物种分布模型在大型真菌红色名录评估及保护中的应用:以冬虫夏草为例

我国大型真菌资源丰富,由于受气候变化和人类活动等的影响,近年来很多物种受到不同程度的威胁,亟待保护。红色名录评估是物种保护的第一步,为有效保护我国大型真菌多样性, 2016年生态环境部和中国科学院联合启动中国大型真菌红色名录评估项目。合理的评估依赖于完善的物种地理分布、种群数量规模及其动态变化信息。大型真菌评估信息较少,需要引入新的方法解决评估信息不足的问题。冬虫夏草(Ophiocordycepssinensis)是一种重要的食药用菌,具有较高的经济价值,受到全世界的广泛关注,评估信息相对充足,此次被评为易危物种。利用物种分布模型对冬虫夏草未来分布区变化的预测在评估过程中发挥了重要作用。为了将物种分布模型分析方法引入大型真菌的受威胁等级评估,本文以此前我们利用物种分布模型预测冬虫夏草的潜在分布区及其对气候变化响应的研究为例,介绍了应用物种分布模型预测大型真菌的潜在分布区、未来气候变化情景下分布区变化趋势的方法和流程,以及在应用中可能存在的问题和解决方案。通过本文的分析,我们认为物种分布模型在大型真菌的红色名录评估和保护中具有重要的应用潜力,值得推广应用。

Dissipation of pencycuron in rice plant

Pencycuron is a non-systemic protective fungicide for controlling sheath blight of rice. However, information on the fate of pencycuron in rice plant is lacking. The degradation of pencycuron in waterlogged tropic rice field was investigated.Pencycuron was applied at recommended field dose (187.5 g a.i./ha) and double recommended dose to cropped plots for three consecutive years. Pencycuron was rapidly degraded in rice plant at all doses of pencycuron application with first order half-lives of 1.57～2.77 d. The study revealed that pencycuron is safe from the human and environmental contamination point of view.

Applications of Trichoderma formulations in crop protection

The choice of active Trichoderma strains is important in designing effective and safe biocontrol applications. Many species of Trichoderma have multiple strategies for fungal antagonism and indirect effects on plant health, such as growth promotion, systemic resistance induction and fertility improvements. Some strains are powerful antibiotic producers, and their suitability for use in biocontrol systems must be carefully assessed. However, many other active strains have no antibiotic capacity, and these are likely to be more useful in food production systems since they have not adverse effects on important groups of beneficial soil organisms. We have assessed the performance of selected naturally occurring Trichoderma strains (singly and in combination) and developed TUSAL, a mixture of Trichoderma harzianum and T. viride that has demonstrated to be effective against major pathogens in sugar beet and horticulture. TUSAL, has been bulked up and tested under field conditions, showing positive effects on precocity and root development, and increasing the crop production in field trials carried out in different pathosystems. The environmental impact of TUSAL strains on beneficial organisms in the environment were assessed before release, and molecular detection methods were developed to monitor the presence and performance of strains in the field. In addition, Trichoderma protein extracts with high glucanase and chitinase activities, have also been obtained from wild type strains and their effectiveness as biofungicides was tested in laboratory and field conditions, defining the concentration of protein necessary to produce fungicide effects. The genes coding for protein production were introduced into suitable organisms for large-scale production in the laboratory, never released to the environment. The effect of these novel biofungicide proteins was studied separately and synergistically with Trichoderma conidia, and with minimal doses of chemical fungicides. Suitable active Trichoderma strains are being registered in the EU by the company NBT. Both Trichoderma strains and proteins are included in formulations patented as biocontrol agents.

中国大型真菌红色名录评估中存在的问题及今后的对策

2018年5月22日国际生物多样性日,生态环境部和中国科学院联合发布了"中国生物多样性红色名录--大型真菌卷",对9,302种大型真菌的受威胁现状进行了评估。根据大型真菌的生物学特性,此次评估还对IUCN红色名录评估等级标准体系进行了适当调整。本文总结了评估过程中发现的问题:(1)部分物种的分类学地位存在争议,缺少汉语学名;(2)大量物种的地理分布、种群数量及动态变化等信息缺乏;(3) IUCN的部分评估标准在大型真菌中难以使用;(4)物种的受威胁因素不明确,缺乏科学定量的分析。针对以上问题,我们建议:(1)加强真菌分类学研究,按命名规范拟定物种的汉语学名;(2)加强大型真菌的资源调查,对重要物种和多样性热点区域进行长期定点监测;(3)引入物种分布建模等定量分析方法,完善IUCN的评估标准,使之更适用于大型真菌的评估;(4)鼓励公众参与,建立交流互动平台,扩大红色名录工作的影响,加强大型真菌多样性保护。

