PG Research Centre, Department of Botany, Modern College of arts, Science and Commerce, Shivajinagar, Pune, Maharashtra, India 411 005.
Indian J Microbiol. 2007 Sep;47(3):212-8. doi: 10.1007/s12088-007-0042-6. Epub 2007 Oct 4.
Ravenelia esculenta Naras. and Thium. is a rust fungus, which infects mostly thorns, inflorescences, flowers and fruits of Acacia eburnea Willd. Aecial stages of the rust produce hypertrophy in infected parts. DNA of the rust fungus was isolated from aeciospores by 'freeze thaw' method. 18S rDNA was amplified and sequenced by automated DNA sequencer. BLAST of the sequence at NCBI retrieved 96 sequences producing significant alignments. Multiple sequence alignment of these sequences was done by ClustalW. Phylogenetic analysis was done by using MEGA 3.1. UPGMA Minimum Evolution tree with bootstrap value of 1000 replicates was constructed using these sequences. From phylogenetic tree it is observed that Ravenelia esculenta and the genus Gymnosporangium share a common ancestry, though Ravenelia esculenta is autoecious on angiosperm and the genus Gymnosporangium is heteroecious with pycnia, aecia on angiosperm and uredia, telia on gymnosperm. Two major clades are recognized which are based on the nature of aecial host (gymnosperm or angiosperm). These clades were also showing shift from pteridophytes to angiosperms as telial hosts. The tree can be interpreted in the other way also where there is separation of 14 families of Uredinales depending upon nature of teliospores, nature of aeciospores and structure of pycnia. These studies determine the phylogenetic position of Ravenelia esculenta among other rust fungi besides broad separation of Uredinales into two clades. These studies also show that there is phylogenetic correlation between molecular and morphological data. This is first report of DNA sequencing and phylogenetic positioning in genus Ravenelia from India.
糙皮侧耳锈菌是一种感染金合欢属植物的刺、花序、花和果实的锈菌。锈菌的夏孢子阶段会导致感染部位的增生。采用“冻融”法从夏孢子中分离出锈菌的 DNA。通过自动 DNA 测序仪对 18S rDNA 进行扩增和测序。在 NCBI 上对序列进行 BLAST 检索，得到了 96 个产生显著比对的序列。使用 ClustalW 对这些序列进行多序列比对。通过 MEGA 3.1 使用 UPGMA 最小进化树，基于 1000 次重复的自举值构建了基于这些序列的系统发育树。从系统发育树中可以看出，糙皮侧耳锈菌和 Gymnosporangium 属具有共同的祖先，尽管糙皮侧耳锈菌在被子植物上是自交的，而 Gymnosporangium 属在被子植物上是异交的，具有 Pycnia、Aecia 和 Uredia、Telia。根据夏孢子宿主（裸子植物或被子植物）的性质，识别出两个主要的分支。这些分支也显示出从蕨类植物向被子植物作为 Telial 宿主的转变。该树也可以从另一个角度解释，即根据厚垣孢子的性质、夏孢子的性质和 Pycnia 的结构，将 Uredinales 分为 14 个科。这些研究确定了糙皮侧耳锈菌在其他锈菌中的系统发育地位，同时将 Uredinales 广泛分为两个分支。这些研究还表明，分子和形态数据之间存在系统发育相关性。这是印度糙皮侧耳锈菌 DNA 测序和系统发育定位的首次报道。
