Genetic Characterization Of Early Generation Lines Using SNPS Makers And Agronomic Traits For Resistance To Striga Improvement In Maize

Abstract

The characterization of a greater number of lines hence potentially increase the efficiency of maize breeding programs. This study aims to assess the genetic variation and relationships existing within a population of 177 lines and the two parental lines, using 8,883 SNPs markers obtained from sequencing genotyping (GBS) and four agronomic traits. Two hundred S 1 lines and four checks including the two parents have been evaluated under Striga hermonthica infestation in Benin Republic and Nigeria for two years during 2018 and 2019 growing seasons using 51 x 4 lattice design with two replicates. The UPGMA phylogeny, was used to group the progenies based on their genetic similarity. The tested lines have displayed high genetic variability for all the agronomic traits. Analysis molecular revealed that the polymorphism information content has been varied from 0.047 to 0.50, with average of 0.37, and 63% of the SNP makers were highly polymorphic. The population has displayed a moderate diversity with average genetic diversity of 0.44. The estimated genetic distance has been varied from 0.01 to 0.79 and the highest distance has been observed between the two parental lines. UPGMA clustering based on the Gower dissimilarity matrix grouped the 177 lines into two clusters (I and II) at 30% genetic similarity threshold. The estimated genetic distances between lines showed that all the progenies were genetically related to the two parental lines; and have the potential to provide new favorable alleles for the development of high-performing, Striga-resistant and/or Striga-tolerant maize populations.