古尼虫草核苷类成分的高效液相色谱分析

以已知核苷为标样,并以冬虫夏草做对比,利用反相高效液相色谱法对古尼虫草及其发酵菌丝体的核苷类化学成分进行了分析,结果表明古尼虫草和冬虫夏草主要含有7种标样核苷中的腺苷、胞苷、尿苷,其含量相当,而古尼虫草发酵菌丝体中腺苷和尿苷的含量是古尼虫草子座或僵虫体的2～3倍。     

古尼虫草核苷类成分的高效液相色谱分析*

以已知核苷为标样,并以冬虫夏草做对比,利用反相高效液相色谱法对古尼虫草及其发酵菌丝体的核苷类化学成分进行了分析,结果表明古尼虫草和冬虫夏草主要含有7种标样核苷中的腺苷、胞苷、尿苷,其含量相当,而古尼虫草发酵菌丝体中腺苷和尿苷的含量是古尼虫草子座或僵虫体的2~3倍。     

蛹虫草病原真菌虫草生齿梗孢Calcarisporium cordycipiticola的生物学特性研究

蛹虫草已经成为我国乃至东南亚地区极其重要的食药用真菌,虽然其子实体已经实现规模化生产,但在产业发展中遇到许多问题,真菌病害为其中之一,如引起蛹虫草“白毛病”病害的虫草生齿梗孢Calcarisporium cordycipiticola。本研究以虫草生齿梗孢为对象,研究了其生物学特性、发病特性及侵染特点。结果表明：该病原菌菌丝分枝较多,短时间内产生大量分生孢子;最适生长温度为25℃,此温度有利于该病害快速传播;其分生孢子比蛹虫草分生孢子耐紫外能力强。栽培过程中该病害多发生在蛹虫草生长发育后期,可以侵染培养基表面、子实体底部、中部和顶端等各个部位。人工接种发现该病原菌可以侵染蛹虫草生长发育的任意阶段,后期子实体被白毛覆盖。对峙实验发现虫草生齿梗孢菌丝逐渐生长到蛹虫草菌丝上,但未发现两菌丝互相缠绕的现象。对该病原菌基本生物学研究,将为建立该病害的早期检测及预防方法提供依据。     

不同种质资源蛹虫草菌丝生长特性及其多糖产量的研究

研究本试验中6株不同来源的蛹虫草菌株(150707,150715,150725,150808,52244,51762)的菌丝生长特性及其多糖产量。测定这6株蛹虫草菌丝生长速度、分生孢子产量,利用水提醇沉法提取不同菌株粗多糖。研究发现在不同培养基上不同来源的这6株蛹虫草菌丝生长速度、产分生孢子量、多糖得率不同,在加富PDA培养基上生长速度较快,但是在血平板培养基上孢子产量及多糖得率较优。分析得出150707、52244两个菌株孢子产量和多糖产量相对较高,为优势菌株,血平板培养基为蛹虫草孢子及多糖产量较优培养基。     

蓝光和蛋白酶体抑制剂MG132对蛹虫草形态的影响

蓝光是影响生物生长发育过程的重要因素,同时生物个体的生长发育过程中不断有蛋白质的泛素化降解。采用蓝光和蛋白酶体抑制剂MG132处理蛹虫草菌,观察蛹虫草菌落、菌丝体和子实体形态的变化。研究结果表明,黑暗条件下正常生长的菌落边缘圆滑一致,菌落之间融合无边界;MG132处理后,菌落之间出现明显的界限,边缘菌丝稀疏。蓝光条件下无MG132处理时,菌落较为单薄,转色明显;MG132处理时,菌落中间橙色,边缘颜色变淡。扫描电镜观察,黑暗条件下无MG132处理的菌丝自然弯曲,菌丝表面较为光滑,菌丝粗细差别不大且分枝较少,分生孢子表面较光滑。黑暗条件下MG132处理菌丝体,菌丝较直且分枝较多,菌丝容易断裂,分生孢子表面仍较光滑。蓝光条件下菌丝体弯曲减少,菌丝表面较为粗糙,单条菌丝常出现部分区段膨大呈不规则状,菌丝粗细差异较大,菌丝断裂较多;分生孢子呈扁平的椭圆状,表面有纹理,且粗糙。蓝光条件下MG132处理的菌丝体,菌丝较直,表面粗糙,菌丝整体变得更细,菌丝断裂较多;分生孢子呈不规则形状,表面纹理更深,粗糙有褶皱。此外,MG132可导致蛹虫草子实体畸形生长。结果表明,蓝光和MG132均可以影响蛹虫草的形态变化。     

