Molecular characterization of Portuguese pear landraces (Pyrus communis L.) using SSR markers
2014; Elsevier BV; Volume: 183; Linguagem: Inglês
10.1016/j.scienta.2014.11.016
ISSN1879-1018
AutoresÁlvaro Antônio Alencar de Queiroz, Augusto Assunção, Ilda Ramadas, Wanda Viegas, Manuela Veloso,
Tópico(s)Plant Physiology and Cultivation Studies
ResumoA very rich heritage of pear (Pyrus communis) landraces is still maintained in Portugal. In this work, we present the molecular characterization of 48 accessions from the national reference collection at Vidago and Felgueiras. The core set of six microsatellite markers recommended by the European Cooperative Programme for Plant Genetic Resources was used. Thirty-six distinct genotypes were scored since several synonymies were found and three homonymous cultivars were detected. Three cultivars were found to be triploids. The average expected heterozygocity was high (0.806), and the number of alleles found averaged 11.3/locus. Effective allele number ranged from 3.3 to 9.0. Marker CH05c06 was the least informative while marker CH01f07a was the most informative, with a polymorphic information content (PIC) of 0.675 and 0.876, respectively. Cluster analysis of the molecular data grouped the accessions in eight classes: two groups are composed of exclusively Portuguese varieties; Rabiça, Pérola Amarela (V66) and Pera de Inverno formed another group of their own; the reference cultivars Passe Crassane, Conference, Doyenné du Comice and William's grouped together with Formiga, Pérola Branca, Marquesinha, Pigarça, Fim de Século, Tipo Cabaça, Marmela, Rugosa and Nacional; the reference Abée Fetel grouped with Bojarda and an unnamed variety; Baguim, S. Bento de Chaves and the Pyrus pyrifolia Nashi are isolated from each other and form the remaining three classes. Our results indicate that both farmer selection of seedlings of older varieties and introgression in local genotypes of French and English varieties introduced in the 19th century played an important role in the formation of the present genetic variability found in pear genetic resources. These SSRs study is a good contribution to improve the pear germplasm management and can also be useful in the definition of a preservation strategy concerning the Portuguese pear landraces.
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