Abstract: An experimental system created by grafting technology was used in this study to evaluate the contributions of different genotypic roots to grain yield, and clarify its relation to root traits, so as to provide a theoretical basis for root improvement in soybean. A total of 22 cultivars were used as rootstocks to graft with the same scion of Liaodou 21, respectively. The root traits and grain yield were measured under different soil water treatments, and then the self-grafted Liaodou 21 was used as check to calculate the ratio of yield change of each graft, which was defined as root contribution values. Results showed that significant difference in grain yield was found among grafts. The root contribution value of 22 soybean cultivars varied from -33.61% to 26.77% under well-watered condition, while varied from -29.26% to 62.80% under water stress condition. Under well-watered condition, the root contribution value had no significant relationships with root length, root surface area, root volume and root tissue density, but negatively correlated with root dry mass and root-shoot ratio. Under water stress, the root contribution value was negatively correlated with root length, root surface area, root volume, root dry weight, root-shoot ratio and root tissue density. The results suggested that the soybean germplasms which had developed rooting with a low investment on dry matter should have important utilization value for soybean breeding with high yield and drought resistance.

Key words: Glycine max, Grafting, Root, Grain yield, Water stress

CLC Number: 

• S324

• S565.01