Microscopic distribution and quantitative detection of endophytic fungus Undifilum oxytropis from Oxytropis glabra DC and Astragalus variabilis

Abstract:

Abstract: ［Objective］ The characteristics of microscopic distribution and content of Undifilum oxytropis were observed and quantified in different tissues of Oxytropis glabra and Astragalus variabilis from natural grasslands of Inner Mongolia and Ningxia Province.［Methods］ Distribution of fungal endophyte was obtained in all the tissues (stems，leaves，seeds and roots) of O. glabra and A. variabilis though paraffin section and staining method of lactic acid phenol cotton blue;and content of fungal endophyte was determined though Ｒeal time-qPCR．［Results］ Endophytc fungi were observed mainly within the gap between the palisade tissue and parenchymatous tissue of seed coat in seed，mainly colonized in the superficial cells layer near stoma in the leaves，and in pith of stem mainly plants in the parenchymatous tissue around the edge of the vertical axis of the vascular bundle. There was an obviously difference in concentration of U. oxytropis in the plants collected in different locations．The content of U. oxytropis was highest in all seeds of O. glabra，while it was opposite in stems and leaves of two sampling points. Similarly，the content of U. oxytropis was highest in seeds，it was lowest in roots，and stems and leaves were opposite in A． variabilis from two sampling points. The detection limit was 0.029 pg/ng total DNA by Real time-qPCR.［Conclusion］When endophytic fungi infected the tissues of plants，there was selectivity to the tissues and cell type of host，and the colonization and distribution were influenced by habitats in fungal endophytes of locoweeds．

Key words:Keywords: Oxytropis glabra DC，Astragalus variabilis，locoweed，endophytic fungi，microscopic distribution，real-time qPCR