Confirmation of Quantitative Trait Loci (QTL) for spikelets per panicle and awn length using near isogenic lines derived from an interspecific cross between Oryza sativa and O. minuta

다국어 초록 (Multilingual Abstract)

Rice (Oryza sativa L.) grain yield is determined by four yield components: panicles per plant, spikelets per panicle, grain weight and spikelet fertility. Among them, spikelets per panicle (SPP) shows a variation and makes the large contribution to yield output and was the major objective of high-yield breeding. In our previous study, one putative QTL affecting the number of spikelets per panicle (qSPP7) was identified on the long arm of rice chromosome 7 across a 28.6-kb region using near-isogenic lines (NILs) derived from an interspecific cross between the Korean japonica ‘Hwaseongbyeo’ and O. minuta. In the current study, we confirmed this QTL using 540 BC8F2 plants for genotyping and 13 recombinant BC8F3 lines for trait evaluation. The qSPP7 was mapped between two simple sequence repeat (SRR) markers RM4952 and RM21605. The O. minuta segment on chromosome 7 introgressed into the ‘Hwaseongbyeo’ background was associated with an increase in the number of spikelets per panicle. Additional experiment under short-day length condition indicated that NIL-SPP7 was photoperiod sensitive and qSPP7 was not associated with heading date.
Like many other important traits in plant breeding, awn length is also a complex trait controlled by multiple genes. In our previous study, the qawn9 QTL was identified on chromosome 9 in NILs derived from an interspecific cross between Hwaseongbyeo and O. minuta. To continue our previous research, this study was carried out to confirm and narrow down the target region containing the QTL associated with awn length on chromosome 9 using a F2 population derived from a cross between the Korean indica cultivar ‘Milyang 23’ and NIL-Awn9 (derived from a cross between ‘Hwaseongbyeo’ and O. minuta). QTL analysis was carried out to determine the relationship between marker genotype and awn length. We confirmed that O. minuta allele in the target QTL awn9 locus within 96-kb interval between markers VNR10 and RM215 controlled awn development. Thus, the identified QTL and their linked-markers could become a valuable source for the map-based cloning of the gene controlling awn development.

국문 초록 (Abstract)

벼의 수량성은분얼수,수당립수,종자중,종자의 임실률에 의해 결정된다.이 중수당립수는 다양한 변이를 보이고수량 증가에 크게 기여하며, 다수성을 목표로 한 육종에서 매우 중요한 요인이다.이전의 연구에서 한국 자포니카 품종인 화성과 야생벼인O. minuta교배 후대 근동질 계통을 이용하여수당립수를 증가시키는 양적 유전자좌qSPP7(spikelet per panicle)이 7번 염색체 28.6-kb 지역에 위치하는 것을 확인하였다.본 연구에서는 540개의 BC8F2개체의 유전자형을 검정하고 그 중 13개의 BC8F3재조환 계통의 표현형을 조사하여 수당립수를 조절하는 QTL위치를 재확인하였다.qSPP7은 SSR마커인 RM4952와 RM21605 사이에 위치하는 것을 알 수 있었다.화성벼의 유전적 배경에 이입된 O. minuta염색체 단편이 수당립수 증가에 관련있는 것으로 보인다.추가적인 실험에서 단일조건에 NIL-SPP7은 일장감응에 민감한 것으로 나타났으며,이는 qSPP7이 출수기와 연관되지 않음을 의미한다.
식물 육종에 있어 중요한 다른 형질들과 같이 까락길이도 다수의 유전자에 의해 조절된다.선행 연구 결과에서 qawn9는 화성벼와O. minuta종간교잡 후대 근동질 계통에서 탐지되었고,9번 염색체에 위치하는 것을 확인하였다.본 논문에서는 한국 인디카 품종인 밀양23호와 NIL-Awn9 (화성벼와O.minuta교배 후대)를 교배하여 얻은 F2계통을 이용하여 양적유전자좌 범위를 좁히고, 분자 표지를 통해 확보한 유전자형과 표현형과의 관계를 확인하였다. 그 결과 awn9은 분자 표지인 VNR10과 RM215사이에서 확인되었으며,그 거리는 96-kb인 것으로 나타났다.이러한 연구 결과로 통해 밝혀진 양적유전자좌와 연관된 분자 표지들은 까락의 발달을 조절하는 유전자를 밝히는데 유용하게 활용될 것으로 사료된다.

목차 (Table of Contents)

• ABSTRACT
• TABLE OF CONTENTS
• LIST OF FIGURES
• LIST OF TABLES
• CHAPTER ONE: Confirmation of Quantitative Trait Loci (QTL) for spikelets per panicle on chromosome 7 using near isogenic lines derived from an interspecific cross between Oryza sativa and O. minuta
• INTRODUCTION
• MATERIALS AND METHODS
• RESULTS
• DISCUSSION
• CHAPTER TWO: Confirmation of Quantitative Trait Loci (QTL) for awn length on chromosome 9 using near isogenic lines derived from an interspecific cross between Oryza sativa and O. minuta
• INTRODUCTION
• MATERIALS AND METHODS
• RESULTS
• DISCUSSION
• REFERENCES
• KOREAN ABTRACT