Genetic diversity of sweet corn inbreds using agro-morphological traits and microsatellite markers

Abstract

Assessment of genetic diversity is a pre-requisite to broaden the genetic background of cultivated base of sweet corn, an endosperm mutant of field corn that alters starch biosynthesis pathway in endosperm. In the current investigation, genetic divergence among 39 inbred lines was assessed on the basis of 14 agro-morphological traits, two quality parameters and 63 microsatellite markers, selected on the basis of their association with QTLs affecting kernel quality. The cluster analysis based on unweighted pair-group method using arithmetic averages for agro-morphological and quality traits grouped the 39 inbreds into three clusters with 5, 14 and 20 genotypes, respectively. The unweighted neighbor-joining method for microsatellite markers also categorized the inbred lines into three major clusters grouping 10, 9 and 20 genotypes in cluster I, II and III, respectively. The two cluster distribution patterns showed approximately 36 percent similarity. The assay of 30 microsatellite repeats identified 82 alleles with allele size ranging from 80 to 400 bp. The major allele frequency and PIC value of the markers ranged from 0.42 to 0.79 and 0.27 to 0.63, respectively, which suggested the presence of high amount of polymorphism among the inbreds. The average heterozygosity was recorded to be 0.19 which signifies proper maintenance of inbred population. Principle co-ordinate analysis also depicted diverse nature of inbred lines and agreed well with the previously determined clustering pattern. This study has identified several inbreds, having good yield and high sugar content which will not only enhance the genetic background of sweet corn germplasm but will also lead to development of high-yielding hybrids with improved quality.

Identification of Gene Associated with Sweetness in Corn (Zea mays L.) by Genome-Wide Association Study (GWAS) and Development of a Functional SNP Marker for Predicting Sweet Corn

“…Molecular markers are used for the characterization of germplasms, identification and mapping of genes and QTLs for various agriculturally important traits in maize [ 31 , 32 , 33 , 34 , 35 , 36 ]. A previous study identified four simple sequence repeat (SSR) markers linked to the sh2 gene via bulk-segregant analysis (BSA) in three mapping populations [ 37 ].…”

Genetic variability, heritability and genetic advance in shrunken-2 super-sweet corn (Zea mays L. saccharata) populations

“…Super-sweet corn has a narrow genetic base (Tracy, 2001;Teixeira et al, 2013;Mahato et al, 2018) and possesses some undesirable characteristics, such as poor field emergence and seedling vigour and susceptibility to diseases and pests. In addition, tropical climatic conditions are characterized by high disease incidence, pest attack, short day length, and high temperatures.…”

Marker-assisted pyramiding of γ-tocopherol methyltransferase and glutamate formiminotransferase genes for development of biofortified sweet corn hybrids

“…The strategy allows for biofortification in elite F 1 hybrid with much higher efficiency and accuracy. A further improvement of this strategy could be achieved by integrating morphological traits assay to characterize genetic structure of parent lines comprehensively ( Mahato et al, 2018 ). Further, the development of new polymorphic detection technologies such as KASP ( Semagn et al, 2014 ), and whole-genome resequencing ( Jiao et al, 2012 ; Mace et al, 2013 ) would also greatly expand the utility of this strategy.…”