Study on classification of oriental melons

为了阐明东方甜瓜的转基因过程，对东南亚、中国和日本的甜瓜品种进行了形态、生态和生理差异的研究。与日本和中国的甜瓜相比，东南亚的甜瓜叶片切口较浅。与其他甜瓜相比，它们的叶柄上的刺较小。东南亚甜瓜的种皮细胞层为双层，而中国和日本甜瓜的种皮细胞层为三层，与日本和中国甜瓜相比，东南亚甜瓜在低温条件下的茎伸长较差。我国甜瓜在高温条件下表现出较好的伸长特性。东南亚的甜瓜表现出最强的抗旱性，种子休眠较深。东南亚和中国的一些甜瓜显示出一种在日本没有的糖。东南亚瓜类酸性磷酸酶同工酶谱与日本和中国瓜类不同。根据形态学、生态学和生理学数据进行聚类分析，将东方甜瓜分为“东南亚”型和“中日”型两大类。然而，日本和中国的腌制甜瓜以及日本的野生甜瓜被归类为“东南亚”类型。

In order to clarify diversion process of oriental melon, morphological, ecological and physiological differences among cultivars in South East Asia, China and Japan were investigated. Melons in South East Asia had leaves with shallow incision compared with those in Japan and China. They had smaller pricks on petiols compared with the other melons. Melons in South East Asia showed double cell layers in seed coat, whereas some of Chinese and Japanese melons showed a triple cell layers.Melons in South East Asia showed poor stem elongation under low growing-temperature condition, compared with those in Japan and China. Melons in China showed good stem elongation under high growing-temperature condition. Melons in South East Asia showed the highest drought resistance.Melons in South East Asia showed deep seed dormancy. Some melons in South East Asia and China showed a sugar which was not found in those in Japan. Pattern of acid phosphotase isozymes in melons of South East Asia differed from that in Japanese and Chinese melons. Phenolic compounds in leaf in South East Asia also differed from those in the other melons.Cluster analysis, using morphological, ecological and physiological data, suggests that oriental melons were classified into two groups 'South East Asia' type and 'Chinese and Japanese' type. However, pickling melons in Japan and China and a wild melon in Japan were classified to 'South East Asia ' type.