Genetic diversity and diallel analysis of elite popcorn lines1

Abstract

Popcorn is an important agricultural crop that is consumed as a snack food worldwide. In Brazil, the lack of cultivars with high potential grain yield and popping expansion volume is a vital problem. Therefore, the present study aimed to evaluate the genetic divergence among elite popcorn lines using amplifi ed fragment length polymorphism (AFLP) markers to estimate the general and specifi c combining ability (GCA and SCA, respectively), and correlate the genetic distance with the SCA and hybrid means. For the genetic divergence study, 45 popcorn inbred lines of different hybrids and varieties were evaluated. Subsequently, 10 inbred lines were selected for diallel analysis; grain yield (GY) and popping expansion (PE) were evaluated in three environments. A wide variability of popcorn inbred lines was observed based on the AFLP markers. After evaluating the hybrids, a signifi cant effect was observed for GY and PE, with some experimental hybrids with higher potential GY and PE than the commercial cultivars. From the diallel analysis, a signifi cant effect was observed for GCA for GY and PE; therefore, the lines differed in the frequency of favorable alleles, with promising inbred lines for forming hybrids or synthetic varieties. However, for SCA, no signifi cant effect was observed for these traits. Genetic distance did not correlate with GY and Ŝij, demonstrating an absence of consistency in the prediction of heterotic groups for popcorn using AFLP markers.