棉花枯萎病菌的致病性及其碳素营养的试验研究

南通棉花枯萎病菌对22个棉花品种致病性的田間和盆栽試驗说明:中棉品种如辽阳一号、鶯湖棉、长丰黑籽、常紫一号、南通白花鸡脚桠鈴果、云南布沼土棉等抗病性比較強,以中棉为母本的中印杂交棉的抗病性也較強;陆地棉和海島棉一般感病程度都較高,但四川选育的陆地棉品种52—128則具有一定的抗病性。将枯萎病菌接种到甘藷等27种作物上,均未感病。五个地区的棉花枯萎病菌致病性的盆栽試驗说明:四川、陝西、辽宁的病原菌致病力較強,江苏的其次,安徽的最弱。以葡萄糖、果糖、半乳糖、甘露糖、乳糖、蔗糖、菊糖、溶解淀粉、阿拉伯糖醇等九种糖和糖醇为碳素营养料时,除四川的病原菌在以半乳糖为碳素营养料时生长中等外,其他都生长旺盛。不同地区病原菌的色素形成、小型孢子、大型孢子和厚膜孢子的产生,随碳素营养料的不同而有所差異。

THE PATHOGENICITY AND CARBON NUTRITION OF THE COTTON wILT ORGANISM, FUSARIUM OXYSPORUM F.VASINFECTUM

During the period 1956-1958, pathogenicity of the cotton wilt organism, Fusarium oxysporum f. vasinfectum (Ark.) Snyder et Hansen, was investigated in both pot and field experiments. Nantung cotton wilt organism was used as inoculum for artificial inoculation of soil. 22 cotton varieties were tested for the disease resistance. Results indicate that all the varieties of Chinese cotton (Gossypium arboreum L.) are more resistant than the varieties of Upland cotton (G. hirsutum L.) and Sea-Island cotton (G. barbadense L.). Nevertheless, the Szechuan "52-128" variety of Upland cotton proves to be rather resistant. The variety selected from the hybridization between Chinese and Indian cotton also shows relatively high degree of disease resistance. The host ranges of Nantung cotton wilt fungus were also tested in 1956 and 1957, and none of the 27 kinds of plants tested is infected with the disease. To compare the pathogenicity of the cotton wilt organisms from different localities of China, specimens were collected from Kiangsu, Shensi, Szechuan, Liaoning and Anhwei Provinces. The virulence of the organisms from these five provinces were tested on 22 cotton varieties in 1957 and 1958 in pot experiments. Results indicate that the isolates from Szechuan, Shensi and Liaoning Provinces are more virulent than those from Kiangsu and Anhwei Provinces; while Anhwei isolates appear to be even weaker than Kiangsu isolates. In general, the varieties of Chinese cotton are more resistant to different collections of this wilt organism from all these five localities than the varieties of Upland and Sea-Island cotton. The following sugars or sugar alcohols were tested as single carbon source for each of the above stated isolates; glucose, fructose, galactose, mannose, lactose, sucrose, inulin, soluble starch and arabitol. The representative isolate from Szechuan grows only moderately on galactose, while isolates from other four provinces grow luxuriantly on all kinds of sugars and sugar alcohols used. The production of pigment, the formation of macroconidium, microconidium and chlamydospore of the organism differ as the carbon source varies.