中国冬小麦微核心种质遗传多样性分析

摘要

为了明确中国冬小麦的遗传多样性,为育种工作提供有益信息,以90份具有广泛代表性的中国冬小麦核心种质为材料,通过连续2年度的水、旱处理,分析了其形态、光合生理及苗期根部共21个性状的遗传变异及广义遗传力；同时利用269对均匀分布于小麦21条染色体的 SSR 标记对供试材料进行遗传多样性分析。结果表明：除穗长、小穗数、净光合速率、胞间 CO2浓度和叶绿素含量5个性状外,其他16个性状均具有比较丰富的遗传变异；以形态性状为主的简单性状(穗叶距、穗下节长、株高、胚芽鞘长、根直径、千粒质量、穗长、叶绿素含量、穗粒数、小穗数、根长、旗叶长)具有较高的遗传力,适宜早代选择；产量性状(单株籽粒产量和单株生物学产量)遗传力中等,但考虑产量是育种改良的核心目标,也可作为早代选择指标；光合生理及复合性状(萌发期根表面积、根体积、胞间 CO2浓度、气孔导度、蒸腾速率和净光合速率)遗传力最低,尤其是光合生理性状易受外界环境的影响且不容易准确测量,不适宜作为早代选择的指标。 SSR 多样性分析表明,中国冬小麦遗传多样性较差；不同基因组间差异显著,其中 B 基因组多样性最丰富,D 基因组多样性最差。%In order to know the genetic diversity of Chinese winter wheat,and to provide useful informa-tion for wheat breeding,90 typical accessions of Chinese winter wheat were selected as research materials, which were planted in normal and drought conditions for two years. The genetic variations and broad sense heritability of 21 wheat traits were analyzed. The results showed that 16 traits had abundant genetic varia-tions(CVg > 10% ) except 5 traits( SL,SN,Pn,Ci and SPAD; CVg < 10% ); the simple traits mainly composed of morphological traits(SDL,UIL,PH,CL,RD,TKW,SL,SPAD,GNPS,SN,RL and FLL) had relatively higher heritability,which were available to be selected in early generations. The yield traits(BY-PP and GYPP) had medium heritability,which were considered to be reliable indexes in early generations as they were the core goal in wheat breeding. Photosynthetic and other complex traits(Pn,E,Gs,Ci,RS and RV) were of low heritability,especially the photosynthetic traits which were easily influenced by the environment and could not be evaluated accurately,thus they were unsuitable to be selected in early gen-erations. All the 90 wheat accessions were analyzed with 269 SSR markers distributing throughout the wheat genome. The result showed that the genetic diversity of the Chinese winter wheat accessions was at a lower level. Significant difference of genetic diversity was observed among the three genomes,of which the B genome showed the highest diversity and the D the lowest.