Plant & Animal Genome VI Conference

W91

FINE MAPPING OF QUANTITATIVE TRAIT LOCI (QTL) BY HIGH RESOLUTION MOLECULAR MAP IN RICE (Oryza sativa L.)

1. National Institute of Agricultural Science and Technology, Suwon, 441-707, Korea
2. National Honam Agricultural Experiment Station, Iksan 570-080, Korea
3. National Yeongnam Agricultural Expiment Station, Milyang 627-130, Korea
4. Department of Plant Breeding, Cornell University, Ithaca, NY 14853, USA

A molecular map of rice involving 637 of AFLP, SSLP, and RFLP markers has been developed using "MG recombinant inbred population" which consists of 164 F₁₃ lines derived from a cross between Milyang 23 (Tongil type) and Gihobyeo (Japonica type) by single seed descent. The molecular map covers 1,984 cM with an average interval size of 3.1 cM. Using the molecular map we have analyzed quantitative trait loci (QTLs) of agronomic traits, such as yield and yield components, cold tolerance, days to heading, grain characters, blast resistance, shattering habits, panicle length, culm length, and some physico-chemical properties relating to rice quality. A total of 140 QTLs were found from the QTL analysis with 31 agronomic traits; 18 QTLs from yield components and yield; 22 QTLs from grain traits; 34 QTLs from days to heading, culm length, shattering, blast resistance and cold tolerance; 66 QTLs from physical and chemical traits. There were highly significant correlations between yield and grain per panicle, percent grain ratio, and thousand grain weight in the three year data. Yearly variation of QTLs between 1995 and 1996 in Honam region was evaluated. There were yearly variations in the 103 QTLs detected from no. of panicles per hill, ripened grain ratio, yield and so on. However, no variations were detected in the 33 QTLs from 1000-grain weight, culm length, shattering, ash, potassium, adhesiveness, and blast resistance. Yearly variation of QTLs will be discussed with three year data.