DNA 마커를 이용한 벼멸구 저항성 선발 및 복합내병충성 벼 계통 육성

Marker Assisted Selection of Brown Planthopper Resistance and Development of Multi-Resistance to Insect and Diseases in Rice (Oryza sativa L.)

본 연구에서는 관행의 교배육종과 DNA 마커를 이용한 MAS의 접목을 통하여 벼멸구 저항성과 관련된 단점을 보완하고, 효율적으로 도열병, 줄무늬잎마름병, 흰잎마름병, 벼멸구, 끝동매미충 저항성이 집적된 복합내병충성 우량계통을 육성하고자 수행하였다. 교배모본으로는 완전미율이 높고, 끝동매미충에 저항성인 남평 과 단간이면서 흰잎마름병에 저항성인 주남 을 반복친으로 사용하였고, 벼멸구저항성 유전자 Bph1을 가지고 있지만 간장이 크고 재배안전성이 미흡한 밀양220호’를 공여친으로 사용하였다. 벼멸구 저항성 연관마커 RM28493을 이용하여 BC 1 F 1 및 BC 2 F 1 세대에서 MAS로 저항성 개체 선발과 여교잡을 수행하였으며, 복교잡 F 1 세대에서 MAS를 통한 벼멸구 저항성이 고정된 계통을 선발하였다. 고세대 계통에서 생물검정을 통하여 흰잎마름병, 끝동매미충에 저항성인 계통을 선발하였다. MAS와 생물검정을 통해 도열병, 흰잎마름병, 줄무늬잎마름병, 벼멸구 및 끝동매미충에 저항성인 85개의 복합내병충성계통을 선발하였다. 복합내병충성 계통의 간장, 완전미율 및 수량은 각각 71∼88 cm, 51∼93%, 449∼629 kg/10a 사이에 분포하였다. 복합내충성 계통중 간장, 완전미율 및 수량이 남평벼와 비슷한 계통을 선발하여 ‘밀양265호’로 명명하였다. 최종적으로 본연구에서는 기존의 교배육종과 분자육종의 접목을 통하여 복합내병충성 우량계통을 육성하였으며, 이는 금후 유용교배모본으로 활용 될 것으로 기대된다.

The main objective of this study was to develop the multi-resistance lines to insects(brown planthopper; BPH, rice green leafhopper; GRH) and disease(blast; BL, bacterial blight; BB and rice stripe virus disease;RSV) with good grain quality and plant type by combining conventional breeding and marker assisted selection(MAS) and to eliminate the linkage drag effects between Bph1 gene and culm length, we conducted MAS of Bph1 gene in advanced backcross and double cross progenies. Nampyeong , Junam and Milyang220 were used as the parent in this study. Milyang220 was used as the donor of brown planthopper resistance gene Bph1 with tall culm length. Two backcross progenies were developed using two recipients Nampyeong carrying GRH resistance gene Grh3(t) with good grain appearance and Junam harboring bacterial blight resistance gene Xa3 with short culm length. Two BC1 generations were resulted from the backcrossing of the F1 plants with recurrent parents Nampyeong and Junam . The second rounds of backcrossing(BC2) were derived from the cross of selected resistant BC1F1 plants based on heterozygous genotype of RM28493 linked to Bph1 gene. The double crossed population was constructed from the cross of between each heterozygous BC2F1 plants at RM28493 locus of Nampyeong*3 / Milyang220 and Junam*3 / Milyang220 ., The homozygous alleles in Bph1 gene were selected using co-dominant DNA marker RM28493 in double crossed population. Eighty-five lines with multi-resistance to BL, BB, RSV, GRH and BPH were selected by bio-assay and MAS in generation of double crossing. The culm length, head rice ratio and yield of the selected multi resistance lines was ranged from 71 to 88 cm, from 51 to 93%, from 449 to 629 kg/10a. respectively. We can select a promising multi resistance line similar with Nampyeong of major agronomic traits such as culm legnth, head rice ratio and yield. It was designated as Milyang265. Finally this study was developed the multi resistant varieties against to insects and diseases with the good grain quality Milyang265 by the advanced backcross and double cross combining MAS and it can be used as genetic resources of multi-resistance to insect and diseases in rice breeding programs.