Abstract:

Chlorophyll content of plant leaf is an important trait associated with photosynthesis, as a major photosynthetic pigment and index of crop field management and crop breeding. In the current study, a set of RIL population derived from Bogao and Nannong 94-156 was used to detect quantitative trait loci (QTLs) associated with chlorophyll content (CC) at four growing stages, and their correlations with three yield-related traits including seed yield, apparent biological yield and apparent harvest index were analysed. The primary results indicated that QTLs associated with the accumulation of chlorophyll content were detected and mapped on LG-D1a+Q, F, G, H, L, and M, each QTL explained 6.9%–23.4% of phenotypic variation. There were no QTLs detected to be expressed across two years at the V6 and R2 growing stages. However, at the R4 stage four QTLs (qccF.1, qccG.1, qccH.1 and qccM.1) expressed in both years, and one of them (qccH.1) also expressed at R6 stage in two years. QTLs qccB2-1.1 and qccL.1 associated with the net increment of chlorophyll content were detected and mapped on LG-B2 and L, expressed from R2 to R4 and from R4 to R6, and explained 6.4%–9.8% and 29.5%–31.3% of phenotypic variation, respectively. qccB2-1.1 showed positive additive effect from R2 to R4 and negative additive effect from R4 to R6, while qccL.1 showed negative additive effect from R2 to R4 and positive additive effect from R4 to R6. These two QTLs co-located with QTLs for seed yield, confirming that there is significant correlation between seed yield and chlorophyll content at late growing stages.

Key words: Soybean [Glycine max (L.) Merr.], Chlorophyll content, Yield, Quantitative trait loci (QTLs)