Genetics of characters associated with drought resistance in maize (Zea mays L.)
1996
Chen Zehui
Correlation analysis showed that under drought condition, leaf rolling rates, stomatal conductance, anthesis-silking interval, number of leaves, plant height, harvest index and leaf angle were associated with drought resistance. Estimates of genetic components showed that under drought condition, additive effects were important in ear length, ear diameter, 100-seed weight, plant height, kernel rows, number of leaves, leaf angle and shoot dry weight. Dominance gene effects were important in controlling the inheritance of ear length, plant height and ear diameter. Ear length, ear diameter, 100-seed weight, number of kernel rows, plant height and shoot dry weight exhibited over dominance. Grain yield and leaf area appeared to be controlled by epistasis. The study also revealed that the magnitude of additive gene effects decreased under drought stress condition. Heritability estimates (narrow sense) were high for number of leaves (0.8752) and leaf angle (0.70830), moderately high for kernel rows (0.5021), moderately low for shoot dry weight (0.3883), 100-seed weight (0.2489) and low for plant height (0.15460), ear length (0.1211) and ear diameter (0.1181). Estimates for heritability were lower under drought stress than under irrigated condition. Under drought condition, inbred lines IS62, LB110 and IS75 had higher GCA effects in most characters associated with drought resistance. LB146 exhibited higher GCA effects in ear diameter and 100-seed weight. The crosses LB110 x IS75, LB110 X LB146 and IS75 x IS62 exhibited the three highest SCA effects for grain yield. These inbred lines and crosses were primarily recommended for drought resistance breeding program
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