Comparison of Heritage Zinfandel and Primitivo Selections in Napa Valley, California.

摘要

Seven selections of Zinfandel (Vitis vinifera L.) and one selection of genetically related Primitivo were compared for observable, phenotypical differences. The grapevine clonal selections were gathered from California heritage vineyards planted before 1919. The selections were all grafted onto St. George rootstock, and planted at the Oakville Experimental Station in a randomized complete block design (RCBD). The objective of this study was to determine whether there are any significant differences in fruit composition among these heritage clonal selections. We measured cluster weights, berry weights, berries per cluster, and seeds per berry to assess morphological differences of the grape cluster architecture. Juice composition was examined by measuring soluble sugars, pH, titratable acidity, yeast available nitrogen (YAN), and malic acid. Phenolic composition of the grape skins was separated using High Performance Liquid Chromatography and analyzed using a diode array detector (HPLC-DAD). Finally, pruning weights and timing of bud break were measured. Results demonstrate that most of the heritage selections included in this study did not express differences. However, lower cluster weights and fewer berries per cluster were observed in the Primitivo selection, and this may have a linkage to the higher degree of soluble solids and phenolic profile difference that was also observed.