Construction Of An Sslp Linkage Map And Mapping Of Qtls Underlying Grain Traits In Rice

A microsatellite linkage map of rice was constructed based on a doubled haploid population consisting of 86 lines and was employed to map QTLs underlying brown rice length (BRL), brown rice breadth (BRB) and brown rice weight (BRW). The population was generated by anther culture of Peiai64s/E32, a two-line hybrid rice variety with high heterosis. 149 pairs of published PCR primers for amplifying microsatellite or simple sequence repeat (SSR) loci were used for the study. 56 of them displayed polymorphism between the two parents, and therefore were used for genotyping of the DH lines. Marker-type data of these 6 chromosomes together with those of the other 6 chromosomes of odd members provided by another student were analyzed using the software MapmakerlExp 3.0 to construct a whole genome map. The map contains 124 SSR markers and covers a total length of 801.7 cM with an average distance of 6.74 cM between adjacent markers. The partial map of the 6 chromosomes of even numbers contains 56 loci and has a total length of 386.7 cM with an average distance of 6.91 cM between adjacent markers. The partial map has a familiar marker order to the map published by Temnykh et al with only a few reversions, but is much shorter than the Temnykh?s map. QTL mapping was conducted with the whole genome map using the method of composite interval mapping. 18 QTLs were detected, 8 for BRL, 4 for BRB and 6 for BRW, which could explain 78.61%, 68.62% and 72.06% phenotypic variances of BRL, BRB and BRW, respectively. The location of several QTLs, particularly those with larger effects, are consistent with preveous reports of other researchers.