱性评价指标,进行大豆种质资源抗旱性综合评价。结果表明,干旱胁迫后,测量指标值降低幅度较大(10.27%~96.62%),与正常灌水处理呈极显著差异(P<1.6×10^(-9))。相关性和回归分析表明,大豆芽期、苗期和全生育期的抗旱评价值间无显著相关性;晚熟材料抗旱性强于早熟材料。筛选出芽期(发芽率)、苗期(反复干旱存活率)和全生育期(单株荚数、单株粒数、单株粒重和单株生物量)抗旱性鉴定评价指标。基于本研究筛选出的评价指标和方法,鉴定出芽期、苗期和全生育期同时表现极强或强抗旱性种质7份,在2个时期同时表现极强或强抗旱性种质50份。本研究为大豆种质资源抗旱鉴定评价及抗旱育种亲本的选择提供理论指导和材料基础。

Soybean is a globally-important crop plant that supplies edible oil and plant protein.Drought is one of the most important abiotic stresses decreasing the growth and yield in soybean.In order to study the response under drought stress conditions,evaluation of drought resistance at multiple growth stages(germination,seedlings,whole growth period)was conducted in 253 soybean germplasm resources.Morphological indicators such as root length,plant height,100-seed weight were measured,and stressful indicators such as germination rate,repeated drought survival rate,and enhanced drought resistance coefficient were calculated.The drought resistance evaluation index,which reflected the drought resistance of soybean germplasm resources,had been identified through correlation analysis and regression analysis.The drought stress treatment resulted in dramatic decrease on the measured index value(10.27%-96.62%),and significant difference if compared with that of the normal irrigation treatment(P<1.6×10^(-9))was observed.No significant correlation between the values of drought resistance at multiple growth periods was detected.These germplasm accessions showing late maturity showed better performance on drought resistance to that of late maturing accessions.The drought resistance indexes qualified for the germination period(germination rate),the seedling period(survival rate of repeated drought)and the whole growth period(the number of pods per plant,the number of seeds per plant,the grain weight per plant and the biomass per plant)have been identified.Seven elite accessions,which showed extremely strong or strong drought resistant under three treatment conditions were obtained,and fifty accessions at two treatment conditions were obtained.Collectively,this study provided theoretical guidance and germplasm resource for deciphering drought resistance basis and identifying the elite parental lines used for soybean breeding.