摘要
The xingkai Lake pine(Pinus lakahasii Nakai) gall rust caused by Cronartiumquereuum(Berk.)Miyabe:Shirai is a serious stem rust in the northeast region of China.The alternatehost is oak (Quercus mongolica Fisch).Germination of both acciospores and urediospores wasoptimal at 12℃ and occurred over a range of temperatures,from 4℃ to 32℃.Teliosperes germinatedoptimally at 16--18℃ and over a range of 8--28℃.All spores germinated best under natural light anddark conditions.Direct light inhibited germination eren when followed by darkness.The incubauonperiods of urediospores and teliospores in inoculation experiments were 6--16 days and 3--33daysrespectively. Anatomical studies of Cribartium quercuum galls showed that rust hyphae freely ramify throughthe intereellular spaces within parenchymatous lissues of the cortex,phloem,cambium,and xylemHyphac are perennial;largc haustoria are cylindrical with rounded or blunt ends. Among the 12 fungieides tested for control the rust,pine-tar,pine-tar;diesel oil(1:1。
The Xingkai Lake pine (Pinus takahasii Nakai) gall rust caused byCronartium quercuum(Berk.) Miyabc: Shirai is a serious stem rust in the northeast region of China. The alternate host is oak (Quercus mongolica Fisch). Germination of both acciospores and urediospores was optimal at 12°C and occurred over a range of temperatures, from 4°C to 32°C. Teliospores germinated optimally at 16–18°C and over a range of 8–28°C. All spores germinated best under natural light and dark conditions. Direct light inhibited germination even when followed by darkness. The incubation periods of urediospores and teliospores in inoculation experiments were 6–16 days and 3–33 days respectively.Anatomical studies ofCronartium quercuum galls showed that rust hyphae freely ramify through the intercellular spaces within parenchymatous tissues of the cortex, phloem, cambium and xylem. Hyphae are perennial; large haustoria arc cylindrical with rounded or blunt ends.Among the 12 fungicides tested for control of the rust, pine-tar, pine-tar: diesel oil (1:1, 1:3, 1:5), 75% Bravo emulsion and 70% Mancozeb emulsion applied to the galls produced satisfactory results.
