桑枝、葡萄枝木屑栽培杏鲍菇的配方研究

为了开发新型栽培原料,降低杏鲍菇生产成本,分别以桑枝木屑、葡萄枝木屑为材料,各设置5个不同的杏鲍菇栽培配方,进行菌丝生长速度、生物学效率、子实体农艺性状的比较分析。结果表明,桑枝木屑、葡萄枝木屑不仅可以替代杨木屑、甘蔗渣用于杏鲍菇的栽培,而且添加适当比例的桑枝木屑、葡萄枝木屑可以促进菌丝的生长和子实体产量的提高。添加桑枝木屑的杏鲍菇最佳栽培配方为,甘蔗渣21%、桑枝木屑21%、麦麸18.4%、豆粕粉8.4%、玉米芯18.4%、棉籽壳4%、玉米粉6.8%、石灰1%、石膏1%,生物学效率较常用配方提高10.1%。添加葡萄枝木屑的杏鲍菇优异配方为,甜菜渣10%、葡萄枝木屑40%、麦麸13.8%、豆粕粉5%、玉米芯18.4%、棉籽壳4%、玉米粉6.8%、石灰1%、石膏1%,生物学效率较常用配方提高21.8%。

Protective roles of trehalose in Pleurotus pulmonarius during heat stress response

High temperature is one of the major abiotic stresses that limit edible mushroom growth and development. The understanding of physiological alterations in response to heat stress and the corresponding mechanisms involved is vital for the breeding of heat-resistant edible mushroom strains. Although trehalose functions as a protectant against abiotic stresses in fungi, the putative role of trehalose in thermotolerance remains to be elucidated. In this study, we found heat stress inhibited the growth of two Pleurotus pulmonarius strains, heat-sensitive and less-sensitive, and the inhibition was more significant for the sensitive strain. Heat stress leads to the increase of lipid peroxidation and intracellular trehalose accumulation, with a higher level in the heat-sensitive strain, and this effect is independent of exogenous trehalose application. In addition, a lower concentration of exogenous trehalose application in sensitive strain than in less-sensitive strain was found to alleviate the inhibition of mycelium growth and further increase the intracellular trehalose concentration by heat stress. Thus, the protective effects of trehalose were more remarkable in the sensitive strain. The activities of intracellular trehalose metabolic enzymes, i.e., trehalose-6-phosphate synthase, trehalose phosphorylase and neutral trehalase, were determined, and our data indicated that the changes of these enzymes activities in the sensitive strain were more beneficial to accumulate trehalose than that in the less-sensitive strain.

Identification of commercial cultivars of Agaricus bisporus in China using genome-wide microsatellite markers

Agaricus bisporus is one of the most widely cultivated mushrooms in the world. Commercial cultivars are usually phenotypically alike and easy to be copied by isolating tissue cultures. This brings great challenges to distinguish different cultivars and to protect new varieties. Thus, techniques for the accurate identification of cultivars are essentially required. In this study, we accurately identified 11 commercial cultivars of A. bisporus released in China by using microsatellite(SSR, simple sequence repeat) markers. SSR markers were developed by mining the genome sequence. A total of 3 134 SSRs were identified, of which 1 490 SSRs were distributed in gene models, and 1 644 in the intergenic regions. A total of 17 polymorphic primer pairs were developed and SSR fingerprints were constructed for all the commercial cultivars. These SSR markers generated a total of 73 alleles, with an average of 4.29 per locus. Specifically, the primer combination of AB_SSR_2341 and AB_SSR_2590 could distinguish all the 11 commercial cultivars. The similarity coefficients of the 11 commercial cultivars were between 0.56 and 0.95 indicating that some of them were close related. Our results provide an efficient technique for the identification of A. bisporus cultivars in China, which can also facilitate the marker-assisted breeding in the future.

Genetic variation and population structure of the mushroom Pleurotus ferulae in China inferred from nuclear DNA analysis

To investigate the genetic diversity of an edible fungus Pleurotus ferulae, a total of 89 wild samples collected from six geographical locations in the Xinjiang Uygur Autonomous Region of China and two geographical locations in Italy, were analyzed using three DNA fragments including the translation elongation factor（EF1α）, the second largest subunit of t he RNA polymerase II（RPB2） and the largest subunit of the RNA polymerase II（RPB1）. The results indicated relatively abundant genetic variability in the wild resources of P. ferulae. The analysis of molecular variance（AMOVA） showed that the vast majority of the genetic variation was found within geographical populations. Both the Chinese populations and the Italian populations of P. ferulae displayed a limited genetic differentiation. The degree of differentiation between the Chinese populations and the Italian populations was obviously higher than that between the populations from the same region, and moreover the genetic differentiation among all the tested populations was correlated to the geographical distance. T he phylogeny analyses confirmed that samples from China and Italy belonged to another genetic group separated from Pleurotus eryngii. They were closely related to each other but were clustered according to their geographical origins, which implied the Chinese populations were highly differentiated from the Italian populations because of distance isolation, and the two populations from different regions might be still in the process of allopatric divergence.