Heritability and correlation among some selected morphological traits and their relationship with fall armyworm damage in sweet corn.

Fall armyworm [Spodoptera frugiperda J. E. Smith] (FAW) is a serious pest in field corn and sweet corn [Zea mays L.] in many parts of the world. Sweet corn germplasm with effective levels of resistance to damage by the fall armyworm is needed to transfer resistance to commercial hybrids. The objectives of this study were to estimate heritability and to estimate the correlation among some selected morphological traits and their relationship with FAW damage. Seven shrunken-2 (sh2) inbred lines and four commercial sh2 hybrids of sweet corn were crossed to Mp708, a FAW-resistant field corn line. The F2 populations were subdivided with one half being selected for the sh2 trait and the other half was left unselected. Parent, F2, and F3 populations were artificially infested with FAW and evaluated for leaf damage caused by FAW. Heritability estimates for FAW resistance ranged from 0.22 to 0.61 depending on method of estimation used. The highest correlations occurred between silk color and anther color (0.70) and silk color and glume color (0.49). There were no consistent correlations of most morphological traits with FAW damage. A linkage between white silk and shrunken-2 was observed.