Cultivars Breeding of Morels(Morchella) in China: Current Status and Prospects

Morels(Morchella spp.) are a well-known group of ascomycetes widely distributed in the northern hemisphere, highly favored for their nutritional and medicinal value. China boasts abundant wild Morchella germplasm resources, with the exploration of its artificial cultivation initiated in the 1950s. With the gradual maturity of field cultivation technology in recent years, the economic and industrial values of Morchella have increased year by year, and the rapid development of its industry has become an important driving force for advancing rural revitalization in China. However, the insufficient supply of elite strains constitutes a critical bottleneck restricting the sustainable development of the industry. Based on statistical data from the National Seed Industry Big Data, China National Knowledge Infrastructure(CNKI), and the National Intellectual Property Administration, this study systematically sorted out the current status, achievements and methods of Morchella cultivar breeding in China, identified the existing problems in the current Morchella seed industry, and further put forward relevant thoughts and suggestions. The results showed that the cultivation of Morchella in China has undergone a century of exploration and large-scale production was achieved after the breakthrough of key cultivation technologies in 2012. The cultivation area reached approximately 29 820 hm² in 2023, forming an industrial pattern dominated by the main cultivated species of Morchella importuna, M. sextelata and M. eximia. In terms of cultivar protection, China has initially constructed a three-dimensional protection system comprising cultivar certification, new plant cultivar rights and strain patents, yet there remain prominent issues such as voluntary certification, limited coverage of Distinctness, Uniformity and Stability test(DUS), and a lengthy authorization period. Up to now, a total of 70 Morchella cultivars have been bred nationwide, among which 51 cultivars have passed certification(identification/examination and approval). A total of 36 patent applications for strains have been filed, with 21 authorized, and research institutions are the main breeding entities. At present, wild resources domestication remains the primary approach for Morchella breeding, and technologies such as hybridization, mutagenesis and protoplast fusion have been gradually integrated into breeding practices, followed by systematic screening and identification procedures. DNA-based molecular marker technology has played an important role in cultivar certification and intellectual property protection, but the provision of specific DNA molecular markers is not mandatory. The current Morchella seed industry still faces prominent challenges, including chaos in cultivar naming and application, an imperfect intellectual property protection system, lagging breeding technologies, weak basic research, and unstable strain quality. Thus, this study proposes that it is imperative to strengthen the protection and utilization of germplasm resources, promote the mandatory application of molecular marker technology in cultivar protection, establish a modern molecular breeding system, deepen researches on the growth and development mechanism of Morchella, and improve the standardized production and quality traceability system of strains, aiming to drive the high-quality and sustainable development of Morchella seed industry in China.

Effect of Selenium Supply on Selenium Enrichment in Cordyceps militaris

In order to investigate the effects of different selenium sources on selenium enrichment within fruiting bodies of Cordyceps militaris, four chemical compounds of exogenous selenium(sodium selenite, nano-selenium, chelated selenium and yeast selenium) with various concentrations were added to culture media at the different growth stages(mycelial stage, color transformation stage, primordial stage and growth stage) of C. militaris. Contents of total selenium and organic selenium of the harvested fruiting bodies were measured by using o-phenylenediamine ultraviolet spectrophotometry for analysis and comparison of the effects induced by supplying exogenous selenium with a concentration gradient treatment on the selenium enrichment at four growth stages of C. militaris. The results showed clearly that all of groups treated with the supply of exogenous selenium significantly increased the content of total selenium and organic selenium in C. militaris fruiting bodies when compared with their controls. When 16 mg/L sodium selenite was added at the color transformation stage, the content of both total selenium and organic selenium of C. militaris fruiting bodies reached the maximal value, showing 115.17 μg/g with an enrichment rate of selenium of 719.79% and 105.20 μg/g with an organic conversion rate of 91.34% respectively, in which the rate of organic conversion was 2.34 times higher than that of the control. The above results should provide an important foundation for the future research and development of new and natural supplements of selenium.

Agaricus macrocarpus F.H.Møller

Analysis of Biological Characteristics of Mycelium and Lignification Process in Ganoderma tsugae

