Genetic analysis of root characters in soybean using a recombinant inbred line population at two phosphorus levels | 不同磷水平下大豆根系性状的遗传特性分析

Chino. 在田间两种磷水平下，应用大豆RIL群体对根总长、根总表面积、根宽、根冠比、根干重和根磷含量等6个根系性状参数和6个涉及植株磷含量、生物量及产量性状的指标进行遗传特性研究，结果发现在不同磷水平下，大豆重组白交系群体根系性状的变异幅度较大，符合正态分布的特征。土壤磷水平不仅促进了大豆根系形态的变化，同时也影响到根系构型的改变。低磷胁迫条件下，根系性状与植株磷含量、生物量及产量之间呈极显著相关关系，并且这些根系性状都具有较高的广义遗传率（0．47～0．60），可以作为选择指数应用于作物磷营养效率的遗传改良中。在根系性状的6个指标中，以根总长、根总表面积、根干重、根磷含量等4个参数与植株吸磷量、生物量及产量的关系最为密切，可以作为评价不同磷水平下植物基因型差异的可靠指标，而根宽和根冠比则可作为特定的磷胁迫条件下基因型差异的筛选指标。[著者文摘]

Inglés. Plant root system is very important for phosphorus （P） uptake from the soil. In this study, two contrasting genotypes of soybean （Glycine max L.）, BD2 and BX10, and their 106 Fg-derived recombinant inbred lines （RILs） were grown in the field with low P and high P treatments. The important root traits, including total root length （RL）, root surface area （SA）, root extent （RE）, root to shoot ratio （RRS）, root dry weight （DRW）, root P content （RPC） and others agronomic parameters such as P content, biomass and yield were investigated. The results indicated that the parents and the RIL population differed significantly in the six root traits which were complied with normal distribution. Phosphorus availability not only greatly affected root morphology, but also its architecture. Under low P conditions, root traits with high broad-sense heritability （0.47～0.60） significantly correlated to P content, biomass and yield, which could be used as a selecting index for genetic improvement on P efficiency in crops. Among the six root indices, RL, SA, DRW and RPC are closely associated with P content, biomass and yield at both two P levels, which could be used as reliable criteria to evaluate genetic variations in soybean under different P availabilities, and RE and RRS could be used as selecting indices to evaluate genetic variations under P deficiency conditions in soybean.