Study On Morphological And Molecular Systematics Of China Mostly Musa Germplasm

Musa nana Lour., belonging to Musa of Musaceae, is one of the most important fruit throughout the world. Musa nana initially originated from tropical regions of southwest Asia, and now it is widely distributed in tropical and subtropical regions of the world. China is not only one of the originating centers of Musa nana, but also has rich and diverse germplasm, containing wild species of Musa and cultivars of bananas. However the research of genetic diversity and identification has not well developed. In this research, the technique of ISSR molecular markers and morphological characters were firstly used to identify and classify Musa germplasms of wild species of Musa and some special cultivars of bananas from Southern subtropical Crop Research Institute of CATAS, and to analyze their genetic relationship, identify their classification status, and to set up their fingerprinting, which could supply evidences for preservation, protection and utilization of Musa germplasms.According to the morphological traits (Simmonds N.W.,1955,1962 ) for cultivars and wild species of Musa, Eight cultivars with different ploidy and genomic composition in this research were divided into three types: AA, AA and AAAB. Twelve wild species belonged to only two groups in Musa: Australimusa and Eumusa. And Eumusa had eleven Musa germplasms, one was M.itinerans, two were M.balbisiana, and eight were M.itinerans. Australimusa only had one Musa germplasm, which was M.maclayi. In addition, four cultivars (AAAB and AAA) came aboard.DNA of Musa extracted by improved CTAB method could be used in ISSR amplification, and the resolution and multiple polymorphic bands could be obtained.In this study, orthogonal design was used to optimize ISSR amplification system on Musa in four factors (dNTPs, template DNA, Taq DNA polymerase and primers) at three levels respectively. The optimal annealing temperature of every primer and the cycles for ISSR-PCR reaction were proposed by gradient PCR. And a suitable ISSR reaction system was established, namely 25ul reaction system containing 1×PCR buffer, 2.0mmol/L Mg²⁺Cl, 0.15μmol/L dNTPs, 1.2SVTaq DNA...