籼粳稻杂交衍生RIL系的苗期抗旱性评价

Evaluation of Seedling Drought Resistance of RIL Derived from Indica Rice and Japonica Rice

为鉴定籼粳稻杂交衍生系的苗期抗旱性,以课题组自育的高代抗逆品系ZD15为母本、籼稻品种IR29为父本,以及杂交衍生的重组自交系群体120份为试验材料,利用PEG-6000对各材料苗期进行干旱胁迫处理,测定根长、根冠比、地上部鲜重、地下部鲜重、地上部干重和地下部干重;利用PEG-6000对各材料芽期进行干旱胁迫处理,测定芽鞘长和芽长。采用主成分分析和隶属函数法对各材料的抗旱性进行综合评价,根据综合抗旱D值可将122份材料分成3类,D值在0.201～0.400之间的有33份,属于不抗旱材料;D值在0.401～0.600之间的有79份,属于中等抗旱材料;D值在0.601～0.800之间的有10份,属于抗旱材料。利用D值进行逐步回归分析,结果表明根长、根冠比、地上部鲜重、地下部鲜重、地上部干重、地下部干重、芽鞘长和芽长8个性状均可作为水稻苗期抗旱性的评价指标。本研究筛选出的抗旱材料,可作为育种中间材料进一步培育,或作为育种资源加以利用,以丰富本区水稻育种的资源库。

This study attempted to identify the seedling drought resistance of RIL population from an indica and japonica crossing lines.A population of 120 recombinant inbred lines(RIL),which were derived from a cross between an elite indica cultivar IR29 and a drought-resistant japonica line ZD15,were used.An artificial drought stress was mimicked by PEG-6000 treatment.These parameters including the germ length and coleoptile length at germination stage,as well as the root length,root-shoot ratio,shoot fresh weight,root fresh weight,shoot dry weight and root dry weight at seedling stage,were measured.With the principal component analysis and membership function method,an objective comprehensive evaluation value(D value)of drought resistance was obtained.According to the D value,the122 rice lines(or variety)were divided into three groups.The group Ⅰ containing 33 lines with D value between 0.201 and 0.400,was a drought sensitive group.The group Ⅱ containing 79 lines with D value between 0.401 and 0.600,was a moderate drought resistant group.The last group containing 10 lines with D value between 0.601 and 0.800,was a drought resistant group.Using stepwise regression and principal component analysis,these eight traits were selected to be evaluation indicators for drought resistance at seedling stage of rice.Taken together,the drought resistant lines selected in this study can be further cultivated as breeding intermediate materials,or used as breeding resources to enrich the rice breeding resource in Ningxia.