GENETIC ANALYSIS OF PROGENIES FROM DIALLEL CROSSES AMONG EIGHT VARIETIES OF DIFFERENT MATURITY GROUPS OF MAIZE (Zea mays L.)

GENETIC ANALYSIS OF PROGENIES FROM DIALLEL CROSSES AMONG EIGHT VARIETIES OF DIFFERENT MATURITY GROUPS OF MAIZE (Zea mays L.)

Abstract:

A full-diallel cross comprising eight varieties belonging to four different maturity groups was developed and studied for fifteen characters to determine general and specific combining ability (GCA,SCA), nature of gene action of parents and hybrids, and heterosis. Eighty one genotypes comprising the crosses, reciprocals, selfs, parents and nine checks were evaluated at Kadawa under irrigation in two different environments (sowing dates). Analysis of variance revealed significant differences for GCA and SCA, indicating presence of additive as well as non-additive gene action. In both environments, the GCA mean squares were highly significant and higher than the SCA mean squares for all traits except cob diameter at environment one, and four traits at environment two. The study revealed significant GCA x environment interaction indicating different parental varieties behaved differently under different environments, hence there is need to select different parental varieties for hybrid production for a specific environment. Significant SCA x environment interaction indicate hybrid performance varies with respect to environments. For that reason, specific hybrids could be produced for specific environments. Sammaz 17 was the best general combiner for both earliness and high yield in environment one while Sammaz 27 was the best general combiner for high yield, earliness and other traits in environment two and across the environments. The crosses which showed significant SCA effect for yield were Sammaz 17 x Sammaz 36 and Sammaz 17 x Sammaz 29. They were from high x low general combiners (Sammaz 17 (high) and Sammaz 36 and Sammaz 29 (low)). These varieties could be exploited for inbred line development to produce commercial hybrids. For earliness and grain yield, Sammaz 19 x Sammaz 27 and Sammaz 36 x Sammaz 29 were the best, they were from low x high and high x high general combiners, respectively. Heterotic patterns observed revealed that at environment one, eighteen hybrids out of twenty eight had positive heterosis for grain yield which ranged from 1.6% to 927.0%. The hybrid Sammaz 36 x Sammaz 35 exhibited highly significant heterobeltiosis for grain yield. Fifteen hybrids out of twenty eight exhibited positive heterosis for grain yield in environment two which ranged from 17.8% to 397.1%. Sammaz 19 x Sammaz 27 exhibited highly significant positive heterobeltiosis for grain yield. High percent heterosis was observed among crosses involving the parents Sammaz 35, Sammaz 36, and Sammaz 27. The results indicate that inter variety hybrid development programme can be an effective breeding approach to exploit the heterotic potential of these varieties.

GENETIC ANALYSIS OF PROGENIES FROM DIALLEL CROSSES AMONG EIGHT VARIETIES OF DIFFERENT MATURITY GROUPS OF MAIZE (Zea mays L.)

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