In order to promote the use of macrofungal resources, we collected a fruiting body of Ganoderma from Heilongjiang Province of China that was identified as G. tsugae through our morphological observation and molecular biological analysis. Taking this strain as an experimental sample, firstly, we detected its biological characteristics cultured under the medium on the base of four factors: carbon source, nitrogen source, temperature and pH value. By performing an orthogonal test of four-factor and three-level through choosing those superior levels, our results showed that the optimal conditions for its mycelium growth of G. tsugae were to use starch as the carbon source, peptone as the nitrogen source, 5.0 as the pH value and 25 ℃ as the temperature, respectively. Strength of influences revealed by the above four factors on the mycelium growth of G. tsugae was ranked as follows: pH > carbon source > temperature > nitrogen source. We then used the formula containing 90% hard sawdust, 6% wheat bran, 1.5% soybean powder, 1% lime and 1.5% gypsum for cultivation of mushrooms. It needed 30-40 days for the hyphae to grow fully within the above medium in the dark at 25 ℃. Under the conditions with a temperature of 22-28 ℃, a concentration of carbon dioxide less than 7 × 10⁸ and a relative air humidity of 75%-95%, primordia were generated and developed to form fruit bodies of G. tsugae that could be harvested after 30 days. Determination of lignocellulose was conducted during the whole stage of growth and development of G. tsugae fruiting body to analyze its lignification process. It was found that the contents of lignin, cellulose and hemicellulose all increased early and then decreased late with a peak value appearing at the early time of spore maturity. Lignin accounted for the highest proportion of the lignocellulose, followed by cellulose and hemicellulose within the fruiting body of G. tsugae. The present study thereafter lays a foundation for our further understanding of the mechanisms underlying its lignification process and regulation of fruitbody growth and development in G. tsugae.

An Overview of Research on Macrofungal Diversity in China

Macrofungi, recognized as one of the most species-diverse biological groups on earth, play a vital role in maintaining ecosystem functions and promoting sustainable utilization of natural resources. Researc_h on the_divers_ity o_f macrofun_gi_thus holds a pro_found_sign_ificance of science. Through extensive sorting of the relevant literatures, this paper provides a systematical overview of the history, current status, and core challenges on the diversity research of macrofungi in China that covers a number of aspects including species diversity, community structure, floristic distribution patterns and environmentdriving mechanisms as well as prospective directions for future studies.Time for recognition of macrofungi in China could be traced back to BCE(Before Common Era), however, the systematic scientific research in this field started only since the early 20 th century whereby Mr. HU Xianxu became a pioneer to open modern taxonomic studies of macrofungi. After the establishment of the People's Republic of China, nationwide systematic surveys of macrofungal resources were promoted actively by many research institutions and the Editorial Committee of the Flora Fungorum Sinicorum as well. Currently, over 25 000 species of macrofungi have been documented in China, while scientific estimations suggest that the total number of species may reach up to approximate 180 000 implying an existence of about 86% of the species still without being recorded. Our comprehensive analysis of literatures indicates a significant geographical disparity in the collection and accumulation data of species diversity across China, which were extensively rich from the central, northern and northeastern regions whereas very poor from the large areas of southern and northwestern China as well as the Qingzang Plateau due to inadequate exploration. At the national scope, the dominant families and genera of macrofungi are mainly constituted of temperate components such as Agaricaceae, Polyporaceae, and Russula. Vegetation types have a significant impact on the community structure of macrofungi where a higher diversity is seen from the mixed coniferousbroadleaved forests when compared with the pure forests and the coverage of Quercus mongolica reveals, moreover, a significant positive correlation with the above species diversity(P<0.05). Suitable human interventions, such as thinning, can enhance species richness, while overexploitation may result in a severe degradation of communities. Analysis of floristic compositions reveals that the northtemperate and cosmopolitan species constitute over 70% of the total species, indicating their strong affinity with the temperate floras of East Asia and Europe. The occurrence and geographical distribution of macrofungi are considered to be influenced by various environmental factors including precipitation, temperature, altitude and soil physicochemical properties(pH and organic matter content) as well as host tree specificity.In summary, the research of macrofungal diversity in China is currently facing several critical challenges as represented by the pronounced imbalance of regional coverage, the difficulty of taxonomic identification of species, the lack of enough knowledges against key processes and mechanisms of ecology, and the increasing demands of resource conservation. Consequently, our future endeavors to do scientific study for comprehensively elucidating the patterns, formation mechanisms and conservation strategies of macrofungi should be focused on the following areas:(1) Expanding the scope and frequency of investigations to fill in gaps of research activity particularly for those critical regions such as the northwestern China, the Qingzang Plateau and the nature preserves in southern China as well, and establishing a longterm continuous monitoring network;(2) Enhancing the public awareness through strengthening activities of science communications to help understanding of the value of macrofungi and increasing the research investment by calling for great supports from governmental agencies and research institutions for basic studies;(3) Promoting the technological innovation and interdisciplinary collaboration by actively integrating those advanced means such as modern molecular biology, bioinformatics and ecological modeling essential to resolve current bottlenecks existing in the traditional taxonomic and ecological research areas.

