Heritability estimates for yield and related traits based on testcross progeny performance of resistant maize inbred lines

摘要

This research aimed at investigating "Heritability estimates for yield related traits based on testcross progeny performance of resistant maize S, inbred lines". It was conducted at Agricultural University Peshawar (AUP) and Cereal Crop Research Institute (CCRI), Pakistan. During the spring crop season (March-June), 42 selected S, lines resistance to southern leaf blight were crossed to a single-cross tester WD 2x8 in isolation for evaluation of early generation testing. After discarding nine testcrosses for absence or low seed set, 33 testcrosses along with three checks were evaluated using randomized complete block design with three replications at AUP and CCRI during summer crop season (July-October). The data revealed that testcrosses were highly significantly different for all the characters studied, while significant differences were observed for ear length and prolificacy. The genotypexlocation interaction was also highly significant for most traits except ear length and prolificacy, which were nonsignificant. Mean values for grain yield, 1000 kernel weight and kernel row ear~(-1) were 6939 kg ha~(-1), 307.8 g and 14.4 g, respectively. Maximum grain yield (9178 kg ha~(-1)) was produced by TC-10, while the minimum grain yield (4425 kg ha~(-1)) was observed for WD 3x6, which was used as a check. In all the three checks, mean values for all the yield contributing traits were considerably lower than almost all of the test crosses. The grain yield of checks, which ranged from 4425 to 6976 kg ha~(-1), was considerably lower than 9178 kg ha~(-1) for TC-10, 8518 kg ha~(-1) for TC-21 and 8307kg ha~(-1) for TC-3. All the testcrosses had greater yield than WD 2x8 (F_2) and WD 3x6, while WD 2x8, a single cross hybrid, had less or almost equal yield to most of the testcrosses. Maximum (>60%) heritability was observed for grain yield, 1000 grain weight and kernel rows ear~(-1);while moderate (>30%<60%) heritability was recorded for ear length, grain moisture at harvest and prolificacy. Our results suggested that early generation testing is a pivotal method for plant breeders to discard undesirable materials while generating inbred lines for the production of hybrid.