Characterization of Oryza nivara introgression lines: A potential prebreeding resource to improve net photosynthetic rate in elite cultivars of rice

Abstract

Photosynthesis is one of the fundamental processes influencing crop growth and productivity. In order to understand better the basis of variation in net photosynthetic rate (PN) and yield potential in rice, two backcross populations derived from Swarna × O. nivara were studied. Gas exchange and chlorophyll fluorescence measurements were taken at flowering stage and data on yield traits at harvest. PN was significantly correlated with stomatal conductance, transpiration rate, mesophyll conductance, carboxylation efficiency, yield per plant (YLDP), and dry mass in both populations. Ten introgression lines (ILs) showed higher PN than their parents. IL 230S showed highest PN with increased YLDP than the remaining ILs. Single marker analysis showed RM514 and RM48 was positively associated with PN and YLDP in popA, whereas RM204 and RM122 in popB. The first 4 principal components contributed 92 and 93% to the total genetic variation in each population, respectively.

Mapping for yield related traits in rice reveals major effect QTL qFLA1.1 from Oryza nivara increases flag leaf area

“…Therefore, photosynthesis was turned out as one good target for breeders to look for lines with high net photosynthetic rate to develop high yielding lines (Teng et al 2004). In our previous study we found that the introgression lines with high net photosynthetic rate showed high yield and total dry mass (Haritha et al 2017(Haritha et al , 2019. In cereals, the top three leaves, particularly ag leaf, is the most essential functional organ to produce a large proportion of photo-assimilates that are later stored in grains (Peng et al 2008 leaf width on chromosomes 1, 2 and 4.…”