Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: January 1, 2000
Publication Date: June 15, 2000
Domestication of plants for agricultural use has brought about profound genetic change in ancestral plant species. Intensive, scientific breeding of crop varieties by modern plant breeders over the last century hs narrowed the gene pool in many crops. Many wild ancestors of modern crop plants can still be found in their natural habitats and have been collected and maintained in national and international germplasm collections. These collections offer the possibility of abundant genetic variation that may be useful in breeding programs. A new advanced backcross breeding strategy that utilizes molecular linkage map data has been developed as a means of incorporating useful genes from wild ancestors. Rice breeding programs located in China, Indonesia, Korea, Colombia, Brazil, Ivory Coast and the USA participated with researchers at Cornell University to test this new breeding method. A crossing program was initiated using high yielding local varieties and three wild ancestors of rice. Segregating progeny from backcross populations (BC2) were evaluated in the country of origin for various yield and agronomic traits and quantitative trait loci (QTL) were determined at Cornell for each breeding population. More than half of the QTLs from crosses made with Oryza rufipogon species exhibited a positive effect. In particular, genes located on chromosome one were found to positively influence height, grains per plant, and grain weight across several of the rice populations. Although results from the other two wild species are still pending, these observations indicate that wild ancestors may contribute genes that will be commonly useful to breeding programs around the world.