Genetic Behavior For Yield and its Componemts by Using Full Diallel Crossing and Estimating Drought Tolerance parameters for Maize Inbreds and Hybrids Zea mays L.

Abstract

In order to reach one or more distinct hybrids under irrigation intervals 6 and 12 days of newly derived pure lines, the strength of the hybrid, the effect of the specific camping ability of the union, and the possibility of using selective for drought tolerance, a field experiment was conducted to compare the lines and hybrids of maize for the two seasons autumn 2019 and spring 2020, in the governorate of Anbar / Khalidiyah district, East of Ramadi city. In this regard, five pure lines maize AG116, AG-M20, MH17, MH121 and ZM4 were used and entered into a complete cross-breeding program, full diallel and the behavior of these lines and their reciprocal and hybrids was evaluated according to the first Griffing method and the fixed model. A comparison experiment was carried out between Parental lines, individual and hybrids using the RCBD randomized complete block design, where the main panels were used for the 6 and 12-day irrigation interval, and the secondary panels for genotypes (25 breeds and hybrids) and with three replications. For the two seasons autumn 2019 and spring 2020. The results indicated that there were significant differences between the parental lines and their reciprocal and inverse hybrids in the studied traits. In the two seasons, the reciprocal and inverse hybrids were high (AG116× ZM4) , (AG-M20×MH17) , (MH17×MH121) and (ZM4×MH121). In addition, these two seasons, 6 and 12 days gave a yield of (224.0, 222.8, 217.1 and 201.2) g for the autumn season with an irrigation interval of 6 days and (115.2, 123.2, 114.7 and 121.4) g for the autumn season with an irrigation interval of 12 days, and for the spring season (141.1, 115 and 115). 190.2 and 137.8) g with a 6-day irrigation interval and (100.9, 60.1, 100.1 and 97.4) g with a 12-day irrigation interval for the spring season. The results also showed a significant effect b of general and specific combination ability in most traits, and the parents showed MH17, MH121 and ZM4, the best general combination effect for most of the studied traits. The ratio ( ) was less than one for all the studied traits, the average degree of dominance for the reciprocal hybrids ( ̅) was more than one And for the two seasons, and the degree of dominance for reverse hybrids ( ̅̅̅̅̅̅̅) was more than one in most of the traits. The proportion of heritability in the broad sense was high for all traits and for the two seasons, while the proportion of heritability in the narrow sense was low and medium in cross-hybrids and high in reverse hybrids, especially the 12-day irrigation interval. As for the average irrigation interval of 6 and 12 days, they were significant in all traits. The irrigation interval of 6 days was characterized by the highest average grain yield of 166.28 g, while the irrigation interval of 12 days gave an average grain yield of 76.63 g for the autumn season, while the spring season was characterized by the 6 irrigation interval day by giving it the highest average amounted to 138.09 g, while the irrigation interval of 12 days gave an average grain yield of 75.54 g. The results of field experiments also showed a significant overlap between the two study factors, and the type of interference was the difference in the amount of response and not in the direction of the 5 response. We note that the genotypes G13 (MH121×MH17), G17 (AG116× MH17), G25 (MH121×ZM4), G7 (MH17×AG116), G10 (MH17×AG-M20) and G19 (AG116× ZM4) in the fall season and the genotypes G14 (ZM4×MH17), G16 (AG116× AG-M20), G12 (ZM4×AG-M20), G13 (MH121×MH17), G19 (AG116×ZM4), G20 (AG-M20×MH17), G21 (AG-M20× MH121) and G25 (MH121×ZM4) in the spring season have c the ability to withstand drought and high productivity under stress and non-stress conditions. Drought tolerance indices were used to diagnose drought-tolerant sensitive and drought-tolerant genotypes, as well as principal component analysis and cluster analysis. The results showed that the evidences mean productivity (MP), geometric mean productivity (GMP), and drought tolerance index (STI) are among the best evidence for diagnosing drought-tolerant and sensitive genotypes. Because of its significant correlation with grain yield under stress and non-stress, plant breeders can use drought indices as selectived indices with the genotypes of strains and hybrids to select distinct hybrids.