Genetic diversity and similarity of pear (Pyrus communis L.) cultivars in Central Europe revealed by SSR markers

Abstract

The Hungarian pear gene bank, located and founded in Keszthely in 1981, contains 210 pear cultivars including regional cultivars, cultivars of foreign origin and standard commercial cultivars. There are some cultivars with synonym names in the pear gene bank and in other pear growing areas within the Hungary. The aim of our work was to systematically analyse the genotypes of Hungarian cultivars in the pear gene bank and to set up a robust protocol for molecular identification and the interpretation of data. Eighty-eight cultivars were analysed employing eight SSR primers resulting in a total of 216 alleles. Seventy-seven cultivars were thoroughly analysed. Among the samples 29 were considered to be diploids and 59 triploids. A genetic diversity analysis was computed based on a Neighbour-Joining algorithm and combined with a PCA indicating close genetic relationship and an overall high amount of genetic diversity among the samples tested. Similarities and very close relations were verified in our studies between different pear cultivar variants: 'Korai szagos' A and B, which were planted with the same name in the gene bank. Six different 'Császár körte' and three 'Köcsög körte' cultivars were compared. It was important to establish how close their relationship was. Some cultivars originating from the same regions were compared. The 'Mez} okövesdi 2 0 and '3 0 are in the same main branch, however their distance is larger, the number of common alleles is less than those of the two 'Erdélyi körte' cultivars.

Autochthonous Austrian Varieties of Prunus avium L. Represent a Regional Gene Pool, Assessed Using SSR and AFLP Markers

“…The optimized multiplex-PCR approach to SSR genotyping was broadly successful; 11 of the 12 SSR-markers were easily scored and standardized against published data for five reference accessions (data not shown). This gives us confidence in the quality of the data generated which should prove straightforward to compare with similarly standardized data for other germplasm collections in the future The number of markers was comparable to that of similar studies [3,4,23,27,51] and showed to be sufficient to reveal the genetic diversity of MLGs expected to be present in the samples analyzed. Furthermore, with an average of 6.3 alleles per locus and PIC-value of 0.59 as well as the above-average expected and observed heterozygosity-levels, it is clear that the set of SSR-markers chosen was highly informative in the sweet cherry varieties in this study.…”

“…Autochthonous varieties and their wild relatives are valuable genetic resources for the breeding and development of any domesticated crop [1][2][3][4]. Global climate change is a key driver for some of the challenges that sweet cherry production must address, such as double fruits [5] or fruit cracking [6] stem.…”

“…(2) Can Austrian sweet cherry landraces be successfully differentiated by the selected set of SSR markers? (3) Have the selected accessions and landraces been correctly identified?…”

Genetic Diversity and Structure of Local Pear Cultivars from Mountainous Areas from Aragon (Northeastern Spain)

“…The benefit and need of the genetic identification of pear germplasm banks, improving the management of collections by enabling the identification of duplicates, synonyms, and homonyms, as well as to understand the origins of local varieties, and to ascertain the importance of introgression, polyploidy, and hybridization in their evolution have been widely reported [15,28,30,31,33]. In the last decades, several regional germplasm collections have been promoted in order to face the erosion caused by the introduction of improved varieties in specialized orchards, maintain and preserve the autochthonous diversity.…”

“…Single Sequence Repeats Markers have also been used for this matter [24,25] and have been proven to be a smart choice option because of their transferability, synteny and great conservation [26], as well as their codominance, high polymorphism and ease of application [27], which facilitates result interpretation and ensure reproducibility. In pear, several works have been carried out in different countries to study genetic variability in pear, including modern cultivars and germplasm accessions using SSR markers, such as in Spain [13][14][15]28], Italy [29], Hungary [30], Sweden [31], Bosnia and Herzegovina [32] and Portugal [33,34]. However, there are few studies regarding the genetic diversity in fruit trees located in mountain areas [35][36][37].…”