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Most grapevine land races which were extensively grown in the last century in Oltrepò Pavese, Northern Italy, can today only be found in marginal old vineyards close to abandonment or eradication. Germplasm collected following an initial survey in 1986 was described during 1990-91 according to a basic list of morphological traits. Between 1990 and 1993, yield and must composition traits were measured for vines in the collection. In 1991, grapes from 15 representative Oltrepò land races were micro-vinified. Chemical and sensory analyses of wines were performed. Many local biotypes of each old cultivar were discovered in a second survey in Oltrepò carried out in 1990 and 1991, confirming that the most important land races described in the literature were not properly cultivars but rather variety populations, because of their large intra-population variability. To avoid genetic drift, it will therefore be necessary to reproduce this variability in germplasm collections. Anthocyanin high-pressure liquid chromatography profiles were successfully adopted to classify the land races into groups and for the purposes of variety identification. It was concluded that only a few of these land races may be proposed to growers as an alternative to traditionally grown cultivars, to increase the typicity of wines produced in the district.

Two trials, conducted in two locations in Italy over 4 years with Chardonnay grapevines trained to GDC, Pergola or Casarsa systems and grafted onto 6 rootstocks (SO4, Kober 5BB, Teleki 5C, 8B, 140Ru and 1103P), provided vine yield and pruning weight data to study a practical and reliable method for assessing genotypic stability. Commonly used stability statistics, like indices based on coefficients of variation and regression, were estimated. When the deviations from regression of genotype performances on the environmental index were large, biological response of rootstocks to different environments was better fitted by double regression analysis based on Verma's coefficients. The unpredictable part of the response in regression approach was quantified by Wricke's ecovalence index. The results confirmed that the use of more than one statistical procedure is necessary in the selection of stable genotypes. Genotype × environment interactions were partitioned into four components (variability, ecovalence, linear response or deviation from linear response, environmental sensitivity). The use of a graphical representation of the four components was easy to use and appropriate for grouping genotypes of greater and lesser stability. Rootstocks Teleki 5C and 8B were identified as stable for grape yield, while high yielding genotypes (SO4 and 1103 P) were judged as unstable. 140Ru and Kober 5BB were detected as stable for yield of pruning wood.