Abstract:

【Objective】 To explore the additive (A), epistatic (AA) and quantitative trait locus (QTL) ×environment interaction effects (QE) of QTL on dry matter accumulation of soybean seed for deepen understanding the nature of the yield formation and accelerating the breeding process. 【Method】 The aim of the present study was to measure A, AA and QE effects of QTL on dry matter accumulation in a population of 143 F5:9,F5:10 and F5:11 derived recombinant inbred lines developed from the cross between the soybean cultivars Charleston and Dongnong 594. 【Result】 Thirteen QTLs with A effect were detected at different developmental stages, eight of which had significant additive × environment (AE) effect. Fourteen AA pairwise QTLs were found, eight of which showed significant epistatise × environment (AAE) effect. Furthermore, only dmaC2_2, QTL with A effect could be found from 30 day to 80 day developmental stage, other QTLs with A effect and 14 AA pairwise QTLs were only found at some developmental stages. 【Conclusion】 The number of QTL with A effect and phenotypic variation explained by QTL with A effect, present “S” curve from 30 day to 80 day developmental stage, which was similar to phenotypic variation of dry matter accumulation of soybean seed. However, phenotypic variation explained by these AA pairwise QTLs was relatively stable and small. Additive effect, being high in 30 day developmental stage, decreased from 40 day to 70 day developmental stage, rising at 80 day developmental stage. Epistatic effects continuously rised from 30 day to 70 day developmental stage, slightly declined at 80 day developmental stage. QTL×environment effect had a greater impact on the dry matter accumulation of soybean seed from 30 day to 80 day developmental stage. QTL with additive effect, mostly located in linkage group C2 (the interval from OPK14_70 to satt134, corresponding to QTL including dmaC2_1, dmaC2_2 and dmaC2_3 ) at six developmental stages, especially at 30 day developmental stage. Loci of linkage group of QTL with additive effect had most change from 40 day to maturity, which had selectivity at developmental stage. QTL with epistasis effect, mostly located between linkage group C2 (the interval from OPK14_70 to satt134, corresponding to QTL dmaC2_1) and linkage group D1b (the interval from satt537 to sat_135, corresponding to QTL dmaD1b_1) at most developmental stages, except for 50 day developmental stage.

Key words: soybean (Glycine max L. Merri), dry matter accumulation of seed, QTL, additive effect, epistemic effect, environment interaction effects