Taxonomy And Diversity Of Endophytic Fungi In Wild Soybean In The Yellow River Delta

Glycine soja is a species of annual twining herbaceous plants and a national second-level protected plant in China.At present,there is a lack of research on the diversity of endophytic fungi in G.soja.Endophytic fungi are fungi that live in various tissues and organs of healthy plants at certain or all stages of their life cycle and do not cause obvious symptoms of plant diseases.In order to understand the diversity of endophytic fungi in G.soja,and provide a basis for studying the interaction between G.soja and endophytic fungi,we isolated endophytic fungi of the stems and leaves of G.soja from the peripheral area of the Yellow River Delta Nature Reserve in Dongying,Shandong by tissue separation method.Endophytic fungi were identified based on morphological characteristics and r DNA-ITS sequence alignment,and the composition and diversity distribution were analyzed.404 endophytic fungi strains were isolated from 750 tissues of G.soja,of which Ascomycetes accounted for 87.14% and Basidiomycetes 8.17%.The Ascomycetes contains 3 classes,8 orders,12 families and 18 genera,of which Dothideomycetes accounted for 79.21%,Sordariomycetes 7.43% and Leotiomycetes 0.5%.In the endophytic fungi of G.soja,there are 12 genera in leaves,13 genera in stems and 7genera in stems and leaves.The diversity index of Shannon-Wiener is 1.287,and that of Fisher's alpha is 3.86;In the dominant family,the relative abundance of Pleosporacea was 74.26%,and the relative abundance of Alternaria was 70.30%,followed by Diaporthe 3.71%,Bipolaris 3.22%,Botryosphaeria 2.48% and Fusarium Fusarium2.23%.The Shannon-Wiener diversity index of culturable endophytic fungi in leaves and stems of G.soja was 0.887 and 1.319 respectively.There are 9 families and 12 genera of culturable endophytic fungi in leaves and 9 families and 13 genera in stems.The similarity of the composition of culturable endophytic fungi in leaves and stems is0.56.The diversity of endophytic fungi in stems of G.soja was higher than that in leaves.The comparison of the composition of endophytic fungi between leaves and stems showed that the assemblages of endophytic fungi in different tissue parts of G.soja were spatially heterogeneous.Based on morphological characteristics and r DNA ITS molecular sequence,the endophytic Diaporthe species from G.soja was identified as Diaporthe sojae.And the growth-promoting culture of endophytic Diaporthe species from G.soja was studied.Diaporthe sojae was first found in G.soja as an endophytic fungus,it was previously reported to occur in Glycine max,causing stem and pod blight.The characteristics of endophytic Diaporthe sojae in G.soja and Glycine max and 11 kinds of Diaporthe found in Glycine max were compared and discussed.