Relationship between Environmental Factors and Diversity of Culturable Yeasts in Rhizosphere Soil of Rice Field on Tibetan Plateau

  Objective  Diversity of culturable yeasts in rhizosphere soil of rice fields at Zayü County, Nyingchi City, Tibet was determined and its correlation with the environmental factors analyzed.

  Method  Yeasts from the soil samples were isolated by dilution with a streaking plate method and identified by sequencing ITS domains of rRNA gene and conventional classification. Software R 3.6.1 was used to examine correlations between the yeast diversity and environmental factors.

  Result  A total of 352 yeast strains of 10 genera and 13 species dominated by Cryptococcus podzolicus were isolated. The numbers extremely significantly correlated with the contents of total nitrogen (TN) and total phosphorus (TP) in the habitat rhizosphere soil. TN extremely significantly correlated to both Shannon-Wiener and Simpson diversity indices and significantly correlated to Pielou evenness index, but TP only significantly correlated to Shannon-Wiener diversity index. At species level, the abundance of Candida pseudolambica, Goffeauzyma gastrica, Papiliotrema aspenensis, and Solicoccozyma terricola significantly correlated to TN, G. gastrica and S. terricola extremely significantly and C. pseudolambica significantly correlated to TP, and P. aspenensis extremely significantly correlated to the water content (WC) in soil.

  Conclusion  Different environmental factors affected differently on the rhizosphere yeast community on rice fields in the region. TN and TP in soil appeared to play a prominent role in that respect.