New wheat genotypes tolerant to aluminum toxicity obtained by mutation induction

Seed from the sensitive wheat (Triticum aestivum L.) cultivar Anahuac was t reated to gamma-ray irradiation and eleven Al3+ tolerant mutants selected. The objective was to compare these mutants to the original Anahuac and to t he tolerant wheat cultivars IAC-24 and IAC-60 from 1994 to 1996 in acid (Ca pao Bonito) and limed (Monte Alegre do Sul) soil field trials, in the State of Sao Paulo, Brazil. Grain yield and agronomic characteristics were analy zed. All the mutant lines yielded higher than the sensitive Anahuac cultiva r in the acid soils of Capao Bonito. Under limed soil conditions, 10 mutant s had a similar yield to the original sensitive cultivar and one a lower yi eld. The majority of the mutants were similar in yield to the tolerant cult ivars IAC-24 and IAC-60 under both conditions. Some of the mutants showed a ltered agronomic characteristics, but these alterations did not generally i nfluence the grain yield. The results indicated that tolerant lines with go od characteristics may be obtained from a susceptible cultivar by mutation induction, thus allowing cropping under conditions where Al3+ is a limiting factor.