粒毛盘菌属及其相关属的分子系统学研究

晶杯菌科的分类目前主要基于子囊盘外囊盘被表面毛状物的形态学特征,在系统演化关系上十分不清楚。本研究利用18SrRNA基因核苷酸序列分析方法探讨该科粒毛盘菌属及其相关属间的系统发育关系。以Saccharomycescerevisiae为外群的严格合意树和最简约树表明,粒毛盘菌属与其相关的属形成三个分支。Lachnumhyalopus,L.nudipes和L.virgineum代表一个分支。L.brasiliense,L.sclerotii,L.singerianum,Albotrichaguangxiensis,Calycellinapopulina.,Cistellagrevillei,Hyaloscyphaaureliella,Lachnellulacalyciformis,Parachnopezizaguangxiensis和Trichopezizasulphurea聚在一起(支持率为57%),为另一个分支。上述两个姊妹分支的支持强度为76%。与Lachnum在形态上有些相似的Cistella和Lachnum聚在一起的支持强度为51%。传统上纳入Arachnopezizoideae的Parachnopeziza与该亚科的模式属Arachnopeziza的关系较远。Arachnopezizaaurata是供试的14个种中距离最远的一个,位于系统发育树的最外侧,与上述两个分支的亲缘关系较远,这对Arachnopezizoideae在晶杯菌科中的地位提出了质疑。

1株海洋真菌ZH2.1的鉴定及生物学特性初步研究

从南海海域白姑鱼消化道分离到1株海洋真菌ZH2.1,对其进行了系统鉴定和生物学研究。采用传统的形态学鉴定方法,并结合18S rDNA序列分析确定其归属。18S rDNA序列分析表明其与孔状短小茎点霉Phoma exigua var.exigua在进化位置上最为接近,其18S rDNA在GenBank的登录号为FJ450059。结合形态学观察结果,可认为菌株ZH2.1为茎点霉属真菌。对该菌株的部分生物学特性研究表明,ZH2.1为兼性海洋真菌,最适生长盐度为3%。此外,在微氧条件下也可生长。

Mrakia psychrophila sp.nov.,a new species isolated from Antarctic soil

The yeast strain （Y18） was isolated from a soil sample collected from Fildes Peninsula, Antarctica. The strain is a psychrophilic yeast with optimum and maximum growth temperatures of 10 ℃ and 18 ℃, respectively. Teliospores were formed after 7 d on malt agar, when the germination of teliospores was observed. Both inositol and D-glucuronate were assimilated. Positive results of the DBB （diazonium blue B） color reaction, urease test, and starch formation were observed. The major CoQ is Qs. All results indicated that Y18 belongs to the genes of Mrakia. The 18S rDNA sequence analyses showed that Y18 is closely related to Mrakiafrigida. DNA-DNA relatedness study, and some biochemistry characteristics indicated that Y18 represents a new species for which Mrakia psychrophila sp. nov. is proposed.