COMBINING ABILITY AND GENETIC PARAMETERS FOR CYTOPLASMIC MALE STERILITY LINES IN Zea mays L.

Abstract

This study aimed to evaluate The number of pure inbred lines of maize (Zea mays L.) carried out for two seasons (spring and autumn) of 2019 in the fields of the research station/ agricultural research station in Abo Gharib. Four cytoplasmic male sterile inbred lines (A1, A3, A5 and A7) with their maintenance lines and four genetically fertile inbreds ( Inb2, HZ3, R5 and 18) in addition to the control hybrid (Nahrain) were used. Single hybrids were produced according to line × tester system. All genotypes were planted using randomized complete block design (RCBD) in three replicates, to analyses general and specific combining ability and estimate the effects and estimation some genetic Parameters for number days of sowing to 50%, leaf area, rows number per ear, kernels number per row , 500-kernel weight and grain yield per plant. Comparison results showed that inbred lines and their single crosses presented significant differences for all studied traits. The hybrids (A1×HZ3), (A1×R5) and (A3×HZ3) scored highest yield (175.1, 172.2 and 172.1) respectively. Obtained results also recorded significant influence of GCA and SCA in most studied traits, And the values of GCA/SCA was less than one, And the percentage of broad sense heritability was high for all traits, while it was low for the narrow sense heritability for all traits as well, which led to a higher average degree of dominance than the correct one, which indicates that the traits were under the influence of the dominance and over dominance of genes, which indicates that the possibility of using superior parents in their speculations to derive Single hybrids with special combinability of field characteristics, yield and components.