벼 내랭성 관련 양적형질 유전자좌(QTL) 분석

Abstract

recombinant inbred lines (RILs) derived from the intersubspecific cross between the indica cultivar, Milyang23 and the japonicacultivar, Stejaree45. The RILs were grown in cold-water screening plots to evaluate the effects of the cold water treatment on thecold tolerance-related traits of the rice. Normal distribution of traits such as leaf discoloration, heading delay, culm length reductionand number of spikelets was observed in the RILs, with transgressive segregation relative to either parent. On the other hand, thetraits spikelet fertility reduction and panicle exsertion were continuously distributed and were relatively skewed towards the traitsof the susceptible parent, Milyang23. A linkage map spanning 1,293 cM, with an average interval size of 14.4 cM was constructedusing the markers. No significant QTL was detected for leaf discoloration and heading delay. One QTL each for reduction in culmlength ratio and spikelet fertility, and number of spikelets were detected. Two QTLs for panicle exsertion were detected on chromo-somes 1 and 12, accounting for 5.5 and 5.3% of the phenotypic variance in the trait, respectively. For the 5 QTLs identified in thisstudy, the Stejaree45-derived alleles contributed to desirable agronomic efects. The QTLs for panicle exsertion, reduction in spike-let fertility and spikelet number were on the same location near the SSR marker, OSR20, suggesting the possibility that a single,pleiotropic gene might be controlling these cold tolerance-related phenotypes.