Genetic Dissection Of Yield-related Traits Under Different Water Regimes In Maize

Drought is one of the most essential factors influencing maize yield.Improving maize varieties with drought tolerance by using marker-assisted or genomic selection requires more understanding of the genetic basis of yield-related traits under different water regimes.In the present study,213 F_2:3 families of the cross of H082183（drought-tolerant）×Lv28（drought susceptible）were phenotyped with five yield-related traits under four well-watered and six drought environments for two years.Quantitative trait loci（QTLs）analysis identified 133 significant QTLs,including 35 QTLs for ear length,41 for ear diameter,18 for ear weight,15 for kernel weight per ear and 24 for 100-kernel weight based on single environment analysis.The joint-environment QTL analysis detected 25 yield-related QTLs under well-watered environments and nine QTLs under water-stressed environments,suggesting the complicate genetic feature of yield-related traits under drought.Among these joint-environment QTLs,one common QTL（qEL5）was stably identified at both of the water regimes.In addition,qED8,qEW8 and qKW8 were found to be located in the same interval of Chr.8,indicating that one pleiotropic QTL in this genomic region possibly affected ear diameter,ear weight and kernel weight per ear.Similarly,qEL4s and qKW4s were found to be located in the same interval under water-stressed environments,suggesting one pleiotropic QTL controlling ear length and kernel weight per ear.These genomic regions could be candidate targets for further fine mapping and marker-assisted breeding in maize.