Research Article Evaluation of genetic variability to form heterotic groups in popcorn

Abstract

In view of the narrow genetic base of popcorn, probably due to its evolution by selection from flint maize types alone, knowledge about genetic divergence is imperative for the formation of heterotic groups. Thus, our objective was to identify heterotic groups of popcorn lines; we did so by exploiting the representative genotype collection of the Active Popcorn Germplasm Bank of the State University of Northern Rio de Janeiro. Thirty-eight popcorn genotypes from different origins were analyzed by two methodologies to identify divergent groups. In the first method, the genotypic data were processed to determine the number of groups, based on Bayesian clustering algorithms, and two clustering methods (UPGMA and Ward), based on three genetic distance algorithms, weighted index, unweighted index, and an index of genetic distance or dissimilarity, proposed by Smouse and Peakall. The second methodology identified groups based on simultaneous use of morphoagronomic and molecular information and extracting the genetic distance matrix by the Gower algorithm, and later applying UPGMA and Ward clustering methods. The consistency of the clustering methods was evaluated by cophenetic correlation coefficients. The significance of these coefficients was examined by the Mantel test. There was significant genetic variability among corn popcorn accesses at morphological and molecular levels. There also ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 17 (3): gmr18083 C. Vittorazzi et al 2 was agreement between multivariate clustering techniques, mainly when using genotypic data provided by microsatellite markers. heterotic groups were identified; these were formed mainly according to the origin of each genotype and/or geographic origin. We found that there is sufficient heterosis to develop new cultivars.

Combined Dominance and Additive Gene Effects in Trait Inheritance of Drought-Stressed and Full Irrigated Popcorn

“…In a first instance, crosses between parents with a good performance for grain yield and its components (P3, P6, and P7 with L71), may be promising. In genetic diversity studies, estimated by microsatellite markers (SSR-EST), the largest genetic distances were found between P6 and L71 [8,45], indicating a better chance for allelic complementation. Hybrids resulting from the combination of these parents can have high performance for both popping expansion and grain yield.…”

Can Genetic Progress for Drought Tolerance in Popcorn Be Achieved by Indirect Selection?

“…Consequently, the exploitation of variability in popcorn becomes fundamental to access so far unexplored sources of drought tolerance in plant breeding. For this, the North Fluminense State University "Darcy Ribeiro" (UENF) has a germplasm collection containing accessions from temperate and tropical climatic adaptated regions of Latin America, as well as inbred lines from improved elite materials in Brazil [13]. In this regard, a better understanding of the morphoagricultural and physiological responses of plant genetic resources is required and some strategies to optimize plant selection in water-deficit environments are proposed.…”

Genetic variability of popping quality traits and microsatellite-based characterization of popcorn inbreds for utilization in breeding programme

“…Inbreds with contrasting popping attributes can be used to identify the loci for further improvement by developing segregating mapping populations. Vittorazzi et al (2018) has reported sufficient genetic variability at phenotypic and genotypic levels among the 38 popcorn genotypes. Babu et al (2006) mapped QTLs for popping quality traits using popcorn × flint corn, while Lu et al (2003) and Jain-Poster and Thomas (2015) identified QTLs through mapping population developed from popcorn × dent corn.…”

“…The recent initiatives under the maize breeding programme in India have led to the development of new sub-tropically adapted diverse popcorn inbreds from exotic-and indigenous-sources. Characterization of these newly available inbreds and understanding their genetic relationships therefore hold immense significance for their utilization in the breeding programme (Devi et al 2017, Vittorazzi et al 2018). Molecular markers have often been utilized for accurate measurement of genetic relationship due to their abundance, whole genome coverage and environment neutral behavior.…”