Genetic Analysis of Biomass and Photosynthesis Related Parameters in Wheat (Triticum aestivum L.) Grown in Different Light Intensities

Growth light intensity plays pivotal roles in photosynthesis, biomass accumulation, and yield formation of cereal crops. In the present study, by using a doubled haploid population a quantitative trait locus (QTL) analysis was carried out to explore the genetic response of biomass and photosynthetic parameters in wheat to growth light intensity. The results showed that wheat seedlings grown in high light (HL) accumulated more biomass with lower content of chlorophyll (Chl) and carotenoids (Car) and maximal photochemical efficiency of photosystem II (Fv/Fm) in fully developed leaves. In contrast, when grown in low light (LL), wheat seedlings produced less biomass with higher content of Chl and Fv/Fm. The QTL analysis revealed a total of 48 QTLs associated with the genetic regulation of biomass and photosynthetic parameters in response to growth light intensity. Of these, 14 QTLs, 15 QTLs, 9 QTLs, and 10 QTLs were associated with biomass, Chl, Car, and Fv/Fm and 19 QTLs, 13 QTLs, and 16 QTLs were detected in LL, ML (medium light), and HL, respectively. These QTLs were mapped to 15 chromosomes: 1A, 1B, 1D, 2B, 2D, 3A, 3B, 4B, 5A, 5B, 5D, 6A, 6B, 7A, and 7B which individually explained 6.3% – 36.0% of the phenotypic variance. Several light responsive QTLs co-located with QTLs for photosynthesis related parameters under various conditions and QTLs regulating biomass and grain weight. These collocated QTL clusters may provide new hints to uncover the genetic control of the acclimation of photosynthesis, biomass, and grain weight to growth light intensity.