青檀叶片内生和附生真菌组成及生态分布

Composition and ecological distribution of endophytic and epiphytic fungi from the foliage of Pteroceltis tatarinowii

对我国古老特有植物青檀叶片进行内生和附生真菌的研究,以了解青檀叶片内生和附生真菌的组成特点和探讨内生和附生真菌菌群之间的可能联系,为研究真菌资源多样性、植物附生和内生真菌的相互演化关系及真菌与宿主植物协同进化等提供有益参考资料。研究结果表明,从健康的青檀叶片获得可培养内生真菌839株,附生真菌1857株,共计2696株,鉴定其分属于4目,5科,43属。在目的分类水平上,内生和附生真菌均以丛梗孢目Moniliales为优势菌群,分别占90.23%和92.51%;在科的水平上,内生真菌以暗梗孢科Dematiaceae和丛梗孢科Moniliaceae为优势菌群,分别占47.56%和42.67%,附生真菌以丛梗孢科Moniliaceae和暗梗孢科Dematiaceae为优势菌群,分别占67.04%和25.47%;在属的水平上,内生真菌以黑团孢属Periconia和青霉属Penicillium为优势菌群,分别占31.47%和10.73%,附生真菌以小球霉属Glomerularia、膝葡孢属Gonatobotrys和青霉属Penicillium为优势菌群,分别占20.03%、13.95%和12.22%。青檀叶片内生真菌和附生真菌均存在的菌群数量达到23个属,占53.49%。内生真菌特有的属有6个,共分离19株,占0.70%,附生真菌特有的属有14个,共分离120株,占4.45%。内生真菌的Shannon-Wiener index(H')多样性指数(2.44)和Margalef index(R)丰富度指数(2.88)分别小于附生真菌ShannonWiener index(H')多样性指数(2.57)和Margalef index(R)丰富度指数(3.32),但两者的Evenness index(E)均匀度指数几乎相等。青檀叶片内生和附生真菌菌群组成具有较高的相似性,相似性系数达0.70。通过Fisher's exact test分析表明青檀叶片内生和附生真菌菌群组成无明显差异(P=0.072)。

The endophytic and epiphytic fungi from the leaves of Pteroceltis tatarinowii were studied to understand the composition and evolutionary relationship of endophytic and epiphytic fungal communities on this ancient and peculiar plant.This study provides valuable information about fungal resource conservation and an improved understanding of mutual evolutionary relationships between endophytic and epiphytic fungi and their host plants. Additionally,a rich and sizeable collection of endophytic and epiphytic fungi from this specific plant may provide a unique source of bioactive compounds associated with P. tatarinowii. Healthy plant samples were collected from natural distribution areas of P. tatarinowii in Langyashan Natural Reserve,Anhui Province. A total of 2696 isolates of endophytic fungi（ 839 strains） and epiphytic fungi（ 1875 strains） were identified and classified into 43 genera,5 families,and 4 orders. Both species richness and fungal isolation frequency were significantly higher for epiphytic fungi than for endophytic fungi. The dominant order of endophytic（ 90. 23%） and epiphytic fungi（ 92. 51%） was Moniliales. Dematiaceae and Moniliaceae were the dominant families of both endophytic fungi,representing 47. 56% and 42. 67% of isolates,respectively,and epiphytic fungi,representing 67. 04% and 25. 47% of isolates,respectively. The dominant genera of endophytic fungi were Periconia（ 31. 47%） and Penicillium（ 10. 73%）. Glomerularia（ 20. 03%）,Gonatobotrys（ 13. 95%）,and Penicillium（ 12.22%） were the dominant genera of epiphytic fungi. Twenty- three common genera of endophytic and epiphytic fungi were isolated from leaves of P. tatarinowii, accounting for 53. 49% of isolates： Penicillium, Aspergillus, Geotrichum,Gonatobotrys,Streptomyces, Glomerularia, Paecilomyces, Oidiodendron, Trichoderma, Alternaria, Torula, Periconia,Clasterosporium,Phragmocephala,Endophragmia,Stigmella,Acaulopage,Spiromyces,Syncephalastrum,Choanephora,Phomopsis,Gloeosporium,and Marssonina. Six genera（ 19 strains,0. 70%; Oedocephalum,Gilmaniella,Pithomyces,Trichaegum,Colletotrichum,and Sphaceloma） were unique to endophytic fungi,and 14 genera（ 120 strains,4. 45%;Candida,Botrytis,Tritirachium,Trichothecium,Thallospora,Basidiobotrys,Chaetopsis,Bipolaris,Menispora,Cordana,Polythrincium,Cochlonema,Mycotypha,and Stylopage） were unique to epiphytic fungi. Differences in the composition of endophytic and epiphytic fungi existed at different sampling locations. Periconia（ 20. 5%）,Penicillium（ 5. 24%）,Trichoderma（ 8. 70%）,and Streptomyces（ 5. 13%） were the dominant genera of endophytic fungi from the sunward-facing sample leaves,whereas,the dominant genera of epiphytic fungi were Glomerularia（ 20. 03%）,Penicillium（ 11. 74%）,Periconia（ 6. 84%）,and Gonatobotrys（ 5. 65%）. The dominant genera of endophytic fungi from the shade sample leaves included Periconia（ 11. 08%）,Penicillium（ 5. 48%）,and Oidiodendron（ 6. 20%）,whereas the dominant genus of epiphytic fungi was Gonatobotrys（ 6. 57%）. Periconia was the dominant genus of endophytic fungi isolated from the upper（ 17. 76%） and lower（ 13. 59%） leaves. Penicillium was the dominant genus of epiphytic fungi isolated from the upper（ 8. 94%） and lower（ 5. 01%） leaves. The Shannon-Wiener diversity index（ H＇ = 2. 44） and Margalef richness index（ R= 2. 88） of endophytic fungi were less than that of epiphytic fungi（ H＇ = 2. 57,R = 3. 32）. The endophytic and epiphytic fungal communities of P. tatarinowii had a similarity coefficient of 0. 70. Fisher＇ s exact test analysis suggested that there was no significant difference（ P = 0. 072） between the composition of endophytic and epiphytic fungi from the foliage of P. tatarinowii.