벼 종간잡종 근동질계통 이용 저온발아성 및 까락 유전자 분석

Mapping QTLs Controlling Low-temperature Germinability and Awn Using an NILs from an interspecific cross, Oryza sativa×O. rufipogon

Low temperature germination is one of the major determinants for stable stand establishment in the direct seeding method in temperate regions. Quantitative trait loci (QTLs) controlling low temperature germiability (LTG) and awn were confirmed in BC₁F₁ using a near isogenic line (NIL). The NIL was derived from two successive backcrosses of Hwayeongbyeo to one of the RILs derived from an Hwayeongbyeo and O. rufipogon Griff. (Acc. 1944) cross. The BC₁F₁ NIL with the Hwayeongbyeo background possesses six introgressed segments on six different chromosomes from O. rufipogon. BC₁F₂ progenies of the NILs along with Hwayeongbyeo were evaluated for germination ratio at 15℃ for 9 days and awn length for QTL analysis. The germination ratio of Hwayeongbyeo was 56.5% and BC₁F₂ ranged 43%~100%. Awn length was classified as 1-3 degree (1=non, 2=medium, 3=long). Two putative QTLs on chromosomes 1 and 8 were detected for LTG and awn, respectively. The phenotypic variations explained by ltg1 and awn8 were 18.9% and 20.3%, respectively. These QTLs have been detected in the previous QTL or genetic studies. The NILs developed in this study would provide the basis for additional fine mapping aimed at cloning the gene(s) underlying low temperature germinability and awn.