국내 주요 해충인 끝동매미충에 대한 저항성 품종‘청남’은 ‘기누히까리’와 ‘밀양189호’를 각각 모본과 부본으로 인공교배 한 후 약배양으로 육성하였으며, 주요 연구결과는 아래와 같다. 출수기는 평야지 보통기 재배에서 8월 11일로 중생종이며 수당립수는 ‘남평벼’보다 적은 편이고 현미천립중은 무거운 편이다. 불시출수는 발생하지 않았으며, 수발아는 ‘남평벼’보다 약간 높은 편이고, 포장도복은 없었으며, 내냉성은 ‘남평벼’와 비슷하다. 잎도열병 밭못자리 검정 중 정도 저항성을 보였으며, 줄무늬잎마름병과 흰잎마름병(K1, K2, K3)에는 강하며, 바이러스병을 매개하는 끝동매미충에 저항성으로 오갈병에 포장저항성을 나타낸다. 검은줄오갈병에 약하고 벼멸구 등 충해에는 감수성이다. ‘청남’의 끝동매미충 유전분석을 수행한 결과 1개의 단순우성유전자에 의해 지배됨을 확인하였다. ‘청남’의 쌀은 맑고 투명하며 완전미율이 높았으며, 밥맛은 양호한 편이다. ‘청남’의 수량성은 2007년부터 2009년까지 3년간 실시한 지역적응시험 보통기 보비재배 11개소에서 5.43 MT/ha, 이모작재배에서는 5.00 MT/ha, 만식재배에서는 5.18 MT/ha이었다.
Molecular markers are useful tools for evaluating genetic diversity and determining cultivar identity. Present study was conducted to evaluate the genetic diversity within a diverse collection of rice accessions used for Korean breeding programs. Two hundred eighty-seven rice cultivars, composed of temperate japonica, tropical japonica, indica, and Tongil-type of Korean crossing parents were evaluated by means of 15 simple sequence repeat (SSR) markers. A total of 99 alleles were detected, and the number of alleles per marker ranged from 4 to 11, with an average of 6.6 per locus. Polymorphism information content (PIC) for each of the SSR markers ranged from 0.2924 to 0.8102 with an average of 0.5785. These results, with the result that use of only 15 SSR markers made all rice cultivars examined could be uniquely distinguished, imply the efficiency of SSR markers for analysis of genetic diversity in rice. Cluster analysis was performed on similar coefficient matrics calculated from SSR markers to generate a dendogram in which two major groups corresponding to japonica (Group I) and indica and Tongil type rice (group II) with additional subclasses within both major groups. The narrowness of the Korean breeding germplasm was revealed by the fact that most of the Korean-bred and Japan-bred temperate japonica cultivars were concentrated into only 2 of the sub-group I-1 (143 cultivars) and I-2 (58 cultivars) among six sub-groups in major group of japonica. This is because of the japonica accessions used in this study was a very closely related ones because of frequent sharing of the crossing parents with similar genetic background with synergy effect of the inherited genetic difference between indica and japonica. A rice breeding strategy with the use of molecular markers was discussed for overcoming of genetic vulnerability owing to this genetic narrowness.