干旱胁迫条件下小麦 RILs 群体花后旗叶持绿性遗传特性及其与千粒重的相关性

摘要

To investigate the quantitative genetical characteristics of SPAD of flag leaf after flowering at different sites and its correlation analysis with thousand-grain weight (TGW) ,a 120 recombinant inbred lines (RILs) derived from two Chinese winter wheat cultivars were used .The recipient parent Longjian 19 had strong drought resistance with lower chlorophyll content (SPAD ) ,while the donor Q9086 showed contrasting traits .The results indicated the interaction between water and genotype .There was significantly positive correlation between SPAD of flag leaf and TGW after flower-ing ,while higher correlation ( r=0 .59* * ~0 .69* *) was detected between TGW and SPAD of flag leaf (SPADg ) dur-ing filling stage .The SPADg showed significantly positive effect on TGW ,while that of flag leaf (SPADf ) during flowering stage was opposite .Gross effect of SPAD to TGW in drought stress was significantly higher than those in normal irrigation condition ,and gross effect of SPADg to TGW was higher than SPADf .Heritability of SPAD of flag leaf and TGW were generally lower (hB2=0 .15~0 .44) under different treatments .The number of genes controlling SPADf were 22~36 and 50~59 ,and those controlling SPADg were 24~25 and 31~33 ,while those controlling TGW were 10~11 and 13~14 under drought stress and normal irrigation condition ,respectively .The result indicates the feasibility of using this RILs population in genetical study of wheat drought resistance .%利用抗旱性强的冬小麦品种“陇鉴19”（较低叶绿素含量（SPAD ））与水地高产品种“Q9086”（较高SPAD ）杂交构建的F8重组近交系（RILs ）群体120个株系及其亲本为供试材料，研究雨养和正常灌溉条件下，不同地点花后旗叶SPAD与千粒重（TGW ）相关性及数量遗传特点，评价该群体目标性状遗传变异。结果表明：在不同处理条件下，小麦RILs群体旗叶SPAD和TGW表型变异广泛，多样性指数高，且有超亲分离，存在显著的基因型和水分条件以及基因型×水分条件互作效应。小麦RILs群体花后不同发育时期旗叶SPAD和TGW之间均呈现显著的正相关，其中灌浆期旗叶SPAD （SPADg ）与TGW相关性更高（ r＝0．59**～0．69**）。SPADg对TGW有极显著的正向直接作用，而开花期SPAD （SPADf ）相反。干旱胁迫条件下旗叶SPAD对TGW总效应显著高于正常灌溉，SPADg对TGW总效应显著高于SPADf。不同处理旗叶SPAD和TGW遗传力普遍较低（hB2＝0．15～0．44）；在干旱胁迫和正常灌溉条件下，控制SPADf的基因对数分别为22～36和50～59，控制SPADg 的基因对数分别为24～25和31～33，控制TGW的平均基因对数分别为10～11和13～14。该小麦群体花后旗叶SPAD和TGW表型，及其对水分敏感程度变异丰富，适合进行小麦抗旱性状数量遗传研究。