Morphological and molecular characterization of musa germplasm including wild spcies and cultivars and selection of superior genotypes
| dc.contributor.author | Samarasinghe, W. L. G. | |
| dc.date.accessioned | 2024-09-10T05:44:47Z | |
| dc.date.available | 2024-09-10T05:44:47Z | |
| dc.date.issued | 2005 | |
| dc.description.abstract | Banana (Musa spp.) is the most important fruit crop in Sri Lanka and is identified as a species for genetic improvement. Genetic variability present in Musa spp. in the country is rich and needs characterization for its use in banana improvement. Genetic variability existing in commercial cultivars such as ' Ambon ' and 'Kolikuttu' also needs to be assessed for their genetic improvement. Characterization or estimation of genetic diversity at molecular level, using Simple Sequence Repeats (SSR) is a rapid and accurate technique complementary to morphological characterization. In this research, 27 Musa germplasm (M. acuminata, M. balbisiana, polyploids and interspecific hybrids), were characterized using SSRs and morphological characters. In addition, germplasms of ' Ambon ' and 'Kolikuttu' were explored, collected and analyzed using SSR primers. Morphological characterization of Musa generated useful information for clustering the germplasm. However, difficulties were faced in scoring morphological data as some character states were not discrete. Therefore, morphological characterization alone could lead to wrong conclusions. Specific SSR regions of Musa were amplified by P C R , using S S R primers (AGMI and M a S S R primers). P C R products were separated by P A G E and the bands were detected by both autoradiography ( P 33 labeling) and silver staining. U P G M A grouping of Musa germplasm using SSR data showed a certain extent of similarity to morphological grouping. Characterization by both morphological and S S R gave a better picture of the genetic relationship o f Musa cultivars and wild species in Sri Lanka. SSR primers MaSSR 20 a/b, MaSSR 18a /b, MaSSR 22dJb MaSSR 24 a/b, MaSSR 7a/b and AGMI 95/96 are useful for characterization o f distantly related Musa spp. in Sri Lanka. Musa spp. used in analysis showed a great extent of SSR diversity, which reflects a rich genetic diversity among them. Therefore, the gemplasm used in this research is recommended for conservation in the field and in-vitro. MaSSR 24ab can be used to differentiate inter-specific cultivars ( AAB or ABB ) from AA or AAA genotypes. SSR markers were used to identify ' Unel ' (AA), 'Navari' (AA), 'Barm' (ABB), ' Mondan ' (ABB) and Etikesel (BB) which are useful in cultivar identification and breeding. The wild spp. ' Unel ' (M. acuminata colla, AA ) is extremely diverse from the rest of the genotypes followed by ' Navari ' . Therefore, the possibility of ' Unel ' contributing genes into Sri Lankan cultivars is rather low in contrast to the other wild species 'Etikesel' ( M balbisiana colla). Fertile diploids viz. ' Unel ' , 'Etikesel' and ' Navari ' are distinct genotypes useful for genetic mapping and breeding. 'Muwanethikesel' is a possible mutant of ' Walsuwandel ' . ' Alukesel' and ' Etamuru ' which produce seeds occasionally are also unique genotypes useful in banana improvement. ' Puwalu ' and 'Seenikesel* are superior genotypes with respect to bunch, fruit and yield characters. These two genotypes were recommended for further evaluation and were morphologically characterized in detail. ' K olambaseeni1 is also a potential variety for commercial cultivation. Genetic variation between ' Ambon ' accessions observed was very little. Based on molecular and morphological data, two distinct genotypes: I. Typically long (> 20cm), strait and shiny fruits with brown strips on mature fruits and II. Typically short (<20 cm), curved and dull fruits, pigmented with no brown strips were identified. Accessions collected from Alawwa and Wattegama (in group I) were selected as superior ' Ambon ' accessions in terms of bunch characteristics. Morphological and molecular data suggest that considerable genetic variation exists within 'Kolikuttu' collected from different areas. In the germplasm collection, the genotypes 'Idal Puwalu ' (Synonym 'Athdath Kolikuttu'), 'Kuttipuwalu', Kotiyagala type in Siyambalanduwa and an ecotype in Samanthurai were identified. 'Kuttipuwalu' and 'Idal Puwalu' were identified as superior genotypes with respect to bunch characteristics. Kotiyagala type seems to be superior for pest, diseases and drought tolerance/resistance while Samanthurai accession may be superior for salinity and drought resistance. This information could be used in future exploration and collection of germplasm, characterization and evaluation of genetic resources of Musa in Sri Lanka. | |
| dc.identifier.uri | https://ir.lib.pdn.ac.lk/handle/20.500.14444/901 | |
| dc.language.iso | en_US | |
| dc.publisher | University of peradeniya | |
| dc.subject | Banana | |
| dc.subject | Musa spp | |
| dc.subject | Molecular characterization | |
| dc.subject | Morphological characterization | |
| dc.title | Morphological and molecular characterization of musa germplasm including wild spcies and cultivars and selection of superior genotypes | |
| dc.type | Thesis |