Genetic analysis and assessment of stay-green traits in hybrids of temperate and tropical maize germplasm

摘要

Leaf stay-green is a trait in which plants retain leaves with green tissue from flowering through physiological maturity in maize. To assess whether this characteristic improved grain filling in maize, we analyzed five stay-green traits, five grain yield-related traits, and three photosynthetic parameters in 10 hybrids derived from an incomplete diallele cross mating design between five temperate and two tropical maize germplasm inbred lines. The hybrids were grown in three different environments. The degree of stay-green (DSG) was significantly positively correlated with grain yield, ear length, number of grains per row, number of visible green leaves at maturity (MNL), ratio of visible source leaves (RSL), and photosynthetic potential at maturity (MPP). The highest correlation between traits was between RSL and MNL. All five stay-green traits were significantly positively correlated with net photosynthetic rate (Pn). RSL had the highest broad-sense heritability among the stay-green traits evaluated. Our findings suggest that RSL is an important stay-green trait and can be used as a selection criterion for improving stay-green traits in maize breeding programs.