Production and Evaluation of Agronomic Characters of Introgression Lines from the Cross of Hwaseongbyeo x O. minuta in Rice

Abstract

Wild rices are an important source of useful genes for resistance to diseases, insect pests, tolerance for abiotic stresesand yield increase. O. minuta (BBCC), a tetraploid wild rice having 48 chromosomes, was used for the cross with japonica rices.Fertile introgression lines of BC3F2 to BC5F5 generation were successfully obtained from an interspecific cross between a japonicacultivar, Hwaseongbyeo and O. minuta (AC. 101144). The agronomic performance of F2(BC3F2, BC5F2) and F3(BC3F3, BC4F3,BC5F3) lines were evaluated for yield and yield components and reactions to disease and insect pests. As the backcros and selfedgeneration advanced, the agronomic traits tended to approach to the recurrent parent, Hwaseongbyeo, However, considerable agro-nomic variations were found among the population and agronomically varied lines were produced for all the traits measured.Observational yield test was conducted with 42 selected lines in BC5F5 generation. The overall phenotype of OYT lines resembledto the recurrent parent, Hwaseongbyeo without any wild traits such as grain shattering, long awn and leaf smoothness. The meanagronomic performance showed the improved traits, reduced height, increased spikelet number per panicle, and 1000-grain weight.Especially, the top five high-yielding lines showed 18 to 27% of yield increase, sugesting that positive yield-related alleles fromwild species were combined to the recurrent parent.