濒危植物秀丽兜兰叶绿体基因组特征与系统发育分析

秀丽兜兰(Paphiopedilum venustum)具有较高的观赏价值和保护生物学价值,野外资源濒临灭绝,叶绿体基因组(cpDNA)具有基因组小、结构稳定、高度的保守性等优点被广泛用于植物系统发育和物种鉴定,了解秀丽兜兰的叶绿体基因组结构,对揭示兜兰属植物的系统进化关系具有重要意义。本研究通过二代高通量测序技术获得秀丽兜兰叶绿体全基因组序列,利用GeSeq、blast和hmmer软件对叶绿体基因组进行注释,采用MISA、CodonW、fasttree等生物信息学软件对其基因组结构、基因数目、序列重复、密码子偏好性和系统发育进行分析。结果表明:秀丽兜兰叶绿体基因组结构保守,具有典型的环状四分体结构,一对反向重复区(IRs)将大单拷贝区(LSC)和小单拷贝区(SSC)分开,全长158298 bp,GC含量为35.4%,共注释得到129个基因,包括79个蛋白编码基因,38个tRNA基因、8个rRNA基因和4个假基因;检测到78个SSR位点,以单核苷酸重复和二核苷酸重复为主,分别占84.62%和10.26%,无五核苷酸重复,并且大多由A或T构成;确定了高频密码子32个,90.6%都以A或U结尾,编码亮氨酸(Leu)的密码子使用频率最高,而编码半胱氨酸(Cys)的密码子使用频率最低。通过比较18个兰科植物叶绿体基因组,构建系统进化树发现,紫花杓兰和西藏杓兰2个杓兰属植物被单独聚成一支,兜兰属被分成两大类,其中秀丽兜兰(P.venustum)与同属的紫纹兜兰(P.purpuratum)亲缘关系密切。本研究筛选出的SSR和核苷酸多态性能够作为兜兰属植物种质鉴定和遗传多样性的分子标记,可为珍稀濒危植物秀丽兜兰及其近缘种的种质鉴定、系统发育等提供理论依据,为兜兰属植物种群恢复、生物多样性保护、创新利用及新品种选育奠定基础。

杀虫剂处理衣服对伊蚊和蚋防护效果观察

目的研究氯菊酯以及氯菊酯与避蚊胺复配的杀虫剂处理衣服对刺扰伊蚊和班布蚋的防护效果。方法用2种剂量的药物浸泡迷彩服,通过强迫接触法进行击倒时间的观察;用2种剂量的药物浸泡蚊帐,并设空白对照,在野外通过人帐诱法,观察其防护效果;在野外穿着药物处理过的服装观察对蚊、蚋的防护效果。结果强迫接触试验中对班布蚋的击倒时间剂量1的KT50为2.110 min,剂量2的KT50为2.760min,对刺扰伊蚊的击倒时间,剂量1的KT50为6.826 min,剂量2的KT50为7.757 min;人帐诱试验剂量1对蚊蚋的防护效果为88.17%～88.64%,剂量2对蚊蚋的防护效果为92.90%～93.26%;在野外防护效果试验中,穿着实验室浸泡的衣服,剂量1对蚊、蚋的保护率为84.51%～92.19%,剂量2对蚊、蚋的保护率为90.14%～95.31%,现场对衣服进行喷雾,剂量1对蚊、蚋的保护率为91.55%～95.31%,剂量2为94.37%～96.89%。结论用0.80%的氯菊酯以及0.50%氯菊酯和5.21%避蚊胺复配药物2种剂量浸泡衣服或使用前对衣服进行喷雾,在野外活动时都能有效地防护刺扰伊蚊和班布蚋的叮咬。

Fern extracts potentiate fluconazole activity and inhibit morphological changes in Candida species

Objective: To investigate the antifungal activity of the fern species Lygodium venustum(L. venustum) and Pityrogramma calomelanos(P. calomelanos) against Candida albicans and Candida tropicalis strains.Methods: The microdilution method was used to evaluate the antifungal activity, as well as the modulating effects of ethanolic extracts of these plants in combination with fluconazole. The minimum inhibitory concentration(MIC), minimum fungicide concentration and morphological changes were also determined.Results: The extract obtained from L. venustum presented a MIC > 8 192 mg/m L, while the extract obtained from and P. calomelanos presented a MIC = 8 192 mg/m L, indicating that they present weak antifungal activity. However, combination of the extracts with Fluconazole potentiated the antifungal activity of this drug. At different experimental conditions, such as concentration of the extract and type of strain, the extracts inhibited hyphae and pseudohyphae formation, indicating that these fern species can affect the morphology of the fungi.Conclusions: The extracts obtained from the fern species L. venustum and P. calomelanos dose not present significant antifungal activity. However, P. calomelanos potentiates the activity of fluconazole and both extracts inhibits the morphological changes in Candida species, indicating that they have potential pharmacological activity as modulators of fungal biology. Therefore, novel studies are required to characterize the interference of these extracts in the virulence and pathogenicity of Candida species as well as the potential of fern species to treat fungal infections.

中国云南蚋亚属Simulium一新种(双翅目:蚋科)

记述采自云南省蚋属Simulium蚋亚属Simulium脉蚋组venustum1新种,以腹部特征命名为毛腹蚋Simulium(Simulium)setiferorum sp.nov.,对其雌虫特征进行了描述。该新种与来自中国辽宁的新宾蚋S.(S.)xinbinen Sun,1994形态相似,但新种的生殖器与上述蚋种明显不同。文章还编制了中国蚋亚属脉蚋组雌虫的分种检索表。