Abstract

Demócrito Amorim Chiesa Freitas, SilmarTeichert Peske, Francisco Amaral Villela, Paulo Dejalma Zimmer, Paulo Ricardo Reis Fagundes, Fernanda Plucani do Amaral, Elaine Gonçalves Rech and Geri Eduardo Meneghello

Rice is a model for many genomic studies among crop species. The adaptation to different crop environments is partly the result of traditional breeding combined with molecular assisted selection. Comparative studies between contrasting genotypes can be performed efficiently by the cDNA-AFLP technique, allowing the identification of genes involved in the expression of the target trait. The objective of this study was to identify differentially expressed genes in cultivars contrasting for the character germination at low temperatures. The genotypes used were BRS-Firmeza (Tolerant) and SCSBRS Tio-Taka (Sensitive). Seeds of the two cultivars were sown at 13 and 25°C, respectively. Total RNA was extracted from embryos and cDNAs were synthesized. The cDNAs were analyzed by AFLP (Amplified Fragments Length Polymorphisms) to identify differentially expressed sequences between BRS-Firmeza and SCSBRS Tio-Taka varieties. Four polymorphic fragments were present at 13°C IN BRS-Firmeza molecular profile and absent in SCSBRS Tio-Taka. It is concluded that the technique of AFLP on cDNA as template is efficient to produce and identify fragments of differentially expressed genes in rice during germination under low temperatures.