Comparison of Panicle Length QTL Based on F_2 and F_8 Populations Derived from Rice Subspecies Cross

【Objective】In this study, rice panicle length QTL was analyzed by using F8 RIL population, the similarities and differences of the genetic map, QTL locations, QTL effects in different derivative population of the same parent were compared and the stable expression of QTL of panicle length trait was identified. The results of the study will provide more information about the genetic behavior of rice panicle length and be benefit to the MAS(marker-assisted selection).【Method】A F8 population containing 188 lines, which was derived from the cross between the indica variety Luhui99 and the japonica variety Nipponbare, was analyzed with a genetic linkage map consisting 207 DNA markers. The statistic software of QTL Network 2.0 was applied to detect QTL and QTL effect analysis for rice panicle length. The similarities and differences of QTL mapping and genetic map between F8 and F2population were discussed. 【Result】A total of 7 QTL with significant additive effects were detected on chromosomes 2, 3, 6, 7, 8 and 10 in F8 population. The proportions of phenotypic variance explained by individual QTL ranged from 3.38% to 14.8% and the QTL could jointly explain 52.5% of the total phenotypic variance. There were five same chromosomes having rice panicle length QTL in F8 and F2 genetic map and most of the QTL's physical locations are overlapping or containment. The F8 and F2 genetic maps differed in molecular marker number, marker arrangement, genetic distance and average distance between the markers. 【Conclusion】 Seven rice panicle length QTL were detected in F8 RIL population. Although there were many differences betwen F8and F2 populations in genetic map, QTL analysis and so on, a steady main QTL was found on the sixth chromosome. In addition, four stable rice panicle length QTL were detected in the study which were not reported in previous references.