Identification of physiologic races of soybean rust in Japan and ecology and taxonomy of the fungus.

(1)在茨城、千叶县、神奈川县、静冈县、冈山县、爱美县、高知县、福冈县、熊本县等9个县的大豆、葛根、葛根、大豆叶片上采集到了冬孢子和冬孢子。(2)从茨城、千叶县、静冈县和熊本县采集的夏孢子单菌株12株，用于生理小种鉴定研究。根据AVRDC(1985)用于台湾大豆锈病小种鉴定的11个不同品种的侵染类型，共鉴定出6个不同的小种。其中一个小种在11个不同品种上表现出与台湾小种相同的侵染类型。在熊本县的栽培大豆和千叶县的P.lobata上也发现了相同的小种。这表明至少有一个大豆锈菌小种在日本广泛分布，同一种群在自然界中可能同时利用大豆和大豆作为寄主植物。(3)大豆、大豆和大豆上的夏孢子和冬孢子的形态观察结果与Ono等人对厚根褐孔菌的描述很好地吻合。(1992年)。因此，本研究中所用的真菌为厚根霉。(4)将大豆、大豆和美洲斑潜蝇的幼叶接种于大豆叶片上形成的冬孢子所产生的担孢子上。然而，没有感染的迹象。在生长箱中诱导大豆冬孢子形成的尝试没有成功。

(1) Urediniospores and teliospores were collected on leaves of soybean (Glycine max), Pueraria lobata, and G.soja in the following 9 prefectures ; Ibaraki, Chiba, Kanagawa, Shizuoka, Okayama, Ehime, Kochi, Fukuoka, and Kumamoto. They were deposited as dry herbarium specimens in our institute and also fresh urediniospores were stored in a deep freezer (-80 C).(2) Totally 12 single sorus isolates of the fungus were made from urediniospore cultures collected in Ibaraki, Chiba, Shizuoka, and Kumamoto prefectures and were used for studies on identification of physiologic races. Based on infection types on 11 differential varieties of soybean rust used by AVRDC (1985) for race identification of soybean rust in Taiwan, 6 different races were identified among them. One of the races showed the same pattern of the infection types on the 11 differential varieties as one of the Taiwan races. The same race was found on cultivated soybean in Kumamoto Prefecture and on P.lobata in Chiba Prefecture. It suggests that at least one of the races of soybean rust distributes in wide area in Japan and the same population of the fungus may be able to use both soybean and P.lobata as host plants in nature.(3) Results of the morphological observation of urediniospores and teliospores on soybean, P.lobata, and G.soja, fitted well with description of Phakopsora pachyrhizi by Ono et al. (1992). Thus, the fungus used in the present study was identified as P.pachyrhizi.(4) Young leaves of soybean, G.soja and Meliosma myriantha were inoculated with basidiospores produced from overwnitered teliospores of the fungus formed on leaves of P.lobata. However, there was no sign of infection.Attempts of inducing teliospore formation on soybean grown in a growth cabinet were unsuccessful.