DIALLELIC CROSSES AMONG MAIZE LANDRACES FROM YUCATAN AND IMPROVED POPULATIONS

Abstract

The general (GCA) and specific combining ability (SCA) of two diallelic sets consisting of five maize populations each were evaluated. The first set included early mature populations: Nalxoy Blanco, Nalxoy Amarillo, Xmehen-nal from Yaxcabá, V-533 and VS-536. The second included late and early mature populations: Dzit-Bacal from Kantunil, Dzit-Bacal from Presumida, Dzit-Bacal from Bulukax, V-533 and VS-536. Complete randomized blocks designs with four replicates were used, with 10 F1 crosses and five parental populations in each diallel. Data were analyzed using Griffin’s method 2, Model I. For grain yield, in the early mature populations, the GCA effects explained 86% of variation and SCA 14%. VS-536, Nalxoy Blanco and Nalxoy Amarillo populations had GCA’s of 0.21, 0.18 and 0.10. Based on the SCA, the best cross was Nalxoy Blanco x VS-536 (0.27). For grain yield, in the late mature populations,  GCA explained 78% variation and  SCA 22%. The best parent population was Dzit-Bacal from Bulukax (GCA = 0.21), and the best crosses were Dzit-Bacal from Bulukax x VS-536 (SCA = 0.54) and Dzit-Bacal from Kantunil x VS-536 (SCA = 0.10). The most productive populations were the crosses of local landraces and improved populations, proposed as base for plant breeding programs.