Diallel analysis and inbreeding depression of commercial maize hybrids aiming the formation of base populations


The development of base populations derived from high yield commercial hybrids is considered one of the main strategies to initiate a maize breeding program, mainly because these hybrids have already been tested in many environments, and so, associating high yield and a large proportion of favorable loci fixed. Therefore, the objective of the present study is to estimate the combining abilities and inbreeding depression of commercial maize hybrids for agronomic traits. Eighteen commercial hybrids divided in two groups accordingly to their respective companies, seventy-two F combinations from a partial diallel scheme, eighteen S populations and one check were evaluated in a randomized complete block design in two experiments, both in Sementes Balu Experimental Unit, Sabáudia (PR), Brazil, for growing seasons from 2011/2012 and 2012/2013. The Griffing method (1956), adapted to a partial diallel by Geraldi and Miranda Filho (1988) was applied for the evaluation of the general com- bining ability (GCA) and specific combining ability (SCA). The hybrids P1630, P4285, 30B39Y and DKB370 showed increased yield, and hybrids P1630, 32R22H, and DKB615 showed reduced plant and ear height. These hybrids can be recommended for the extraction of inbred lines and formation of composites followed by intrapopulation selection. The combinations P1630 x DKB330, P4285 x DKB245, 30F53 x DKB370, and 32R22H x DKB370 showed desirable SCA effects for grain yield and are recommended for use in interpopulation breeding programs. Among the hybrids with desirable GCA effects, 30B39Y showed the lowest inbreeding depression effect for the analyzed traits.


Zea mays L, base populations, combining abilities, heterosis

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Maydica - A journal devoted to maize and allied species

ISSN: 2279-8013