Estimation Of The Number Of Mating Type Factors Of Wild Pleurotus Eryngii Var.Tuoliensis In China

The number of mating type factors is the foundation of germplasm resources diversity. The larger number of incompatible factors, the higher compatible rate of mating between monokaryons from different sources, the more abundant material for cross breeding and the higher possibility of access to superior strains. Pleurotus eryngii var. tuoliensis is rare edible and medicinal fungi in our country and breeding of superior strains has been an important aspect. However, what has been setting breeders in trouble is that the genetic research on P. eryngii var. tuoliensis is relatively rare. In order to investigate the genetic diversity and the genetic abundance of natural populations of Pleurotus eryngii var. tuoliensis in China, the number of mating type factors of P. eryngii var. tuoliensis was estimated in this study.Antagonistic test and CO1molecular test were used to confirm that the142wild strains which collected from Qinghe, Yumin and Tuoli counties about11different collection points in Xinjing province were distinctive Pleurotus eryngii var. tuoliensis and remove the repeated strains and P.eryngii var.ferulae. Then52strains was tested. Monokaryons were preparated by protoplasting of the dikaryotic mycelia. The number of A and B factors was determined by conventional mating type analysis methods and OWE-SOJ technique. Chi-square test was used to analyze the distribution of both A and B specific factors. The total number of A and B factors in natural population was estimated by Raper formula. The results show that:1Mating-compatible monokaryons were successfully derived from33strains, monokaryons of only one mating type relative to the parental dikaryons were isolated from another18strains and strain03263was repeated several times, without monokaryon.84monokaryons were prepared in this research. There were54specific A factors and59specific B factors, accounted for64.2percent and70.2percent of the total number of monokaryons respectively in the sample which had84monokaryons. Appeared only one time of specific A factors and B factors accounted for61.1percent and71.2percent of the total number of specific factors respectively. Two times of the specific A and B factors accounted for29.6percent and18.6percent. The proportion appear three times and more than three times were low, accounting for9.3percent and10.1percent.2Among specific mating type factors A, two factors repeated three times and these factors existed in the six tested materials; two factors repeated four times and the two existed in eight materials; one factor repeated five times and existed in five of the tested materials. The materials had the same factor A located in different collection areas, except the materials had the same factor A repeated four times on the natural distribution overlap. Among specific mating type factors B, four factors repeated three times and those twelve materials from ten different collection areas; two factors repeated four times and those eight materials from seven different collection areas. It indicated that the incompatibility factors were random distribution and repeated or not has nothing to do with the geographical area.3The frequency of the indentical factors appeared were low, and the range is0.57-1.51%, median is1.37%both in sub-samples and between sub-samples. Frequency of the indentical A factors appeared were as same as the indentical B factors appeared in the sub-sample I and higher than the indentical B factors appeared in the rest sub-samples and between sub-samples. The chi-square value of the indentical factors appeared both A and B were less than the theoretical value which show that the indentical A and the indentical B were appeared equal probability and mating type factors A and B were random distribution in the sample of this study.4There would be79different A factors and100distinct B factors in natural population of P. eryngii var. tuoliensis in Xinjiang, China, by the Raper formula and the putative mating type factors from monokaryon are7900, and for dikaryon, there would be31201050in nature. In conclusion, there are rich genetic diversity of P. eryngii var. tuoliensis in Xinjiang, and Xinjiang is a valuable wild P. eryngii var. tuoliensis germplasm resource pool.