Avoidance of Linkage Drag Between Blast Resistance Gene and the QTL Conditioning Spikelet Fertility Based on Genotype Se
Previous study showed that a linkage drag between a blast resistance gene Pi25(t) and QTLs conditioning spikelet fertility (qSF-6) and number of filled grains per panicle (qNFGP-6) was detected on the short arm of chromosome 6. A larger population was used for further verification, and the results confirmed the linkage drag between the blast resistance gene and QTL conditioning spikelet fertility, other than QTL conditioning number of filled grains per panicle. Breakdown or avoidance of the linkage drag could be achieved by selection against the genotype background of a heading-date gene (qHD-7) that resided in the region between RM2 and RM214 on chromosome 7. For further validation, two lines with almost identical genotypes on all chromosomal regions except the Pi25(t) region on chromosome 6 were chosen to develop a new population. The results showed that qSF-6 could be further subdivided into qSF-6-1 and qSF-6-2. When the genotype of the region between RM2 and RM214 was from rice variety Zhong 156, the linkage drag between Pi25(t) and qSF-6-2 was detected and the allele of qSF-6-2 from rice variety Gumei 2 reduced the spikelet fertility. When the genotype of the region between RM2 and RM214 was from Gumei 2, no linkage drag was detected. This indicates that the linkage drag between the blast resistance gene and the QTL conditioning spikelet fertility could be broken down or avoided under a certain background genotype selection against heading-date and provides a marker aided solution for high level of blast resistance and yield breeding in rice and other crops as well.
作 者： LIU Wen-qiang FAN Ye-yang CHEN Jie SHI Yong-feng WU Jian-li 作者单位： Chinese National Center for Rice Improvement/State Key Laboratory for Rice Biology, China National Rice Research Institute, Hangzhou 310006, China 刊 名： 水稻科学（英文版） 英文刊名： RICE SCIENCE 年，卷(期)： 2009 16(1) 分类号： S5 关键词： rice (Oryza sativa) linkage drag blast resistance quantitative trait locus spikelet fertility heading date