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

Abstract

Popcorn is a popular snack item worldwide. The genetic base of popcorn germplasm is quite narrow, which resulted in limited number of popcorn hybrids. Here, a set of sub-tropically adapted 39 popcorn inbreds of exotic- and indigenous-origin, were characterized using morphological traits and molecular markers for their effective utilization in hybrid breeding. Significant variation for grain popping percentage (GPP: 86.0-98.0%), percent popping expansion (PPE: 1493-3213%) and volume after popping (VAP: 210-315ml) was observed. The mean PPE (2069%) and GPP (93.6%) among popcorn inbreds were higher than the popcorn check variety, VL popcorn (PPE: 1739%, GPP: 92%). Positive correlations were observed among GPP, PPE and VAP. Molecular characterization using 72 SSRs produced 237 alleles with a mean of 3.3 alleles per locus. Polymorphism information content ranged from 0.05 to 0.68, while Jaccard’s dissimilarity coefficients varied from 0.27-0.82. Principal coordinate analysis also depicted diverse genetic nature of inbreds. Cluster analysis grouped the inbreds into three major clusters each having 16, 18 and 5 inbreds. Contrasting inbreds were identified for development of mapping populations to identify loci governing desirable popping quality. The study also identified potential heterotic combinations. The information generated here assumes great significance in breeding for popcorn hybrids.