Genetic and morphological characterization of chestnut (Castanea sativa Mill.) germplasm in Piedmont (north-western Italy)

Abstract

Castanea sativa Mill. is an important multipurpose tree species for north-western Italy, and specially for Piedmont Region. The preservation of its germplasm from the genetic erosion due to the changes in socio-economic structure of rural areas and specific pathogen attacks is critical. The principal aims of this work were to characterize the chestnut germplasm grown in Piedmont and investigate its genetic structure. Sixty-eight grafted chestnut trees were evaluated using 10 SSRs (simple sequence repeats) loci and 20 morphological descriptors.Thirty-six different genotypes were identified; the analysis of the genetic structure of this germplasm revealed that four gene pools contributed to the formation of the population sampled . In general, cultivars tended to group into a main gene pool on the basis of their prevalent use and growing area. These results are substantially in agreement with those of the cluster analysis that was carried out to estimate the genetic relationships among the cultivars.Morphological analyses showed large variation of traits among the individuals, related with the market destination of the nuts and useful for cultivar and clonal selection. Discriminant analysis was applied to find a correlation between genetic and morphological data: nut and leaf shape, nut hairness and male flower type resulted to be the most discriminant traits associated with the genetic structure.In the end, this work clarified the genetic structure of the cultivated germplasm in Piedmont describing the main cultivars of the Region, giving useful information for conservation and breeding purposes.

Castanea spp. buds as a phytochemical source for herbal preparations: botanical fingerprint for nutraceutical identification and functional food standardisation

“…and human populations have resulted in the spread of a rich and varied genetic diversity of chestnut throughout most of the world, especially in mountainous and forested regions. Its plasticity and adaptability to different pedoclimates and the wide genetic variability of the species determined the spread of many different ecotypes and varieties in the wild …”

Identification of traditional Galician sweet chestnut varieties using ethnographic and nuclear microsatellite data

“…Although microsatellite genotypes of most of the important Galician varieties analyzed in this study have been previously reported by other authors(Pereira-Lorenzo et al 2011), some major varieties such as Negral, Loura, De Presa, and Luguesa and various secondary varieties have not been previously genotyped using SSRs.Comparisons of the values of observed heterozygosis and fixation index obtained in this study with those obtained in other European areas can be made in spite of assayed microsatellites are different; all authors used between 7 and 10 SSRs. The ranking of Ho values in different zones is as follows: Piedmont Ho=0.755>Galicia Ho=0.716>Andalucía Ho=0.727>Emilian Apennines Ho=0.66>El Bierzo (Spain)=0.61>all Iberian Peninsula Ho=0.609(Marinoni et al 2013; Fernández-López and Fernández-Cruz, this document;Martín et al 2009;Berghè et al 2013;Quintana et al 2015; Pereira et al 2011, respectively). The excess of heterozygotes that was detected in this Galician study (F=−0.105) is higher than heterozygosis in varieties of other zones: Emilian Apenin (F=−0.096;Berghè et al 2013); in varieties of Andalucian sweet chestnut orchards (F=−0.058;Martín et al 2009); in Piedmont (F=−0.028;Marinoni et al 2013); in El Bierzo (F=−0.016;Quintana et al 2015); and South Switzerland (F=−0.007;Gobbin et al 2007).…”

“…The ranking of Ho values in different zones is as follows: Piedmont Ho=0.755>Galicia Ho=0.716>Andalucía Ho=0.727>Emilian Apennines Ho=0.66>El Bierzo (Spain)=0.61>all Iberian Peninsula Ho=0.609(Marinoni et al 2013; Fernández-López and Fernández-Cruz, this document;Martín et al 2009;Berghè et al 2013;Quintana et al 2015; Pereira et al 2011, respectively). The excess of heterozygotes that was detected in this Galician study (F=−0.105) is higher than heterozygosis in varieties of other zones: Emilian Apenin (F=−0.096;Berghè et al 2013); in varieties of Andalucian sweet chestnut orchards (F=−0.058;Martín et al 2009); in Piedmont (F=−0.028;Marinoni et al 2013); in El Bierzo (F=−0.016;Quintana et al 2015); and South Switzerland (F=−0.007;Gobbin et al 2007). …”

“…Several SSR-based Fig. 1 Sweet chestnut distribution in Galicia and Spain and zones of varieties (Ia, Ib, IIa, IIb, IIc, III, and IV) identified in Galician orchards using local variety names; dots indicate the place where accessions were sampled studies of chestnut varieties from Switzerland (Gobbin et al 2007), Italy (Berghè et al 2013;Marinoni et al 2013), and Spain (Martín et al 2009;Pereira-Lorenzo et al 2011;Quintana et al 2015) have been reported in recent years.…”

Genetic diversity of Castanea sativa an endangered species in the Hyrcanian forest

“…Fixation index estimates and AMOVA data are supportive of an unexpectedly high level of genetic differentiation in El Bierzo, larger than that estimated in a previous study with a broader geographical scope. Torello Marinoni et al (2013) revealed that four gene pools contributed to the formation of the population of C. sativa in northwest Italy. Mattioni et al (2013) studied on a largescale the genetic diversity of C. sativa by SSR and the results showed a genetic divergence between the eastern (Greek and Turkish) and western (Italian and Spanish) populations.…”