大豆品种苗期根系性状的遗传变异及其与耐逆境胁迫的关系

从301份黄淮海和长江中下游地区代表性大豆地方品种和育成品种(系)中按根系类型选取62份,用以研究不同生态区大豆苗期根系性状的遗传特点、与地上部性状的相关以及与逆境胁迫的关系.大豆苗期一级侧根数、主根长、根干重、总根长和根体积等性状,在品种间、各苗龄间均存在显著遗传变异.不同生态区间生长进度不同,长江中下游晚熟品种的根干重、总根长、根体积发育速度较快,而北方早熟品种的根系发育较慢.根系性状与整株干重呈高度相关;根干重、根总长和根体积的相对值与耐旱平均隶属函数值,一级侧根数、主根长、总根长、根体积、根干重的相对值与耐铝毒平均隶属函数值呈极显著相关,且根系性状的相对值在品种间存在显著变异,可用做耐逆性选择的根系指标.黄淮海区品种的耐旱相关根系性状值高于长江中下游区品种,表明耐旱种质的相关根系性状具有生态适应性.

GENETIC VARIATION OF ROOT TRAITS AT SEEDLING STAGE AND THEIR RELATIONSHIP WITH STRESS TOLERANCE IN SOYBEAN

Sixty two accessions of soybean(Glycine max(L.) Merr.) selected from 301 representative entries from Huanghuaihai and Middle-Lower Changjiang Valleys according to their root performance were used to study their genetic variation of root traits at seedling stage and their relationship with above-ground traits and tolerance to abiotic stresses.Dry root weight,total root length and root volume of accessions from Middle-Lower Changjiang Valleys with later maturity developed more quickly than those from Huanghuaihai Valleys with earlier maturity.The correlations between these root traits and whole plant dry weight were pretty high,those between the mean membership index of drought tolerance and the relative values of total root length,root volume and dry root weight per plant were all significant at 0.01 level and so did for the correlations between mean membership index of aluminum toxin tolerance and the stressed to unstressed relative values of number of lateral roots,tap root length,total root length,root volume and dry root weight.These relative root traits had wide variation among accessions and could be used for identification of drought and aluminum tolerance.