Exploring variability and the putative influence of rootstocks in fruit from ‘Muscat of Alexandria’ clones selected at La Marina Alta (Spain), growing under rain-fed conditions

Summary Background of the study – An increment in drought and negative changes of grapevine quality are being associated to climate change. Selecting clones and rootstock-scion combinations can help to cope with these matters. Objectives – To explore the variability for bunch and berry characteristics, as well as the putative influence of rootstock in these traits in three ‘Muscat of Alexandria’ clones selected at La Marina Alta (Alicante, Spain). Methods – Intravarietal variability was studied by ampelographic and eno-carpological descriptors and chemical analysis in plants of ‘Muscat of Alexandria’ CM11, CM14, and CM16 clones grafted onto 110R, 1103P, and 41B rootstocks and cultured under rain-fed conditions. Results – Variability among clones and influence of rootstock in parameters affecting wine quality are found, all of them showing good acidity in rain-fed growing conditions. Differences for ampelographic and eno-carpological descriptors in bunches and berries are also noted, highlighting the elongated berries and late ripening of the clone CM14. Conclusions – The intra-variability found for visual and/or quality traits as well as the acquired knowledge of the rootstock influence in these parameters is of interest for this globally distributed grape variety, used for winemaking and as a table grape; especially in the current scenario of climate change.