Study On The Diversity Of Wild Germplasm Resources Of Auricularia Heimuer

Auricularia heimuer,with its unique nutritional value and ecological value,has anti-aging,anti-hepatitis,anti-ulcer,hypolipidemic and other health care effects.Auricularia heimuer is China’s second largest edible fungus,accounting for more than 99% of the world’s total production,its cultivation area increased more than 15% per year,and there is a high demand for noble varieties in the current production,germplasm is the genetic material that can be passed on to the offspring by parental generation,germplasm resources are the basis of breeding excellent varieties,the breeding of good varieties of edible fungi requires a large amount of wild germplasm resources,the wild germplasm resources of Auricularia heimuer are very abundant in China,this provides a basis for screening elite germplasm from wild Auricularia heimuer.Under the special funding of the National Modern Agricultural Industrial Technology System(CARS-20)and the National Natural Science Foundation of China(31272219),this paper systematically studied the physiological characteristics,esterase isoenzymes,agronomic traits and the diversity of SSR molecular markers of 63 strains of wild Auricularia heimuer collected from across the country,aim of this study was to provide the exact source of germplasm resources for genetic breeding of Auricularia heimuer,supporting the sustainable development of the Auricularia heimuer industry and provides the basis for further development of Auricularia heimuer genetic breeding.The results are as follows:(1)Strains on physiological characteristics of the study showed that the tested strains were rich in diversity,by checking the somatic incompatibility of the tested strains in all combinations,revealed that 99.95% of the somatic incompatibility combinations have somatic incompatibility.So the results indicated that physiological characteristics of the strains were different.Only the strains A245 and A246 exposed somatic cell affinity that is 0.05%,and there is no physiological characteristics difference between them.(2)The study of esterase isozyme in the tested strains revealed that there was abundant diversity in the isozymes,a total of 468 bands were detected,and each strain had 4-13 different enzyme bands.There are 48 enzyme bands with different mobility,and the mobility ranges of bands between 0.048 and 0.855.The highest frequency is 100% when the mobility of band is 0.449,the second frequency is 97.01% when the mobility of band is 0.485,so they can be used as characteristic bands among tested strains.When the mobility of bands is 0.855,0.048,0.659,0.122,0.708,0.774,then the frequency is low as 4.48%,7.46%,7.46%,10.45%,10.45% and 10.45%.They can be used as specific bands for the corresponding strains among the tested strains.NTSYS-PC cluster analysis showed that there was abundant genetic diversity among the strains,and the strains could be divided into four major groups at a coefficient of 0.6612.Group I and II are all southern strains,group III and IV are mainly northern strains,there are certain regional differences among the tested strains.(3)The study on agronomic traits of the tested strains revealed that the strains was rich in diversity.The growth rate of mycelium was 1.839-11.303mm/ day.The strain with the fastest growth rate of mycelium was A345 and the strain with the slowest growth rate was A271.The growth period is 72-146 days.According to the rule of Auricularia heimuer DUS,early maturing strain,medium mature strain,late mature strains calculated for approximately 4.77%,12.70% and 82.53%,respectively.On the basis of mycelium they are divided into three types i.e.the mycelial thick type strains consists of 55.56%,the relatively dense mycelium strains consists of 41.27%,and the sparse mycelia strains consists of 3.17%.There were approximately 76.20% and 23.80% of pigment-secreting strains and non-pigment-secreting strains,respectively.Chrysanthemum-type strains and cluster-type strains accounted for approximately 88.89% and 11.11%,respectively.Ear patch texture medium strain,ear hard texture strains,ear soft texture strains accounted for approximately 73.02%,17.46%,and 9.52%,respectively.The dry ear weight of every 100 kg dry material is 2.04-8.04 kg.High-yield strains,middle-type strains,and low-yield strains calculated for approximately 9.52%,31.75%,and 58.73%,respectively.The dry-to-wet ratio of the ears is 6.85-7.73.It was found that the mycelium growth rate was not positively correlated with the growth period.The strain A184 was proved to have outstanding performance in growth period,commercial traits,and yield.It can be used as a specific germplasm and has the potential to develop into a new variety.(4)The SSR molecular markers of the experimental strains were exposed to be rich in diversity,the amplification bands of all strains are 100-180 bp,same primers have different specific bands for various strains,moreover,the specific bands amplified by different primers corresponding to the same strain are also different.The NTSYS-PC cluster analysis showed that there was abundant genetic diversity among the strains,the 63 strains could be divided into seven major groups at a coefficient of 0.6816.Group I and V are all southern strains,group VII is all northern strains,group II,III and VI are dominated by northern strains,there is no obvious difference between the north and the south strains of the group IV,there are certain regional differences among the tested strains.