cDNA-AFLP na identificação de genes relacionados a qualidade fisiológica

Abstract

Some studies have reported the existence of contrasting soybean genotypes for seed physiological quality. Differences such as presence of seeds with total or partial impermeability for water absorption through the seedcoat make them less susceptible to mechanical damage, adverse weather and deterioration. The semi-permeable seed coat trait can be used in soybean crop breeding programs to be incorporated in genotypes with high production. However, is necessary to characterize genes involved with the trait. Molecular biology tools, such as the cDNA-AFLP technique, can be used to identify genes involved in seed physiological quality. The objective of this study was to evaluate the efficacy of the cDNA-AFLP technique to obtain gene fragments differently expressed among soybean seedcoats with contrasting permeability. Seeds from two genotypes, CD-202 (susceptible to deterioration and permeable yellow coat) and TP (resistant to deterioration and semi-permeable black coat) were produced in greenhouse under homogeneous conditions. Seeds were harvested at different times (25, 30, 35, 40 e 55 days after anthesis). The total RNA was extracted using Pure Link Plant RNA reagent. The Double Stranded cDNA Synthesis Kit was used to obtain cDNA double strand. The AFLP technique was applied and 64 primer combinations were tested. This tool permitted the identification of 47 gene fragments differently expressed among coats from the two genotypes and was shown to be an efficient alternative to studies related to the identification of genes involved in seed quality.