Genetic divergence among maize hybrids by morphological descriptors

Abstract

Two experiments with 25 maize commercial hybrids were carried out in a direct sowing system in Southern Brazil in the harvests of 2009/2010 and 2010/2011. Quantitative descriptors were used with the objective of determining the genetic divergence and the relative contributions of traits among hybrids for extraction of inbred lines. This study was carried out in Oxisol soil using a randomized block design with four replicates. Data were subjected to combined analysis of variance, and based on the multivariate analyses, Tocher and average linkage (UPGMA) cluster analyses, based on generalized distance of Mahalanobis, to quantify divergence in addition to Singh criterion to validate trait with the most contribution. The multivariate methods were consistent with each other, and the weight of 100 grains was the trait that contributed most to the divergence and had similar behavior in grain yield between hybrids in both years. Furthermore, this descriptor representing significant genetic variability for crossings and lines extraction to hybridization between BM 3061, ATL 200 and P 30B39 Y.

Genetic dissimilarity and definition of recombination clusters among green corn half-sib progenies

“…The UPGMA coupled to the Mojena's criterion, despite the high AER (14.3%), was more sensitive to differentiate the genotypes, forming 11 clusters compared to the 5 ones of the Tocher's method (AER = 5.1%). Similar results were obtained by Rotili et al (2012) and Rigon et al (2015), for the evaluation of corn genotypes, and by Santos et al (2015), for cowpea, confirming the practicality and effectiveness of the method. The UPGMA method clustered the hybrid AG 1051 and the Cativerde 02 variety (control) separately in C I and C IX, respectively.…”

“…On the other hand, the commercial hybrid AG 1051 remained isolated from the genotypes, confirming the high genetic diversity of this genotype in relation to the half-sib progeny analyzed (Table 4). Other studies about genetic divergence by Rigon et al (2015), Santos et al (2015) and Gouvêa et al (2010), using the Tocher's optimization method, reported similar cluster pattern results for corn hybrids, cupuaçu access and rubber tree genotypes, respectively.…”

“…The hierarchical method of average linkage between clusters UPGMA was precise on clusters of green corn half-sib progenies. Rigon et al (2015) studied genetic diversity among commercial corn hybrids and reported that the UPGMA was more sensitive than the Tocher's method. Mohammadi and Prasanna (2003) pointed out that cluster analysis allows to identify genetically more dissimilar genotypes, reducing the required number of combinations in a breeding program.…”

Evaluasi Variabilitas Komponen Hasil Dan Hasil Jagung Manis Generasi S5 Untuk Pengembangan Varietas Yang Beradaptasi Baik Pada Sistem Budidaya Organik

“…Dengan demikian perencanaan hibridisasi menjadi lebih terarah. Hibridisasi antar galur yang berbeda kelompok memungkinkan untuk memperoleh heterosis yang maksimal (Babić et al, 2014;Rigon et al, 2015…”

Research Article Analysis of genetic divergence in sweet corn genotypes through hierarchical optimization methods

“…When evaluating green corn genotypes, Silva et al (2016) verified that the UPGMA method was more sensitive to detect differences between genotypes and consequently to form groups. In contrast, Rigon et al (2015) evaluated only two distinct clustering techniques, suggesting that both (Tocher and Single Linkage) were useful in the study of genetic divergence in corn. Nowadays, the UPGMA method is mostly suggested to study genetic traits of a population (Silva and Dias, 2013); however, the efficiency of other clustering methods to evaluate sweet corn germplasm is unknown.…”