Quantitative Genetic Analysis of Chlorophyll during Dark-induced Senescence at Seedling Stage in Recombinant Inbred Line Population of Maize

Chlorophyll is an important pigment that is involved in the process of photosynthesis in plants and some algae.Different photoperiods and chlorophyll contents affect grain yield and plant health.In the present study, one recombinant inbred line (RIL) population constructed by using Zong3 and Yu87-1 was used for quantitative genetics analysis of chlorophyll content before and after dark treatment at the seedling stage.Chlorophyll index of the first and second leaves of six plants from each line were measured with SPAD-502 before and after dark treatment.A total of 19 putative quantitative trait loci (QTLs) were identified with each accounted for 6.87-15.9% of the observed phenotypic variation.Moreover, eight major putative QTLs that explained more than 10% of the observed phenotypic variation were identified.In addition, one QTL located on chromosome 3, which affected DF (SPAD value at the first leaf after dark treatment) and LF (SPAD value at the first leaf before dark treatment) was co-localized with a candidate gene (GRMZM2G170013 translated into chlorophyll b reductase) of the chlorophyll pathway.These results help better understand the genetic background of chlorophyll during dark-induced senescence and photoperiodic variations.