R. N. Gadag

Combining Ability for Field Emergence, Kernel Quality Traits, and Certain Yield Components in Sweet Corn (Zea mays L.)

ABSTRACT Sweet corn (Zea mays L.), a specialty corn, has poor field emergence, stand establishment, and low yield compared to field corn, and the latter would be beneficial in the improvement of these traits. Seven field corn and four sweet corn inbred lines were used in a line-by-tester mating design for the analysis of combining ability and heterosis for field emergence, kernel quality traits, and some yield components. Field corn and sweet corn lines differed significantly in flowering, green-ear traits, yield, total soluble solids, and biochemical traits. Field corn inbreds (L5 and L6) and tester T4 emerged as good combiners for early maturity, whereas L2 was a good combiner for yield and sugar content. Testers T2 and T4 were good general combiners for early maturity, green-ear length, total sugar, and non-reducing sugar. Sweet corn recorded higher contents of sugar components and less starch compared with the field corn. Among crosses, L1 × T2, L6 × T4, and L3 × T2 were best specific combiners for early maturity, field emergence, and fresh ear weight, whereas hybrid L7 × T2 had better specific combining ability for grain yield, total soluble solids (TSS), total as well as non-reducing sugars. Further, hybrid L2 × T3 had high per se performance for fresh ear weight (246.67 g) and total sugar (15.49%). Such elite combinations with more fresh harvest yield as well as sugar content can be advanced to select sweet corn lines with improved plant stand and yield, and field corn lines with enhanced sugar content.

Analysis of combining ability in experimental hybrids of Sweet corn (Zea mays var. saccharata)

The GCA and SCA variance in combining ability analysis among the crosses involving 11 sweet corn inbreds was significant for all the traits studied. The additive and non-additive gene effects were found predominant for all the traits. Inbred lines IPSA-8761, IPSA-8761, IPSA-8752, IPSA-8757 and IPSA-8754 were identified as good general combiners for different traits. Specific crosses namely, IPSA-8753 x IPSA-8755, IPSA-8753 x IPSA-8761, IPSA-8754 x IPSA-8758 and IPSA-8756 x IPSA-8758 had significant SCA effects and were identified for various flowering and maturity traits whereas IPSA-8755X IPSA-8758 and IPSA-8754X IPSA-8757 showed significant SCA effect for ear weight with husk, without husk and sugar content. The hybrid IPSA-8753 x IPSA-8759 also showed significant SCA effect for the main sweet corn traits referring to green ear weight without husk and sugar content. These findings could serve as crucial inputs required for improvement of sweet corn.