Line × Tester Analysis of Quality Protein Inbred Lines of Maize (Zea mays L.)

摘要

In an experiment, 42 topcrosses of 14 Quality Protein Maize (QPM) lines (L1, L2…L14) with 3 testers, viz., CIMMYT QPM pool 17C8, CIMMYT QPM pool 18C8 and DQPMC-1 (T1, T2 and T3) were evaluated against a QPM check, Shakti-1, in a randomized complete block design at G. B. Pant University of Agriculture and Technology, Pantnagar, India during kharif, 2003. Observations were recorded for days to 50% tasselling and silking, plant height, ear height, ear length, ear diameter, kernel rows per ear, 100 kernel weight, grain yield and incidence of banded leaf and sheath blight and brown stripe downy mildew. Protein, lysine and tryptophan contents were also analysed. The characters under study showed highly significant genotypic differences and wide range of variation in mean values. The crosses L8 ×T1, L1×T3, L8×T2, L5×T2, L5×T1, L 1×T1, L13×T3, L3×T1 and L8×T3 revealed significant positive heterosis for grain yield. The GCA effects of the parents showed that L8 was good for ear length, ear diameter, kernel rows per ear, 100 kernel weight and grain yield; L 12 and L13 were the other good general combiners. Based on the SCA effects, L3×T1 and L3×T2 were good for ear length, ear diameter, kernel rows per ear, 100 kernel weight and grain yield; L14×T3, L1×T3 and L4×T1 were the other specific cross combinations good for different characters. Highest heritability was observed for grain yield, followed by ear diameter and ear length. All characters except 50% tasselling and silking showed significant positive correlation with grain yield. Path coefficient analysis revealed that 100 kernel weight had highest direct effect towards grain yield, followed by plant and ear heights.