Breeding of Varieties of Pines Resistant to Pine Gall Midge. (Thecodiplosis japonensis Uchida et Inouye) (II) -Seasonal Variation of Needle Monoterpene Composition in Resistant Pinus thunbergii.-

솔잎혹파리 내충성(耐蟲性) 품종(品種) 육성(育成)에 관(關)한 연구(硏究) -2. 솔잎혹파리 내충성(耐蟲性) Pinus thunbergii의 침엽내(針葉內) monoterpene의 계절적변화(季節的變化)

Employing 7-15 resistant and 8-15 susceptible Japanese black pine (Pinus thunbergii Parl.) trees to pine gall midge (Thecodiplosis japonensis Uchida et Inouye) as samples, needle monoterpenes were analysed by GLC in January and June, and observation was made on the oviposition preference. Following results were obtained. 1. In January, the resistant trees showed higher contents of myrcene, limonene, ${\beta}$-phellandrene and terpinolene but lower contents of ${\alpha}$-and ${\beta}$-pinene and camphene compared to the susceptible trees. But in June, ${\alpha}$-pinene, camphene, limonene, ${\beta}$-phellandrene and terpinolene were higher and the content of ${\beta}$-pinene and myrcene were lower in the resistant trees than the susceptible trees. 2. The content of limonene was higher by the 6.8 percent and the content of ${\beta}$-pinene was lower by the 9.2 percent in the resistant trees than in the susceptible trees in June. 3. No preference for oviposition was found between resistant and susceptible trees. But in the resistant trees gall formation rate was quite lower than the susceptible trees. It was considered, therefore, that limonene and ${\beta}$-pinene content in the needle might be used as an indicator of the resistant Japanese black pine to the pine gall midge regardless of season.

솔잎혹파리 내충성(耐蟲性) Pinus thunbergii의 선발목(選拔木) 7~15개체(個體)와 피해목(被害木) 8~15개체(個體)에 대(對)하여 침엽내(針葉內) monoterpenes 조성(組成)을 1월(月)과 6월(月)에 각각(各各) 조사(調査)하고, 그리고 솔잎혹파리의 산란(産卵) 선택성(選擇性)에 대(對)하여 조사(調査)하여 다음과 같은 결과(結果)를 얻었다. 1. 1월중(月中)에 선발목(選拔木)이 증가(增加)하는 성분(成分)은 myrcene, limonene, ${\beta}$-phellandrene과 terpinolene이고, 감소(減少)하는 성분(成分)은 ${\alpha}$-pinene, camphene과 ${\beta}$-pinene이다. 그리고 6월(月)에 선발목(選拔木)이 증가(增加)하는 성분은 ${\alpha}$-pinene, camphene, limonene, ${\beta}$-phellandrene과 terpinolene이고, 감소(減少)하는 성분(成分)은 ${\beta}$-pinene과 myrcene이다. 2. 6월(月)에 선발목(選拔木)이 피해목(被害木)보다 limonene은 6.8%가 증가(增加)하고, ${\beta}$-pinene은 9.2%가 감소(減少)한다. 3. 선발목(選拔木)에도 피해목(被害木)에서와 같이 상당(相當)한 수(數)의 산란(産卵)을 하나 충영형성율(蟲癭形成率)은 대단(大端)히 저하(低下)한다. 이상(以上)을 요약(要約) 결론(結論)하면 본(本) 연구(硏究)로 Pinus thunbergii 침엽내(針葉內)의 monoterpene 중(中) limonene과 ${\beta}$-pinene의 양성분(兩成分)은 계절(季節)에 관계(關係)없이 내충성(耐蟲性) 검정(檢定)에 유효(有效)하다고 할 수 있다.