古尼虫草无性型的分子鉴别

采用PCR技术,以rDNA的ITS区为分子指标,对古尼虫草Cordycepsgunnii的有性和无性阶段进行比较分析,从分子水平上证明古尼虫草的无性阶段是古尼拟青霉Paecilomycesgunnii。     

古尼虫草与亚香棒虫草亲缘关系初探

目的：用分子生物学方法,对古尼虫草和亚香棒虫草进行研究,对其寄主昆虫COI（cytochrome oxidase subunit I,细胞色素氧化酶亚基I）和真菌ITS（Internal Transcribed Sequence,内转录间隔区）区的基因序列进行比较,以确定两者亲缘关系。方法：在古尼虫草和亚香棒虫草性状研究的基础上,对两者来源真菌ITS区和寄主昆虫COI基因进行了PCR扩增和序列测定,对序列进行比对分析,并与GenBank核酸序列数据库中的序列进行BLAST检索比对。结果：发现古尼虫草和亚香棒虫草的来源真菌ITS区和寄主昆虫COI基因序列均有较高相似度。结论：古尼虫草和亚香棒虫草有较近的亲缘关系。     

古尼虫草与亚香棒虫草亲缘关系初探

目的:用分子生物学方法,对古尼虫草和亚香棒虫草进行研究,对其寄主昆虫CO(Icytochrome oxidase subunit I,细胞色素氧化酶亚基I)和真菌ITS(Internal Transcribed Sequence,内转录间隔区)区的基因序列进行比较,以确定两者亲缘关系。方法:在古尼虫草和亚香棒虫草性状研究的基础上,对两者来源真菌ITS区和寄主昆虫COI基因进行了PCR扩增和序列测定,对序列进行比对分析,并与GenBank核酸序列数据库中的序列进行BLAST检索比对。结果:发现古尼虫草和亚香棒虫草的来源真菌ITS区和寄主昆虫COI基因序列均有较高相似度。结论:古尼虫草和亚香棒虫草有较近的亲缘关系。     

两种虫草无性型的微循环产孢确证

从贵阳地区采得两种虫草,古厄虫草Cordycepsgunnii（Bark．）Berk．和布氏虫草CordycepsbrongniartiiShimazu。经诱发它们子囊孢子的微循环产孢再次确证了古尼虫草的无性型是古尼拟青霉PaecilomycesgunniiLiang,布氏虫草的无性型是布氏白僵菌Beauveriabrongniartii（Sacc．）Peteh。     

两种虫草无性型的微循环产孢确证

从贵阳地区采得两种虫草,古尼虫划Ｂｅｒｋ．和布氏虫草Ｃｏｒｄｙｃｅｐｓ ｂｒｏｎｇｎｉａｒｔｉｉ Ｓｈｉｍａｚｕ。经诱发它们子囊孢子的微循环产孢再次确证了古尼虫草无性型是经拟青霉Ｐａｅｃｉｌｏｍｙｃｅｓ ｇｕｎｎｉｉ Ｌｉａｎｇ,布氏虫草的无性型是布氏白僵菌ＢｅａｕｖｅｒｉａｂｒｏｎｇｎｉａｒｔｉｉＰｅｔｃｈ。     

Spore Discharge in Deightoniella torulosa (Syd.) Ellis

Violent spore discharge in the Hyphomycete Deightoniella torulosais described. On drying, a negative pressure develops in thesolution inside the swollen head of the conidiophore. This causesthe thin wall at the top of the conidiophore to cave inwardsand to be brought into a state of tension. The sudden appearanceof a gas phase in the conidiophore head releases this tension,and the wall rapidly returns to its original rounded shape.The conidium, which is attached to the top of the conidiophore,is thus catapulted away. This appears to be the first recordof a gas phase being associated with violent spore dischargein a fungus.     

