Yield redutions associated with leaf rust, caused by the fungus Puccinia triticina, are recorded for Brazilian wheat (Triticum aestivum) crops. Incorporation of genetic resistance and knowing the number of genes involved are important tools for plant genetic breeding programs, which are consistently introducing qualitative resistance in cultivars aiming to cope with new races of the pathogen. Biochemical techniques, based upon the analysis of the polymorphism of enzymes, provide a rapid and accurate detection of molecular markers and, also, play a valuable support role in breeding programs for predicting the identification of resistant and susceptible genotypes. The objective of this investigation was to carry out a phytopathological and molecular assessment of the haplodiploid population Trigo BR 35 (resistant)/IAC13-Lorena (susceptible) as to its adult plant resistance to leaf rust, as well as to the genetic similarity available in the progeny haplodiploidized in F1 generation. From a total of 96 double haploid lines evaluated for leaf rust, at adult-plant stage, 29 were resistant, 15 were susceptible and 52 showed less resistance than Trigo BR 35 than that presented by IAC 13-Lorena. The genetic analysis showed that the resistance was due to two partially dominant genes. In the biochemical analysis, made through isoenzymatic esterase system, six bands were detected, all of them anodic and with alpha-esterasic specificity the relative migration varied from 0,09 to 0,69. A high genetic similarity was detected, which confirmed isoesterasic analyses, for the 96 double haploid lines.
Triticum aestivum; Puccinia triticina; esterase; genetic similarity
