Estimates of genetic selection gain in irrigated F3 rice families
Rice production estimate in Brazil is 10.7 million tons, of which approximately 80% comes from the flood irrigation system in the southern region. Rice breeding programs have an important role in the development of cultivars with high production potential and industrial quality. This study estimates variance components and genetic parameters in F3 families, and predicts the genetic gain in rice grain quality for the F4 generation. We used fifty-six (56) F3 families obtained from the advance of generations of the hybrid BRSCIRAD 302. This hybrid was selected for its traits of agronomic and scientific interest, such as grain yield and industrial yield. The hybrid was developed by Embrapa in partnership with CIRAD (Center for International Cooperation in Agronomic Research for Development) for Rio Grande do Sul State through the crossing of CIRAD 464 (M) × SBT 106 (F). The quality of the selected families was analyzed for amylose content, white belly, and gelatinization temperature. The F3 families showed low gelatinization temperature. Selection of BRSCIRAD 302 hybrid families with smaller white belly spots and higher amylose content may be more successful if carried out between F3 families. Twenty-two (22) families showed amylose content higher than that of the highest parent (29.44%). The predicted genetic gain in amylose content was 4.85% for families derived from the hybrid BRSCIRAD 302.