Visualizing nuclear migration during conidiophore development in Aspergillus nidulans and Aspergillus oryzae: multinucleation of conidia occurs through direct migration of plural nuclei from phialides and confers greater viability and early germination in Aspergillus oryzae

Nuclear migration is indispensable for normal growth, differentiation, and development, and has been studied in several fungi including Aspergillus nidulans and Neurospora crassa. To better characterize nuclear movement and its consequences during conidiophore development, conidiation, and conidial germination, we performed confocal microscopy and time-lapse imaging on A. nidulans and Aspergillus oryzae strains expressing the histone H2B-EGFP fusion protein. Active trafficking of nuclei from a vesicle to a phialide and subsequently into a conidium provided the mechanistic basis for the formation of multinucleate conidia in A. oryzae. In particular, the first direct visual evidence on multinucleate conidium formation by the migration of nuclei from a phialide into the conidium, rather than by mitotic division in a newly formed conidium, was obtained. Interestingly, a statistical analysis on conidial germination revealed that conidia with more nuclei germinated earlier than those with fewer nuclei. Moreover, multinucleation of conidia conferred greater viability and resistance to UV-irradiation and freeze-thaw treatment.     

人工发酵古尼虫草中甘露醇的测定

利用比色法简便、准确和快速地测定发酵生产的古尼虫草菌丝中甘露醇含量。结果表明 ,甘露醇的最大特征吸收峰在 41 2nm处 ,质量浓度在 1 0～ 5 0mg/L范围内线性较好 ,其回归方程 ρ=-0 842 +97 3 2 9A,r=0 9992 ;平均回收率 1 0 0 2 4% ,RSD =0 5 4% (n=5 )。样品中甘露醇采用水提取法 ,提取时间 2h。甘露醇显色后 2 0min内测定对结果影响不大 ,在测定时要注意排除果糖对测定结果的影响。用此法测得发酵古尼虫草菌丝体中甘露醇的含量为 7.4% ,RSD =0 .2 4% (n =6)。     

古尼虫草的生物活性物质I含肽镇痛组分的分离及性质

用理化分离分析和生物检测方法相结合,从古尼虫草(Cordyceps gunnii(Berk.)Berk.)无性型,古尼拟青霉(Paecilomyces gunnii Liang)菌丝体中初步分离纯化得到镇痛物质,该物质经氨基酸组成分析表明是一种酸性氨基酸残基高的肽类物质。经不同温度、pH及蛋白酶的稳定性试验分析观察到这种肽类物质对酸稳定、在酸性条件下抗热,对胃蛋白酶、胰蛋白酶部分敏感,对蛋白酶K不敏感。经小鼠竖尾法和大鼠攻击法测定,无吗啡类药物依赖性。     

Consecutive monitoring of lifelong production of conidia by individual conidiophores of Blumeria graminis f. sp. hordei on barley leaves by digital microscopic techniques with electrostatic micromanipulation

Conidial formation and secession by living conidiophores of Blumeria graminis f. sp. hordei on barley leaves were consecutively monitored using a high-fidelity digital microscopic technique combined with electrostatic micromanipulation to trap the released conidia. Conidial chains formed on conidiophores through a series of septum-mediated division and growth of generative cells. Apical conidial cells on the conidiophores were abstricted after the conidial chains developed ten conidial cells. The conidia were electrically conductive, and a positive charge was induced in the cells by a negatively polarized insulator probe (ebonite). The electrostatic force between the conidia and the insulator was used to attract the abstricted conidia from the conidiophores on leaves. This conidium movement from the targeted conidiophore to the rod was directly viewed under the digital microscope, and the length of the interval between conidial septation and secession, the total number of the conidia produced by a single conidiophore, and the modes of conidiogenesis were clarified. During the stage of conidial secession, the generative cells pushed new conidial cells upwards by repeated division and growth. The successive release of two apical conidia was synchronized with the successive septation and growth of a generative cell. The release ceased after 4-5 conidia were released without division and growth of the generative cell. Thus, the life of an individual conidiophore (from the erection of the conidiophore to the release of the final conidium) was shown to be 107 h and to produce an average of 33 conidia. To our knowledge, this is the first report on the direct estimation of life-long conidial production by a powdery mildew on host leaves.