Abstract:

In this study a dry-heat treatment was used to make endophyte-free populations of Melica transsilvanica. The elimination effects of the seed containing endophyte were tested by treatment at 70℃ for 5 d,10 d,15 d,20 d,25 d and 30 d, and the seeds not treated were used as control. The result showed that at 70℃ for 25 d was effective in killing the endophyte in the seeds. The endophyte was very sensitive to the dry-heat treatment, the endophyte infection rate was reduced to 50% after 5 d treatment, and the endophyte infection rate was reduced to 0 after 25 d treatment. At the same time, there are no obvious differenrces in the seeds germination rate and plant growing indexes. Intriguingly, 70℃ dry treatment can promoting root number and root length. Therefore, 70℃ for 25 d treatment was an simple, convenient and feasible way to make endophyte-free M. transsilvanica germplasm.

Key words: Melica transsilvanica, Endophyte, Dry-heat treatment, Effectiveness evaluation

摘要：

为了更好地研究内生真菌与德兰臭草（Melica transsilvanica）的互作关系，需获得内生真菌种群已失活的德兰臭草种子。本试验采用70℃干热的方法对德兰臭草带菌种子分别处理5 d，10 d，15 d，20 d，25 d和30 d，以不作处理的种子为对照，通过测定各处理后种子的萌发指标、生长指标和植株内生真菌数量等综合评价内生真菌的灭活效果。结果表明，70℃干热处理能有效杀灭德兰臭草种子中的内生真菌；70℃处理5 d后，与对照相比，宿主染菌率下降为50%；处理25 d时，种子和植株中均未分离出内生真菌。同时，70℃处理25 d时，种子发芽率、发芽势、发芽指数、植株鲜重和胚根、胚芽长度以及植株株高、叶片数、分蘖数、叶宽和茎粗与对照相比均没有显著影响。值得一提的是，70℃干热处理种子可促进植株须根数的增多和根长的增加。综合比较得出，70℃干热处理25 d能使德兰臭草种子中全部内生真菌失活，是一种简单、方便、可行的方法。

关键词: 德兰臭草, 内生真菌, 高温处理, 效果评价