Investigating variability of the cultivar ‘Pinot blanc’ under different aspects

Abstract

Several certified 'Pinot blanc' clones available at a local market were evaluated under specific viticultural conditions. Small but relevant differences in agronomic behaviour could be recognized. Clones A9-1, Fr74, H31 and N81 showed higher yield, while clones Lb16 and 18, Fr70 and 74 and N81 reached higher berry sugar contents. Clone Fr74 showed the most vigorous growth. Clones Fr70 and Dreher209 produced wines with the highest quality ratings. Analysis of essential aroma compounds by HS-SPME-GC-SIM-MS reveals that the clone Dreher209 is characterized by high values of terpenes and floral aroma. Pear-specific odour activity values (OAVpear) presented as sensorial-analytical typograms were calculated from the analysed concentrations of eight esters in clones. The overall OAVpear of the wines ranged from 37.5 (H31, 2016) to 84.3 (N81, 2017). The largest contributors to the pear OAV were the impressions for “exotic pear candy” and “oily waxy pear-like”. The sum of OAV “fresh pear” and “overripe pear” ranged from 6.9 (H31, 2016) to 16.1 (N81, 2017). However, an influence of vintage on the sensorial descriptors “overripe pear” and “OAV pear” was determined. A positive correlation between sugar content °Babo KMW and the descriptors for “fresh pear” and “overripe pear” is likely. Thus, clone H31 showed the lowest sugar content and lowest OAV fresh pear and OAV overripe pear content. The genetic variability was estimated by applying fingerprints with simple sequence repeat (SSR), inter-SSR and single-nucleotide polymorphism (SNP) markers. The certified clones are characterized by less variability compared with some other candidate genotypes involved in this study. No stable differences could be found in A9-1, A9-3, A9-4, C311, Fr70, or N81. That means that the clones investigated do not cover the broader genetic base of the cultivar, and that some of these clones are almost identical.