MAIZE TESTERS FOR GAMETOPHYTIC CROSS-INCOMPATIBILITY FACTORS

Abstract

In this study we analized the performance of maize (Zea mays L.) inbred lines from different origins, and their crosses as testers, of two cross-incompatibility systems in maize: the gametophyte factor-1 (ga1) and the Teosinte crossing barrier-1 (tcb1). Field experiments were conducted from 2003 to 2006 at Zapopan, Jalisco; at Las Garzas, in Guachinango, Jalisco; and at Tapachula, Nayarit, all of them in México. Seven adapted subtropical inbred lines, three maize accessions with known allelic composition, five commercial hybrids from private institutions, and eleven inbred lines from USA were used. Genetic materials were grouped into three experiments to study the two cross-incompatibility systems. Seed set data was analyzed based on procedures GLM and MIXED of the Statistical Analysis System (SAS). Two single crosses homozygous for Ga1-S were identified as testers for the gametophyte factor-1 (NC354 x W22-P4830 and NC354 x W22-P5270); these crosses proved to have good stability and discrimination capacity. Accessions of the races Maíz Dulce, Dulcillo del Noroeste and Reventador, with Ga1-S allele, allowed the identification of testers for the gametophyte factor-1. No single crosses among adapted and temperate lines with the Tcb1-S allele were useful as testers for the Teosinte Incompatibility Complex.