| Elymus dahuricus is a high yield and good quality forage grass growing in northern China rangeland, it plays an important role in environmental protection and forage production. Five wild populations of El. dahuricus infected with grass endophyte were used in this study, of which, four populations were planted in Lanzhou in 2004, they are Wulingshan (WLS), Qinyuan (QY), Wutaishan (WTS) and Baiwangshan (BWS), and another wild population was collected in Yili of Xinjiang Uygur Autonomous Regions in 2009. The endophytic fungi were isolated from all 5 wild populations of El. dahuricus and taxonomic study was carried out by morphology and phylogenetic analysis inferred from tub2 and tefl intron sequences. Contents of ergine and ergonovine in leaf blades, pseudostems, leaf sheaths, roots and seeds of the 4 populations of El. dahuricus growing in Lanzhou were detected with high performance liquid chromatography (HPLC). The main results were as follows:1.The morphological measurements showed that the endophytic fungi isolated from 5 wild populations of El. Dahuricus were within the range of morphologic characters of Neotyphodium endophytes according to the colony growth, length of conidiogenous cell, and the size of the conidia, and they belong to the same species. But it was distinguished from the other 22 Neotyphodium species reported in the literature. Phylogenetic relationships based on sequences of tub2 introns and tefl introns revealed that the fungi clustered together in a distinct subclade, which is different from other 22 Neotyphodium speices. Therefore, the fungus isolated from El. Dahuricus could be a new Neotyphodium species.2. The ergot alkaloids were detected in the 4 El. dahuricus populations infected with Neotyphodium endophyte. The contents and distribution of ergine and ergonovine were varied with the grass populations. The contents of ergine were significantly higher than those of ergonovine (P<0.05). A positive linear correlation was existed between the contents of ergine and ergonovine (P<0.01) with r=0.827.3. Ergine and ergonovine were detected in leaf blades, pseudostems, leaf sheaths, roots and seeds of El. dahuricus infected with Neotyphodium of the 4 populations tested. The findings of alkaloids in the root systems have been rarely reported previously in the world literature, although the levels of ergine and ergonovine detected in the roots were low, which were only 0.552～9.970 mg/kg and 0.128～3.207 mg/kg, respectively. The contents of ergine and ergonovine found in roots in August were lower than those found in other months, which were only 0.552～0.576 mg/kg and 0.128～0.283 mg/kg, respectively.4. The highest concentration of ergine were found in leaf blades and leaf sheaths in April, June and August, the concentrations ranged 5.037～30.037 mg/kg for leaf blades and 6.259～22.255 mg/kg for leaf sheaths; its concentrations reached 5.045～8.971 mg/kg in the seeds and 3.119～6.658 mg/kg in the leaf blades in October, which were higher than those in other parts of the plants. The concentrations of ergine in various parts of the plants were significantly higher in April and June (13.831～30.037 mg/kg) than those in August and October (3.119～6.658 mg/kg) (P<0.05).5. The contents of ergonovine in various parts of the plants were similar with ergine. The highest contents of ergonovine were detected in leaf blades and leaf sheaths in April, June and August, which ranged 2.206～8.226 mg/kg for leaf blades and 0.268～5.490 mg/kg for leaf sheaths; the highest contents of ergonovine were found in seeds and leaf blades in October, and reached 1.647～5.664 mg/kg in the seeds, and 1.353～2.251 mg/kg in the leaf blades The concentrations of ergonovine detected in leaf blades, pseudostems and leaf sheaths in April and June (5.102～8.226 mg/kg) were significantly higher than that in August and October (1.353-2.251 mg/kg) (P<0.05). |
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