The utilization of unreplicated trials for conservation and quantification of intravarietal genetic diversity of rarely grown ancient grapevine varieties

Abstract

The conservation of the genetic diversity within ancient grapevine varieties, which are rarely grown nowadays and are subject to genetic erosion, is extremely important in guaranteeing future utilization. This article studies the use of unreplicated trials as a way of preserving the genetic variability of those varieties and quantifying their intravarietal diversity as the raw material for future selections. Through simulation, several experimental situations were generated, varying the numbers of test and check treatments and the type of experimental design associated with the check treatments (augmented randomized complete block design and alpha–alpha design). The quality of the estimates of genotypic variance increased with the increase of the number of genotypes in the conservation collection and with the frequencies of plots with check genotypes. A greater precision was achieved in the quantification of the genetic diversity of ancient grapevine varieties when collections of over 250 genotypes and a minimum of 33 % of plots containing check genotypes were used.