Loss of genetic diversity as a signature of apricot domestication and diffusion into the Mediterranean Basin

Abstract

BackgroundDomestication generally implies a loss of diversity in crop species relative to their wild ancestors because of genetic drift through bottleneck effects. Compared to native Mediterranean fruit species like olive and grape, the loss of genetic diversity is expected to be more substantial for fruit species introduced into Mediterranean areas such as apricot (Prunus armeniaca L.), which was probably primarily domesticated in China. By comparing genetic diversity among regional apricot gene pools in several Mediterranean areas, we investigated the loss of genetic diversity associated with apricot selection and diffusion into the Mediterranean Basin.ResultsAccording to the geographic origin of apricots and using Bayesian clustering of genotypes, Mediterranean apricot (207 genotypes) was structured into three main gene pools: ‘Irano-Caucasian’, ‘North Mediterranean Basin’ and ‘South Mediterranean Basin’. Among the 25 microsatellite markers used, only one displayed deviations from the frequencies expected under neutrality. Similar genetic diversity parameters were obtained within each of the three main clusters using both all SSR loci and only 24 SSR loci based on the assumption of neutrality. A significant loss of genetic diversity, as assessed by the allelic richness and private allelic richness, was revealed from the ‘Irano-Caucasian’ gene pool, considered as a secondary centre of diversification, to the northern and southwestern Mediterranean Basin. A substantial proportion of shared alleles was specifically detected when comparing gene pools from the ‘North Mediterranean Basin’ and ‘South Mediterranean Basin’ to the secondary centre of diversification.ConclusionsA marked domestication bottleneck was detected with microsatellite markers in the Mediterranean apricot material, depicting a global image of two diffusion routes from the ‘Irano-Caucasian’ gene pool: North Mediterranean and Southwest Mediterranean. This study generated genetic insight that will be useful for management of Mediterranean apricot germplasm as well as genetic selection programs related to adaptive traits.

New microsatellite loci for annatto (Bixa orellana), a source of natural dyes from Brazilian Amazonia

“…As a result, local inbreeding coefficients were high in all populations (Table 2). Similar results for cultivated accessions were reported by Dequigiovanni et al (2014) Higher levels of genetic diversity in wild than cultivated crops were also found in other crops, due to genetic bottleneck effects during domestication, such as in tepary beans (Phaseolus acutifolius) (Blair et al 2012, Gujaria-Verma et al 2016 (Bitocchi et al 2013), apricot (Prunus armeniaca) (Bourguiba et al 2012), and sunflower (Helianthus annuus) (Mandel et al 2011). However, this is not always the case, since in some crops, e.g., in carrot (Daucus carota subsp.…”

S-Genotype Profiles of Turkish Apricot Germplasm

“…One of the most important factors in apricot crop evolution was the emergence of self-compatibility, which has resulted in a serious loss of genetic diversity in Europe and the Mediterranean Basin (Pedryc et al, 2009;Bourguiba et al, 2012). In a previous study, Halasz et al (2010) detected an uneven distribution of the S C-allele in Turkish apricot cultivars: no self-compatible cultivar was found among 11 tested genotypes in the Eastern Region, while 7 out of 14 tested cultivars from the Western part of the country were self-compatible.…”

Evaluation of metabolite extraction protocols and determination ofphysiological response to drought stress via reporter metabolites in model plant Brachypodium distachyon

“…Based on the different response of ATP levels according to extraction method and validation of ATP measurements with spiking experiments, it can be concluded that there is no single protocol that fits all species or even genotypes, and we conclude that tailor-made protocols are needed in plant metabolomics studies. In response to drought stress, the response level differs among genotypes, highlighting the importance of natural variation in Brachypodium (Opanowicz et al, 2008;Bourguiba et al, 2012;Verelst et al, 2013). This study will provide a basis for the construction of high-coverage metabolome platforms, and potentially lead to more reliable metabolome studies in plants and help further metabolomics studies on drought stress response in order to improve agriculturally important crop species.…”