Optimization of Hot Water Extraction Techniques and Evaluation of Antioxidant Activity of Polysaccharides Derived from Auricularia cornea 'Yumuer'

This study employed hot water extraction to isolate polysaccharides from Auricularia cornea 'Yumuer'(ACP), examining the effects of extraction temperature, number of extraction cycles, liquid-to-solid ratio, and extraction duration on ACP yield. Both single-factor experiments and response surface methodology were utilized to optimize the extraction parameters and identify the optimal conditions for ACP recovery. The antioxidant activity of ACP was assessed through free radical scavenging assays. Results indicated that the optimal extraction conditions were an extraction temperature of 100 ℃, extraction time of 251 minutes, three extraction cycles, and a liquid-to-solid ratio of 71:1(mL:g). Under these conditions, the ACP yield reached 10.07%, with a deviation of 0.7% from the predicted value. The half-maximal inhibitory concentration(IC₅₀) values for scavenging DPPH, ABTS, hydroxyl, and superoxide anion radicals were 1.87, 1.13, 2.19, and 0.94 mg/mL, respectively, demonstrating dose-dependent antioxidant activity. These findings suggest that ACP possesses significant antioxidant properties, providing a scientific foundation for its further development, utilization, and potential economic value enhancement.

Sequence and Structural Analysis of Sesquiterpene Synthase Gene Family in Ganoderma tsugae

Ganoderma tsugae is a rare and valuable species of Ganoderma in the northeast China area, because it contains abundant compounds of terpenoids. Terpene synthases are key enzymes that promote the biosynthesis of sesquiterpene and other terpene compounds. Based on our high-quality sequence previously obtained from the whole genome of G. tsugae, this study aims to explore the composition and structure of sesquiterpene synthase gene family in this important species. Through sequence and structural comparison of homologous gene among various species of fungi, it was found that there were 10 sesquiterpene synthase coding genes within the whole genome of G. tsugae, which were mainly distributed in five different sequence contigs consisting of seven gene clusters. These genes were known to encode the germacrene A synthase(Cop1 and Cop2), the α-muurolene synthase(Cop3), the δ-Cadinene synthase(Cop4) and the trichodiene synthase(TRI5), respectively, where Cop1, Cop2, Cop3 and Cop4 all carry the typical Terpene＿syn＿C-2 domain. TRI5 contains the Isoprenoid＿Biosyn＿C1 domain. The total sequence of 10 genes ranged in length from 1 178 bp to 1 478 bp, showing a number of two to five introns. Detection of SNP information revealed that nine of the above genes had a multiple number of non-synonymous substitution sites in their coding region between the different wild strains, providing thereafter new natural genetic resources for the subsequent functional study of these key genes relating to the sesquiterpene biosynthesis in G. tsugae.

Effect of Mycelial Shading on Auricularia heimuer on Mechanical Characteristics and Mechanized Harvesting

To address the challenges of high labor dependency, intense manual effort, and low mechanization in the harvesting process of Auricularia heimuer, this study employed black cultivation bags with varying shading rates(ck: 0 shading; T1: 50% shading; T2: 70% shading; T3: 90% shading) to systematically investigate the effects of mycelial shading on the detachment force, mechanical properties, and mechanized harvesting efficiency of the fungus. The results demonstrated that shading treatments significantly reduced the detachment force required to separate the fruiting bodies(P<0.05), exhibiting a decreasing trend with increasing shading intensity. Frequency distribution analysis indicated that the intervals of detachment force varied notably among different treatments and pulling directions. Meanwhile, shading exerted no significant impact on the overall mechanical properties of the fruiting bodies. Notably, treatments T1 and T2 showed superior cohesiveness and hardness. Under identical shading conditions, the angle of applied pulling force significantly influenced detachment force: for the “one-shaped” opening, the horizontal direction exhibited a higher detachment force(2.48 N), whereas for the circular opening, the upward 45° direction showed a higher detachment force(1.49 N). Shading also resulted in a marked reduction in the size of the stipe base and attachment point, thereby weakening adhesion to the cultivation bag and facilitating harvesting. Validation trials with harvesting machinery indicated that, compared to the ck treatment, shading significantly decreased the number of missed and substandard fruiting bodies. When comparing opening methods, the circular opening exhibited a notably lower detachment force than the one-shaped opening; however, the stipe base and attachment points were significantly smaller in the circular opening, which increased the likelihood of immature fruiting bodies being harvested inadvertently, thereby raising the quantity of substandard products and adversely affecting commercial value. Comprehensive analysis suggests that T2 or T3 shading treatments combined with the one-shaped opening method are more suitable for current mechanized harvesting operations of A. heimuer. If the circular opening method is employed, it is recommended to appropriately reduce the harvester's operating speed to enhance harvesting efficiency and product quality.