Testing Early Generation (F ) Maize {Zea mays L.) Inbred Lines for GeneralCombining Ability

摘要

Testing of early generation (F4) inbred lines for general combining ability (gca) enables plant breeders to discard undesirable ones and identify those that are desirable for the production of superior hybrids. In this context, 15 F4 inbred maize lines selected based on narrow anthesis-silking interval (ASI) and high grain yield potential were evaluated for their gca using testcrosses for ASI, cob weight plant~(-1) and grain yield plant~(-1). The analysis of variance for combining ability revealed significant differences among the test crosses for all the three traits. The F_4 inbred lines varied widely for their gca and suggested good ability of testers to discriminate the inbred lines for gca. Five of the 15 F_4 inbred lines were identified as good general combiners for cob weight~(-1) and grain yield~(-1). Non-significant correlation between per se performance and gca effects suggested that per se performance of inbred lines is not a good indicator of their gca effects for any of the three traits. However, significant positive and fairly high magnitude of correlation between per se performance of hybrids and sum of parental gca effects indicated good predictability of hybrids per se performance based on their parental gca effects for all the three traits investigated. Further, significant positive and high magnitude of correlation between parental difference and mid-parent heterosis suggested the need for using diverse parents for maximizing the probability of realizing heterotic hybrids for grain yield of maize.