꼬마배나무이 (Cacopsylla pyricola)에 저항성 품종육성을 위한 육종재료를 선발코자 월동형 성충수, 단과지내의 산란수, 과총엽내의약충수 및 수관 전체적인 그을음 발생정도를 15개 종 및 종간잡종133개 유전자원을 대상으로 조사하였다. 월동형 성충수는 Pyrus.calleryana 4.6마리, 단과지내 산란수는 P. calleryana 0.3개, 과총엽내약충수는 P. calleryana 0마리, 그리고 그을음 발생정도는 P.betulaefolia, P. calleryana, P. communis, P. hybrid (P.pyrifolia × P.communis), P. lindleyi 0으로 발생 및 피해정도가 가장 낮았으며 종간의 차이가 뚜렷하였다. 전체적으로 대목으로 이용하고 있는 콩배인P. calleryana와 P. betulaefolia가 조사 대상 유전자원 중 가장 높은 항객성(antixenosis)을 보였으나 품질개량에 많은 기간이 요구됨에 따라 실용적으로는 서양배(P. communis) 중 ‘Conference', 'Cascade','Bosc', 'Winter Nelis' 가 가장 낮은 발생 및 피해정도를 보여 꼬마배나무이 저항성 품종 육성을 위한 좋은 육종재료로 판단되었다.

RAPD analysis showed that all the OTUs of 'Sandolbae' were the same species because amplified band patterns of all samples generated by each of 5 random primers were identical. Even though there were different environmental conditions, all the "Chuiangne" trees from three different places were the same species, and also all the "Cheongshilli" trees were the same species too. No genetic variations were detected between native Korean pears grown in the habitats and in the research field. Because 212 polymorphic bands were generated by 9 primers selected through primer screening, they were possible to analyze genetic relationship among naturally growing three native Korean pears and nine cultivars of Pyrus pyrifolia and P. communis. Based on the RAPD analysis, three main groups were formed. The first group represented the Six P. pyrifoia cultivars, the second group was the three native Korean pears, and the last group was the three P. communis cultivars. Genetic distance between 'Wonwhang' and 'Chojuro' was closer than other cultivars in group 1 since dissimilarity index value between these two cultivars was 50.82. However, genetic distance between 'Niitaka' and 'Chojuro' was the most distant compared to the others in group 1. In group 2, 'Sandlobae' was genetically closer to 'Chuiangne' than 'Cheongshilli' because dissimilarity index value between 'Sandlobae' and 'Chuiangne' was smaller, 50.82, than the value between 'Sandlobae' and 'Cheongshilli', 63.636. In group 3, 'Old Home' was genetically closer to 'Bartlett' than 'Kaiser Alexander(or Bosc)'. Group 3 composed of P. communis cultivars was genetically further than other two groups, P. pyrifolia cultivars and native Korean pears.

Five samples (Bakwoonbae, Chungsilbae, Sandolbae, Dolbae, and Chuwhangbae) of Pyrus species differing in their origin of production were analyzed for total phenolic content, vitamin C content, and antioxidant activities. Two antioxidant activities were measured by the free-radical scavenging activity and reducing power method. Total phenolic content of the Chungsilbae extract (20.35 mg/g) was higher than those of other pears. Vitamin C content in five Pyrus species ranged from 420.32 μg/g in Sandolbae to 659.75 μg/g in Bakwoonbae. Chungsilbae also had the highest free radical scavenging activity (76.56%) and reducing power (0.35).