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Genetic Analysis of Crosses among Maize Populations Representing Different Heterotic Patterns
Author(s) -
Mišsević Dragan
Publication year - 1990
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1990.0011183x003000050008x
Subject(s) - heterosis , diallel cross , biology , germplasm , population , inbreeding depression , inbreeding , inbred strain , overdominance , randomized block design , grain yield , agronomy , veterinary medicine , genetics , hybrid , demography , medicine , sociology , gene
Maize ( Zea mays L.) breeders are concerned with the narrowing germplasm base and the wide‐spread usage of a single heterotic pattern. The primary objective of this study was to estimate genetic parameters for a set of seven elite maize populations from the USA, Yugoslavia, and Latin America for selection of base populations in recurrent selection programs. Populations per se, population crosses, populations per se selfed, crosses selfed, and hybrid check B73 ✕ Mo17 were grown in a randomized complete‐block design experiment with four replications at three locations in 1987 and 1988. Contributions of homozygous ( a k ) and heterozygous, ( d k ) loci to population means, mean of random homozygous inbred lines (µ), and heterosis effect ( h kj ) with its subdivisions (average heterosis, population heterosis, and specific heterosis) were estimated. Contributions of heterozygous and homozygous loci to population means accounted for the largest and smallest portions of variation among diallel entries, respectively, for both grain yield and plant height. Heterosis accounted for 11.3 and 8.7% of the total among diallel entries sum of squares for grain yield and plant height, respectively. BS11(FR)C7 had the highest populations per se yield due to its large contribution of both homozygous and heterozygous loci, and the highest estimate of inbreeding depression for grain yield. BSSS(R)C7 had the highest estimate of heterosis effect, but lowest per se yield due to low a k and d k estimates. The highest yield and the highest specific heterosis estimates were found for crosses BS11(FR)C7 ✕ BS16(S2)C3 and BSSS(R)C7 ✕ ZPEP. BSSS(R)C7 ✕ had the highest overall heterosis effect.