Breeding Of Rice Blast Resistance Lines With Marker-assisted Selection

Marker-assisted selection (MAS) which is based on genotypic identification and selection by gene-tightly-linked molecular markers is more accurate and efficient than conventional breeding methods. It is also superior in avoiding being affected by other genetic background and environmental factors. Anther culture is the technology to culture the anther which is on a particular developmental stage to obtain homozygous plants. It can shorten the breeding period so it has important application value in rice breeding.This study is aimed to improve the resistance of rice blast of the variety Wuyungeng29196 by MAS and anther culture. We used the variety Wuyungeng29196 as the recurrent parent and chose a blase resistance gene-- Pigm(t) as our desired gene to complete the directional backcross breeding. The results are as followed.1. We used Gumei 4, a variety carrying a resistant gene Pigm(t), as the donor parent. Two closely linked SSR markers, S29742 and RM33-44, were employed to select the Pigm(t) gene in each generation. Finally, a lot of lines were developed from the plants of BC6F2, and many DH (double haploid) selfing lines were chosen from the anthers of BC3F2 in the summer of 2015.2. Among them,59 improved lines with homozygous Pigm(t) were selected. We characterized multiple agronomic traits including grain yield and resistance to rice blast. We finally screened out 13 lines which had increased resistance level and enhanced yield production.3. We also characterized the rice quality of the selected lines and found that 7 of them had similar comprehensive quality with Wuyunjing29196 and some traits were even better than Wuyunjing29196, especially the resistance to rice blast and production. This result reached our expectation.The combination of backcross, anther culture and marker-assisted selection successfully improved the resistance to rice blast, in a shorter breeding period, and could significantly improve the predictability and accuracy. The improved Wuyunjing29196 with high blast resistance level provides important genetic resources in breeding.