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

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.

[Distribution of endophytic fungi in Oxytropis glabra DC].

OBJECTIVE: Endophytic fungi were detected and isolated from the stems, leaves, petioles and seeds of Oxytropis glabra DC sampled from Alashan of Inner Mongolia to investigate the infection rate and species distribution in different tissues. METHODS: The endophytic fungi infection rate and distribution of species in different tissues were investigated by making temporary slides, staining, isolation and identification. RESULTS: Endophytic fungi were detected and observed from all parts (stems, leaves, petioles and seeds) of the plant by temporary slides staining. A total of 79 isolates were cultivated from 4 different tissues by common separation methods, which belonged to 10 genera after identification. The infection rate and separation rate were seeds > leaves > stems > petioles. Undifilum oxytropis, Embellisia sp. L12 and Fusarium equiseti were the dominant species in this plant with the relative isolate frequency 77.32%, 64.00% and 50.00%, respectively. CONCLUSION: Endophytic fungi were commonly found in the all parts of Oxytropis glabra DC. There was an obviously difference in quantity, species and distribution of the endophytic fungi between different parts of plant. Seeds and leaves were the most vulnerable to infection and colonization by the endophytic fungi.