Journal of Environmental Biology

Agronomic characters and genomic markers based assessment of genetic divergence and its relation to heterotic performance in maize

Paper received: 18.08.2018??????? ???????????? Revised received: 28.12.2018??? ??????????????????? Re-revised received: 25.01.2019???? ?????????????????? Accepted: 29.01.2019

Authors Info

Punya¹, V.K. Sharma¹*,

P. Kumar¹ and A. Kumar² ?

¹Department of Agricultural Biotechnology and Molecular Biology, Dr. Rajendra Prasad Central Agricultural University, Samastipur, Pusa-848 125, India

²Department of Plant Breeding and Genetics, Dr. Rajendra? Prasad Central Agricultural University, Samastipur, Pusa-848 125, India

*Corresponding Author Email :

vksharmarau@gmail.com

Abstract

Aim: The present study was undertaken to examine the relation between genetic divergence of some tropical inbred lines of maize and extent of heterosis manifestation in their single cross hybrids.?? ???

Methodology: Fifteen inbred lines and three inbred testers along with 45 single cross hybrids were evaluated by adopting randomized complete block design during two seasons. The observations recorded on eight metric traits of the entries in each of three replications were utilized during statistical analysis across the seasons. Relative importance of classification variables was determined by principal component analysis and the phenogram was generated using average taxonomic distance. Molecular profiling of inbred lines was carried out by employing 28 SSR primer pairs covering all the chromosomes. Principal coordinate analysis was performed and similarity indices based dendrogram was constructed. Relationship between parental genetic divergence and heterosis was statistically tested.

Results: Significant differences due to parents, hybrids and parent vs. hybrids were observed for all metric characters. Principal component analysis based diagram and average taxonomic distance based phenogram separated the inbred lines into five clusters. Amplification profiles based principal coordinate analysis and hierarchical cluster analysis differentiated the inbred lines into four major clusters. Statistically non-significant correlation of genomic data based genetic similarity or phenotypic data based genetic dissimilarity of inbreds was revealed with grain yield and heterosis of hybrid combinations. Significantly positive correlation was found between heterosis over mid parent or better parent and grain yield of hybrids.? ???    

Interpretation: Parental genetic divergence was not linearly or additively related to heterosis manifestation in hybrid. Moderate genetic divergence together with high per se performance of inbreds seemed to be a better criterion than consideration of merely extreme genetic diversity as the basis for the choice of parental inbreds during heterotic single cross hybrid development in maize.

Key words: Genetic diversity, Genomic markers, Heterosis, Maize, Principal Coordinate Analysis

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