Production of early maturing heat tolerant wheat varieties for southern warm zone by haploid breeding

Abstract

This research was conducted to compare haploid production methods in wheat using chromosome elimination by wheat and maize crosses. The three methods used were: a) classic b) detached tiller c) intermediary. Parental materials were 11 F1 wheat genotypes (female parents) and maize genotype BC572 (male parent). The traits studied were: seed set, embryo formation, and haploid plant production. The comparison among these methods revealed that the C method was superior with respect to seed set, embryo formation, and haploid production. Overall performance of the three methods was about 76.84%, 25.22% and 51.89% for seed setting, embryo formation and haploid production respectively. Among wheat genotypes DH-133 with 87.28% seed set DH-132 with 32.27% embryo formation and 65.08% haploid production were the best genotypes studied. Considering human resources and glass house conditions all other lines were produced by B method detachedtiller.As far as evaluation is concerned, overall, 1155 wheat lines were evaluated for earliness and heat tolerance. This included 788 lines from international nurseries and local collection and 367 DH lines. The evaluations were conducted preliminary at Karaj and finally at Ahwaz and other tropical sites from 2005 to 2010. Totally, 160 from international nurseries and local collection were identified as early maturing and heat tolerant. These lines will be used as parental materials for DH production in the second phase of the project. From the evaluated DH lines, 21 lined could reach replicated yield trials and finally 6 lines were found to be superior to the check varieties (Chamran and Vee.Nac) both under normal and late sowing conditions at 3 sites namely Ahwaz, Zabol and Darab stations. Three lines of these have already been assessed under farmer conditions at 2 locations and 1 line overyield the best check variety (Vee.Nac) besides being resistant to all kinds of rusts yellow, brown andblackunderlatesowingconditions. * Corresponding Author: Tayebeh Bakhshi  adelehbakhshi@yahoo.com