Mosaic disease of black locust(Robinia pseudoacacia L.) I. Symptom and transmission by grafting

아까시나무모자이크병에 관한 연구 I. 병징 및 접목전염

Symptom of the mosaic disease of black locust which is presently widespread in Korea was observed and transmission of the disease was investigated by means of grafting Since its symptom was typically mosaic and its transmission was easily accomplished, the disease was considered to be caused by a virus. In investigation of transmission by grafting, it was found out that the discase was easily transmitted in both of the following cases, i. e., healthy seedlings grafted with diseased scions and diseased roots with healthy scions. In the healthy seedlings plus diseased scions grafting, some grafted seedlings were purposedly deprived of the diseased scions after, a certain length of time(10∼30 days), while some were left grafted. The former case showed much higher transmission rate than the latter case, but no fluctuation in rate of transmission by the length of contact period(10-30 days) was recognized. And even when the union between stock and diseased scion by callusing was not successful, the transmission was withnesed. On the basis of the symptom, transmission by grafting, and possibility of transmission by sap inoculation(not published yet), it is supposed that the mosaic virus belongs to the group of the black locust mosaic virus that has been reported in southeastern Europe by Atanasoff(1935) and Milinko et al(1961). It is very likely that the witches' broom of black locust recorded by Myung-O Kim et al(1961) in Korea is the mosaic disease.

한국 전역에 널리 발생하는 아까시나무의 모자이크병에 대해서, 그 병징을 관찰 기재하고 접목전염시험을 하였다. 본병은 전형적인 mosaic의 양상을 이루며, 접목에 의하여 용역하게 전염되는 것으로 미루어 일종의 virus병으로 생각된다. 접목전염시험에 있어서는 건묘에 병수를, 또는 병근에 건수를 접함으로써, 공히 용역하게 전염시킬 수 있었다. 건묘에 병수를 접한 것에서는, 접하고 일정기간 경과 후 (10-30일) 접수(병)를 박리한 것이, 박리않고 그대로 방치한 것에 비하여 훨씬 감염발병이 양호하였으며, 대목과 접수가 접착한 10-30일간에 있어서의 접착기간의 장단에 따르는 감염율의 증감은 인정할 수 없었다. 그리고 대목과 접수(병)의 유착이 안되었을 경우에도 전염이 되었다. 목병은 그 병징, 접목에 의한 전염, 그리고 즙액전염의 가능(미발표) 등으로 미루어 Atanasoff(1935), 그리고 Milinko등(1961)이 보고한 동남유럽에 분포하는 아까시나무 mosaic disease와 근연의 것이 아닌가 생각된다. 한편 김명오 등(1961)은 한국에 아까시나무 witches broom이 발생하는 것으로 기록했는데, 이는 본 모자이크병을 가리킴이 아닌가 생각된다.