Determination of Chromosome Organization and Dynamics during Meiosis in Musa Species

Loke, Ting Yau (2018) Determination of Chromosome Organization and Dynamics during Meiosis in Musa Species. Final Year Project (Bachelor), Tunku Abdul Rahman University College.

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Abstract

All banana fruit cultivated for thousands of years are from two decent wild type banana Musa Acuminata and Musa Balbisiana. Wild type banana usually have two set of chromosome (2N) known as diploid. While commercially available banana have extra set of chromosome known as polyploidy. The presence of additional sets of chromosomes in cell nuclei can have various effects on an organism as they will disrupt the normal processes of cell division and causing the crops to be sterile. Furthermore, seedless banana will cause significant reduction of the genetic diversity and reduce the ability to resistance to pest or diseases. The aim of this project was to determine the chromosome organization and dynamics during meiosis between Wild Musa species and cultivars. 5s rDNA and 45s rDNA were examined in three Musa cultivars and wild type Musa species. 45s rDNA primers were designed from partial sequence of Musa Acuminata while 5s rDNA primers were designed from partial sequence of Musa balbisiana. PCR result showed that two sample were successfully clone by using 45s rDNA primers but not in the 5s rDNA primers indicating that all samples are AA or AAA Musa cultivar group. Then, pollen staining by using Alexander’s stain protocol was conducted to observe the pollen viability under microscope. The percentage of not viable pollen are high in Musa cultivar compared to wild type. Besides that, abnormal size and morphology pollen was observed. Slides of digested banana anthers using 0.33% enzyme mix were prepared and observed under fluorescent microscopy to determine the chromosome movement and dynamics during meiosis. From the observation, the present of abnormal chromosome segregation and morphology was observed. As conclusion, the production of sterile banana was causing by missegregation of chromosome during early meiosis. Karyotyping of chromosome and utilizing FISH probes to observe the mismatching and missegregation chromosome may be a need for further studies.