Metabarcoding技术在真菌多样性研究中的应用

由于受到气候变化、土地利用变化及环境污染等诸多因素的干扰,真菌多样性受到不容忽视的威胁,亟需得到保护。构建物种数据库是实现真菌多样性研究和保护的重要前提。近年来兴起的DNA条形码及metabarcoding技术能够在很大程度上弥补传统鉴定方法的缺陷,可对真菌物种进行大规模、准确、快速、高效地鉴定。本文梳理了metabarcoding技术在真菌物种多样性评估、真菌多样性影响机制和真菌古生态重建等研究中的应用,同时强调了metabarcoding技术用于真菌多样性研究尚处于初期阶段,在构建有效参照数据库、优化实验流程以及升级生物信息学工具等方面仍需要进一步的完善。建议加强真菌分类学家、生态学家以及计算机工具研发工程师之间的合作,共同解决metabarcoding技术在真菌多样性研究及应用中面临的问题,为宏观尺度上真菌多样性保护提供更加科学的依据。

A Checklist of Macrofungi in Yaoluoping Nature Reserve,Anhui

Field work to survey and investigate the Anhui Yaoluoping Macrofungi Nature Reserve was undertaken in order to understand and rationally develop macrofungi resources. The results showed that there are, in total, 101 macro-fungal species and varieties, including 59 kinds of edible mushroom, 20 kinds of medicinal mushroom, and 8 kinds of toadstools, grouped according to their economic values. The species belong to 5 classes, 13 orders, 43 families and 67 genera, Another 14 species are unknown fungus food or medicine and remains to be further de- veloped. They are widely distributed in broad-leaved forests, mixed forests, coniferous forests, bamboo forests, wastelands and areas with other vegetation types. Large fungi resources are abundant; some varieties are rare and very valuable to develop. Among those of value are some edible and medicinal mushrooms, anti-cancer sulfur bacteria, morchella, gold equivalent cow bacilli, pine mushrooms, etc. Some species and species resources have still not been fully investigated. These large fungi can be domesticated and cultivated, and have very good commercial development prospects.

Potential natural exposure of endangered red-crowned crane(Grus japonensis) to mycotoxins aflatoxin B_1, deoxynivalenol, zearalenone, T-2 toxin, and ochratoxin A

A survey was conducted to determine whether mycotoxins were present in the foods consumed by red-crowned cranes（Grus japonensis） in the Yancheng Biosphere Reserve, China. Collected in the reserve＇s core, buffer, and experimental zones during overwintering periods of 2013 to 2015, a total of 113 food samples were analyzed for aflatoxin B1, deoxynivalenol, zearalenone, T-2 toxin, and ochratoxin A using high performance liquid chromatography（HPLC）. The contamination incidences vary among different zones and the mycotoxins levels of different food samples also presented disparity. Average mycotoxin concentration from rice grain was greater than that from other food types. Among mycotoxin-positive samples, 59.3% were simultaneously contaminated with more than one toxin. This study demonstrated for the first time that red-crowned cranes were exposed to mycotoxins in the Yancheng Biosphere Reserve and suggested that artificial wetlands could not be considered good habitats for the birds in this reserve, especially rice fields.

Effects of cutting frequency and height on alkaloid production in endophyte-infected drunken horse grass (Achnatherum inebrians)

An evaluation was performed on the influence of mowing height (2.5,5.0 or 7.5 cm) and mowing frequency (weekly or fortnightly) on levels of ergot alkaloids (ergine and ergonovine) formed in drunken horse grass,Achnatherum inebrians,grown under greenhouse conditions.Samples were taken monthly and alkaloids were extracted and analyzed by reverse-phase HPLC.Alkaloid levels increased more or less linearly with plant age over the first four months following establishment.Levels were higher in samples cut fortnightly compared to those cut weekly,and were higher when plants were cut at a mowing height of 7.5 cm vs.2.5 cm.In most cases,the highest alkaloid levels observed were almost three times those of the lowest.If plant protection applications are developed for the endophytic fungus,Neotyphodium gansuense,it will be necessary to be aware of the potential role of plant husbandry practices (e.g.,defoliation frequency and intensity) for reducing or enhancing levels of plant alkaloids.Similar husbandry factors may affect alkaloid levels in other Neotyphodium-grass associations,which would be interesting for further study.