Plant & Animal Genome V Conference
Town & Country Hotel, San Diego, CA, January 12-16, 1997.
PAG-V: W65 - COMPARATIVE MAPPING OF QTLS CONTROLLING HEADING DATE IN RICE USING VARIOUS EXPERIMENTAL POPULATIONS
W65
COMPARATIVE MAPPING OF QTLS CONTROLLING HEADING DATE IN RICE USING VARIOUS EXPERIMENTAL POPULATIONS
YANO, MASAHIRO(1), Toshio Yamamoto(2), Yoshihide Kuboki(2), Shao Yang Lin(2), Lisa Monna(2), Takehiko Shimizu(2), Izumi Kono(2), Takuji Sasaki(2)
1. Rice Genome Research Program, National Institute of Agrobiological Resources, Tsukuba, Ibaraki 305 Japan
2. Rice Genome Research Program, Institute of Society for Techno-innovation , of Agriculture, Forestry and Fisheries, Tsukuba, Ibaraki 305 Japan
Mapping of QTLs conferring heading date in rice has been carried out using various experimental population structures derived from a cross between a japonica variety Nipponbare and an indica variety Kasalath. Quantitative trait locus (QTL) analysis based on an F2 population revealed five QTLs located on chromosomes 6, 7 and 8. Five QTLs, which were located on chromosomes 2, 3, 4, 6 and 7, were also identified by QTL analysis of BC1F5 lines. Two major QTLs on chromosomes 6 and 7 were coincident between the analyses of the F2s and BC1F5 lines, however, the locations of other QTLs differed. We are also constructing well characterized genetic stocks, such as near-isogenic lines, carrying one or multiple chromosomal segments of the parental line, Kasalath, in the genetic background of the other parental line, Nipponbare. An additional locus controlling heading date has been identified using a BC3F2 segregating population. A epistatic interaction between the newly identified gene on chromosome 3 and the gene at the major QTL on chromosome 7 was observed. These comparisons between identified QTLs for heading date suggest that the potential for QTL detection using a primary segregating population, such as an F2 or recombinant inbred line, is limited. Thus, development of various types of population structures, such as a series of isogenic lines or substitution lines, will be necessary to identify most loci, including QTLs with epistatic interactions.