대추나무 미친병에 관한 연구 (1) - 이병식물의 (罹炳植物) 내외형태학적 특징 및 그 명명에 대해서 - = A Study of Virus Disease on Chinese Data Tree (1) - On the external and the internal morphological chracteristics of desease infected plants

다국어 초록 (Multilingual Abstract)

HONG, Soon-Woo, & KIM, Chong-Chin: A study of virus disease on chinese date tree (I). On the external and the internal morphogical characteristics of disease inrected plants. Kor. Jour. Bot. 3 (1). 32-38. 1960 Since the peeuliar virus disease of chinese date tree (Zizyphus jujuba Mill. var. inermis Rehd.) has been noted in South Korea around 1950, 70% to 80% of the economically important trees have been either completely destroyed or infected with the virus, severe damage has been noted, particularly, across the area ranged from middle east to the middle part of Korea, including Seoul area. Yoon,-Koock-Byung in 1958 first reported the disease and described it might be caused by a kind of yellows. But he did not conform in his paper that the disease is pecisely caused by yellows virus. The authors, hereby intend to identify the true cause of the disease of the chinese date tree by studying the external symptoms of the disease and the internal morphological characteristics of the diseaset plant which shows various abnormalities in contrast to the healthy checks. In view of fact that the leaves of the infected plants become yellowish in color similar to the peach yellows, aster yellows, it is likely to be identifiable as the common yellows. Furthermore, the abnormal characteristics observed by the authors are as follow: The floral organs such as petals, sepald, stamens, and pistil turn into vegetative leaves, the leaves on heavily infected plant appear as small sized one and also showing as a common witch`s broom like symptom. There are also an occuring of numerous advantitious shoots developed from both of stems and roots. The amount of photosynthetc starch grains increses iIn parenchymatous cells, necrosis takes place in mesophyll, Partlcularly, Palisade Parenchyma in the leaves of infected plants are distinguished in contrast to the healthy checks. From the symptoms and the present experiments described above, the authors are belived that the disease of chinese date tree is not caused by the yellows. It appears the disease is rather similar to the symptoms of sandal spike virus which was noted in India early in this centry. But the host plant of sandal disease, Santalum album L. and the insect vector, Jassus indicus Wal., have never been reported in Korean flora and the founa. The temperature and the other environmental factors is auite different Korea ard India. Thus the authors believe that the peculiar disease must be an endemic new virus origin in Korea and must be called as shoot cluster disease of chinese date tree.