Location: Subtropical Horticulture ResearchTitle: Genetic diversity of mango cultivars estimated using Start Codon Targeted (SCoT) markers) Author
|Schnell Ii, Raymond|
Submitted to: Tree Genetics and Genomes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/28/2011
Publication Date: N/A
Citation: Interpretive Summary: Little is known about the genetic diversity in mango in China. Using a novel type of dominant marker called Start Codon Targeted (Scot) markers 23 mango germplasm accessions collected in different areas of Guangxi province in China were analyzed. The polymorphism rate using these markers was very high, 70.5%, and genetic relationships were estimated using a similarity coefficient between different pairs of accessions. The analysis revealed that the 23 mango accessions were closely related and group them into two main clusters. Within these clusters known pedigrees were well supported indicating that the breeding history of these cultivars was well documented. The data was also analyzed using principal coordinate analysis and this analysis also supported the known pedigree of the accessions. Based on these results, Scot markers are useful for germplasm management and allow the use of molecular markers in labs that cannot afford capillary electrophoresis genetic analyzers.
Technical Abstract: Diversity and genetic relationships among 23 mango germplasm accessions, collected from different locations in Guangxi province in China, were analyzed by using a novel and simple gene targeted DNA marker: Start Codon Targeted (SCoT) markers. This technique uses a single, 18-mer primer PCR amplification reaction with an annealing temperature of 50 degrees C. PCR amplification products are resolved using standard agarose gel electrophoresis. In this study, we designated 44 new primers, in addition to the originally reported 36 primers. Out of 80 available primers, 15 were selected for their reproducible and polymorphic DNA amplification patterns. A total of 132 clear and bright fragments were detected among accessions, with an average of 8.8 bands per primer, of which 93 were polymorphic, yielding a polymorphism rate of 70.5%. The percentage of polymorphism observed with SCoT markers indicated that a high level of genetic variation exists among the accessions. Genetic relationships estimated using similarly coefficient (Dicd) values between different pairs of accessions varied from 0.73 (between "Chuan Mango" and "Yunnan Si Mao Xiang Ya Mango') to 0.974 (between 'Guangzhou Xiang Ya Mango' and 'Gui Ke No.5) with an average of 0.819. The unweighted pair-group method of arithmetic averages (UPGMA) cluster analysis, based on genetic similarity coefficients, produced a dendrogram which grouped the 23 accessions into two main clusters. The data was also analyzed using principal coordinate analysis (Poi) which accounted for 44.9% of the total variation. The result of cluster analysis and Poi was generally in agreement with the known breeding pedigrees.