Main content area

Ex situ conservation and characterization of the genetic diversity of Castanea spp.

Mellano, M. G., Torello-Marinoni, D., Boccacci, P., Donno, D., Cerutti, A. K., Beccaro, G. L.
Acta horticulturae 2018 no.1220 pp. 1-6
Castanea sativa, Cynipidae, Quercus petraea, animal nutrition, arboreta, blight, coevolution, cultivars, ecotypes, ex situ conservation, flour, flowers, genetic variation, germplasm, human population, leaves, loci, microsatellite repeats, nuts, phenology, risk, species diversity, timber production
Co-evolution between Castanea spp. biodiversity and human populations has resulted in a wide genetic biodiversity in the world. The high pedoclimatic adaptability and the wide genetic variability of the species determined the spread of many different ecotypes and cultivars in the wild. These different genotypes were vegetative propagated by grafting, for many applications as fresh consumption, flour and timber production, animal nutrition, contributing to the conservation of the natural species biodiversity. Currently Castanea spp. is critically endangered and hundreds of genotypes are at risk of being lost due to a high number of phytosanitary problems (canker blight, ink disease, gall wasp). The aim of the research was to collect, identify, describe, and ex situ preserve the germplasm of Castanea spp. in order to provide additional strategies to complement current efforts to protect the species. Leaves, flowers, and nuts of analyzed cultivars were sampled in situ and ex situ in the collection field. Through direct observation, or published information, when available, phenological and morphological traits were used to characterize the genotypes. Moreover, the accessions were genetically characterized by multiplex analysis of seven microsatellite loci isolated in Castanea sativa and Quercus petraea. The results obtained in the set of accessions showed that microsatellite loci identified considerable polymorphism and confirmed that these markers are suitable for fingerprinting chestnut cultivars: the combined profiles across the 7 SSR loci showed the presence of a total of 105 different genotypes. In the past, the high horticultural value of many Castanea spp. genotypes allowed the biodiversity of the species to be maintained by the human populations, while today their genetic variability is critically endangered: the creation of the arboretum and similar initiatives, as genotype characterization and conservation, carried out by other international Institutes, could represent the first step in stopping the loss of biodiversity.