Genetic Divergence in Mango and Obtaining Minimum Efficient Descriptors

Abstract

Mangifera indica (mango) is a typically tropical fruit with considerable economic value. Brazil features a wide variety of cultivars of this fruit, most of which are known under several different names. Indeed, the nomenclature of mango varieties is still quite confusing. Up to now there has been no well-defined scientific principle to differentiate them. The objective of the present work is to compare the different clustering methods in assessing genetic divergence among mango accessions, as well as identify the minimum efficient descriptors for that crop. A total of 20 mango accessions in Cáceres, Mato Grosso state, Brazil were evaluated. When building dissimilarity matrices, the descriptors were divided according to the following groups: leaf, flower/inflorescence, fruit, seed and growth habit/ripening period. With these divisions, combinations were performed among the groups of descriptors. The similarity index was used to obtain the dissimilarity matrices. Later, the accessions were clustered using the methods of Tocher, Ward and UPGMA. The study observed that it was possible to reduce the number of descriptors from 64 to 35, and that the clustering methods were compatible with the study of the genetic diversity of mango.

Genetic divergence among maize hybrids in cerrado-pantanal ecotone

“…The dissimilarity among hybrids established by UPGMA method based on the arithmetical mean of dissimilarity measures is a tool that associated with Tocher's optimization method provides greater safety in discriminating different genotypes to genetic divergence. Both cluster methods similarly have hybrids allocated in groups with greater genetic similarity, a fact that has also been observed by other authors (SMITH et al 1997;OLIVEIRA et al, 2010;ROTILI et al 2012;SIMON et al 2012;PREISIGKE et al 2013 andGOMES JÚNIOR et al 2014). The most divergent hybrids according to Mahalanobis's distance (D²=4.20) were XB6012 and MAXIMUS, which were also allocated into different groups (groups V and II) by Tocher's method.…”

Phenotype characterization and diversity assessment of mango (Mangifera indica L.) cultivars in Ethiopia

“…Phenotype characterization is the first step before biochemical and molecular markers due to its simplicity, low-cost requirement, standardized, repeatable method and availability of published descriptors for most major crops (Khan et al, 2015;Mohamed and Ahmed, 2015;Ravani and Joshi, 2013). In the last decade, various phenotype markers have been successfully applied in determining the intra cultivar diversity of mango in different parts of the world (Ahmed and Mohamed, 2015;Mohamed and Ahmed, 2015;Preisigke et al, 2013;Rajwana et al, 2011;Rymbai et al, 2014). However, such vital studies have not been conducted on mango in Ethiopia that is on the verge of extinction.…”