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研究了小核盘菌保藏过程中活力和致病力影响因素,结果表明:接种后培养6 d的小核盘菌活力(以该菌在PDA平板上培养形成的菌落直径表示)和致病力(以该菌在蒲公英叶片上形成的菌斑直径表示)最大,分别为66.2 mm和52.9 mm。保藏期间小核盘菌的活力和致病力均随时间呈下降趋势。保藏90 d后,培养8 d的小核盘菌的活力和致病力最大,分别为31.7 mm和17.9 mm;培养4 d的小核盘菌的活力和致病力最小,分别为6.3 mm和2.6 mm。保藏期间低水活度有利于小核盘菌活力和致病力的保持,活力和致病力均随水活度的降低而增加。当水活度低于0.432时,活力和致病力不再增加,趋于稳定。低温有利于小核盘菌活力和致病力的保持,25℃下保藏90 d的小核盘菌失去了全部活力和致病力,而-16℃下小核盘菌的活力和致病力仅分别下降25.8%和13.7%。
The factors affecting the viability and pathogenicity of S. sclerotiorum during storage were studied. The results showed that the viability of S. sclerotiorum, cultured for 6 days after inoculation (indicated by the diameter of colonies formed on PDA plates) (Expressed in terms of the bacterial plaque diameter formed on dandelion leaves) of 66.2 mm and 52.9 mm, respectively. The viability and virulence of S. sclerotiorum declined with time. After 90 days of storage, the viability and virulence of S. sclerotiorum cultured for 8 d reached the maximum of 31.7 mm and 17.9 mm, respectively. The viability and virulence of S. sclerotiorum cultured for 4 d were the smallest at 6.3 mm and 2.6 mm. The low water activity during storage is in favor of the maintenance of viability and virulence of S. sclerotiorum, with the increase of vitality and pathogenicity with the decrease of water activity. When the water activity is lower than 0.432, vitality and virulence no longer increase, tend to be stable. Low temperature is conducive to the maintenance of the viability and pathogenicity of S. sclerotiorum, and all the activity and virulence of P. sclerotiorum stored at 25 ℃ for 90 d lost its viability and virulence at -16 ℃ Only decreased by 25.8% and 13.7% respectively.