COMBINING ABILITY FOR NORMAL AND HIGH QUALITY PROTEIN MAIZE SEEDS

Abstract

Association among agronomic field traits and physiological seed
quality and their genetic components are important factors for
broadening germoplasm characterization in a plant breeding program.
This research analyzed the general (GCA) and specific (SCA) combining abilities effects and the genetic action type of agronomic traits and physiological quality of normal and high quality protein seed in maize (Zea mays L.). The genetic material was a group of 14 maize inbred lines, seven of normal grain and seven of high protein quality. The agronomics traits analyzed were: male and female flowering, plant and ear height, plant and ear visual score and grain yield. Physiological quality was determined by initial and final standard germination, initial and final plumule length, and final dry weight. Results showed significative variation among genotypes (P ≤ 0.05) for GCA and SCA effects in all traits. Crosses B-41 x CML-144, CML-144 x CLQ-6203 and LT-154 x CML-177 outstanded by their highest grain yield with 1.39, 1.37 and 1.19 t ha^-1 respectively, while crosses T-45 x CLQ-6203, T-37 x CML-141 and LT-154 x CML-177 had the highest SCA values in final standard germination, with 23.2, 22.9 and 14.2 % respectively. Lines T-45, T-44 and LT-155 showed the highest GCA values for grain yield, with 0.41, 0.78 y 0.45 t ha^-1, while lines CML-144 and LT-155 showed the highest GCA values for final standard germination with 6 % in both cases. The predominating genetic action type was additive for all of the agronomic and physiological traits.