Bi-parental population for kernel row number: Source for novel genetic variability for yield and yield component traits in field corn (Zea mays L.)

Abstract

Field corn (Zea mays L.) is a vital source of calories for humans, and its demand for food, feed, and fuel is increasing with the global population. To meet these demands, breeders aim to enhance grain yield through genetic improvement. One approach to achieve this is by selecting desirable genotypes in early generations, reducing the need for intense selection in later generations. The utilization of F2 populations for capturing the maximum genetic variability is a promising strategy to expedite the development of improved field corn cultivars. Two F2 populations were generated by crossing a low Kernel Row Number (KRN) parent with two high KRN parents. The populations were evaluated for various yield-related traits, including KRN, kernel number per row, cob length, cob girth, test weight, plant height, cob height, days to 50% flowering, and grain yield. Significant genetic variability was observed for grain yield, plant height, and cob height in both populations, indicating its potential for genetic improvement. Kernel number per row, cob girth, cob length, days to 50% flowering and KRN exhibited lower genetic variance, suggesting the influence of phenotypic plasticity and the presence of both negative and positive alleles. The heritability estimates were high (>60%) for most traits, indicating the predominant role of genetic factors in their expression. Positive correlations were found between KRN and several yield-related traits, such as plant height, cob height, cob girth, and grain yield. These findings highlight the importance of KRN in determining grain yield potential and provide insights into the genetic architecture of the trait.