Genetic base of Brazilian irrigated rice cultivars

• Main Authors: Hudson de Oliveira Rabelo, João Filipi Rodrigues Guimarães, José Baldin Pinheiro, Edson Ferreira da Silva
• Format: Article
• Language: English
• Published: Brazilian Society of Plant Breeding 2015-08-01
• Series: Crop Breeding and Applied Biotechnology
• Subjects: Oryza sativa; relative genetic contribution; accumulated genetic contribution; genealogies; genetic vulnerability
• Online Access: http://www.sbmp.org.br/cbab/siscbab/uploads/c8eb9792-b0a1-dcda.pdf

The aim of this study was to estimate the genetic base of Brazilian irrigated rice cultivars released in the period from 1965 to 2012. The genealogies of the cultivars were obtained based on information from marketing folders, websites, crossings records, and scientific articles. The following factors were calculated: relative genetic contribution (RGC), accumulated genetic contribution (AGC), frequency (in percentage) of each ancestor in the genealogy (FAG), number of ancestors that constitute each cultivar (NAC),number of ancestors responsible for 60%, 70%, 80% and 90% of the genetic base (NAGB), and average number of ancestor per cultivar (ANAC). The cultivars were also grouped based on the period of release (1965-1980, 1981-1990, 1991-2000 and 2001-2012). For each grouping, the previously described factors were also estimated. A total of 110 cultivars were studied and it was concluded that the genetic base of Brazilian irrigated rice cultivars is narrow.