检疫性杂草皱匕果芥的研究进展

从检疫性杂草皱匕果芥对除草剂抗性的现状和机制,影响种子萌发和出苗的因素,出苗时间对生长和繁殖的影响,潜在利用和控制策略等方面介绍了国内外对皱匕果芥的研究进展,指出了目前我国皱匕果芥检疫管制措施存在的问题,提出目前应从加强疫情监测、增补列入进境检疫名录、加强检疫监管和防控宣教等方面做好皱匕果芥的综合防控。     

血芝液体深层发酵合成三萜类化合物的条件优化

[目的]探究血芝液体深层发酵合成三萜类化合物的最佳发酵条件。[方法]先以单因素试验分析碳源、氮源、转速、p H、接种量对血芝液体深层发酵合成三萜类化合物的影响,选取其中3个主要影响因素,采取响应面分析法进一步优化血芝液体深层发酵合成三萜类化合物的最佳工艺条件。[结果]单因素试验结果显示,血芝发酵合成胞内三萜类化合物的最适条件为p H=6,转速为130 r/min,最适碳源为蔗糖,最适氮源为尿素。响应面法优化的发酵条件为3%接种量、30 g/L蔗糖、1.9 g/L尿素,血芝三萜类化合物含量达16.51mg/g。[结论]该研究为血芝活性成分的研究提供实际参考依据。     

木麻黄茎腐病病原菌的鉴定及其生物学特性测定

通过对海南种植的木麻黄上发生的茎腐病病原菌进行致病性测定、形态学特征鉴定和ITS序列分析,确认引起海南木麻黄茎腐病的病原菌为二孢假芝[Amauroderma subresinosum (Murrill) Corner]。生物学特性测定结果显示,黑暗可以促进菌丝生长,菌丝最适生长温度为32 ℃,最适pH为6.0,蔗糖和大豆蛋白胨为最佳碳源和氮源。     

台湾相思假芝根腐病病原菌的鉴定及其生物学特性测定

对海南台湾相思上一种假芝属真菌所致根腐病病原菌进行致病性测定、形态学特征鉴定和SSU序列分析,确认引起海南台湾相思此种根腐病的病原菌为假芝[Amauroderma rugosum (Bl.et Nees) Torrend]。生物学特性测定结果表明：光照可以促进其菌丝生长,菌丝最适生长温度为32 ℃,最适pH为5,D-果糖和酵母浸膏为最佳碳源和氮源。     

中国海南台湾相思树干基腐朽病

海南省台湾相思树(Acacia confusa Merr．)干基腐朽病为中国一种新的林业病害，其病原菌为热带灵芝(Ganoderma tropicum(Jungh．)Bres．)和粗柄假芝(Amauroderma elmerianum Murrill．)本研究根据野外调查对此新病害的症状进行了报道，并根据实地采样对这两种新的病原菌进行了详细描述。     

Seed germination, seedling establishment and growth patterns of wrinklegrass (Ischaemum rugosum Salisb.)

Several laboratory and glasshouse experiments were conducted to assess seed germination, seedling establishment and growth patterns of wrinklegrass (Ischaemum rugosum Salisb.) influenced by temperature and light regimes, and chemical media. Wrinklegrass was a positively photoblastic species, and seed germination was temperature‐dependent and light‐mediated. Seeds soaked in distilled water for 24 h, or oven‐dried at the respective temperature regimes of 15, 20, 25, 30, 35, or 40°C prior to treatment in distilled water and incubated in darkness, failed to germinate. Likewise, no germination prevailed when the seeds were exposed to similar temperature regimes and treated with 0.2 m KNO₃, 5% H₂O₂ or 0.01 m HNO₃, and incubated under continuous darkness. Seeds treated with 5% H₂O₂ at 30°C, or oven‐dried and treated with 0.01% M HNO₃ at 35°C registered 10 and 20% germination. Approximately 75 and 90% of the light‐exposed seeds for all treatments germinated in the first three and six days at 25°C. No germination occurred at 15°C in the first three days after treatment. Seeds subjected to 40°C for six days after treatment recorded 36% germination. The optimum temperatures for seed germination were 25–30°C. Seed drying and soaking treatments widened the windows of the optimal temperatures for wrinklegrass germination. The acidic media of KNO₃, H₂O₂ or HNO₃ favored seed germination. Less than 5% of seed germination occurred with burial or water inundation at depths exceeding 2 cm. Seed burial or inundation at ≥2 cm depths inhibited seed germination. Seeds sown onto moist paddy soils registered ca. 50% germination. Free‐floating seeds on the water surface registered ca. 98% germination within the first six days after seeding. The mean number of seedlings that survived was inversely proportional to water depths, with close to 100% mortality at the 14 cm depths of inundation. Both plant height and seedling survival were linearly proportional to the amount of root mass of seedlings which penetrated the soil. The weed was a prolific seed producer (ca. 6000 seeds/genet or 18 000 seeds/genet per year). The vegetative and reproductive efforts of each wrinklegrass plant registered values of 0.68 and 0.32, respectively.     

假芝子实体粗多糖组成及抗氧化和免疫活性研究

【目的】提取假芝子实体多糖,研究其粗多糖组成及其抗氧化活性等,为假芝资源开发利用提供参考。【方法】以人工驯化栽培的假芝子实体为材料,采用热水浸提法,经脱蛋白、冷冻干燥获得粗多糖,采用 HPLC、GPC、凯氏定氮法等分析多糖组分、分子量和蛋白质、氨基酸组成,检测假芝多糖清除羟基自由基、ABTS 自由基抗氧化活性,用 MTS 法检测假芝多糖对巨噬细胞 RAW264.7 增殖的影响。【结果】假芝子实体粗多糖为棕褐色粉末,当浓度为 1.5 mg/mL 时羟基自由基、ABTS 自由基清除率分别达 90.26%、83.95%,一定范围内能促进 RAW264.7 巨噬细胞的增殖。假芝子实体多糖蛋白质含量为 16.99%,含有 17 种氨基酸,其中必需氨基酸占 28%,以天冬氨酸和谷氨酸含量最高,二者占比超过 30%。多糖组分由半乳糖、岩澡糖等 10 种单糖组成,其中半乳糖、葡萄糖、甘露糖含量最高,3 种单糖含量占 67.87%。假芝粗多糖数均分子量（Mn）为 28.239 ku,重均分子量（Mw）为 57.502 ku,分布系数 α（Mw/Mn）为 2.036。【结论】假芝粗多糖为含有蛋白质的杂多糖,对羟基自由基、ABTS 自由基清除效果好,为更好的推广应用和科学开发假芝提供了科技支撑。