Vitis: Journal of Grapevine Research 

About: Vitis: Journal of Grapevine Research is an academic journal. The journal publishes majorly in the area(s): Wine & Rootstock. It has an ISSN identifier of 0042-7500. Over the lifetime, 1754 publications have been published receiving 23841 citations.

Influence of water deficits on grape berry growth

Abstract: The effects of early and late water deficits on pericarp cell division and enlargement of Syrah berries ( Vitis vinifera L.) was determined by DNA extraction and quantification. Different periods and different levels of water deficit were applied between anthesis and maturity to grapevines growing under controlled water supply in two consecutive years. DNA extraction profiles showed that water deficit did not affect cell division. Reduction of berry size and berry weight was caused exclusively by a decrease of pericarp volume, independent of the intensity of the water deficit or the stage of berry development. Decreased cell volume as a result of an early water deficit from flowering to veraison was irreversible. These results support the hypothesis that early water deficits modify the structural properties of the cell components and consequently cell wall extensibility, thereby limiting the subsequent enlargement of pericarp cells.

Molecular characterisation of grapevine yellows associated phytoplasmas of the stolbur-group based on RFLP-analysis of non-ribosomal DNA

Abstract: Grapevines, alternative host plants, and vectors from different viticultural areas of Germany were surveyed for the presence of stolbur-group phytoplasmas that are associated with grapevine yellows. Isolates from these field samples and periwinkle isolates of stolbur were characterised by RFLP-analysis of non-ribosomal DNA fragments using a combination of 6 polymorphic primer-enzyme combinations. Three of the 5 different restriction profiles that could be distinguished were found in grapevine and other field samples of plants and insects. A previously unknown isolate was detected in grapevine, vectors and the newly identified herbaceous host Calystegia sepium . The further analysis of the phylogenetic relationship between the 5 RFLP groups revealed a close relationship between two of the isolates associated with grapevine yellows which were also found in the two Convolvulaceae Convolvulus arvensis and Calystegia sepium . The third isolate which was detected in grapevine and stinging nettle Urtica dioica is more closely related to a periwinkle isolate obtained from Lavandula officinalis than to the other two grapevine yellows isolates. Based on the data of the field survey a specific association of the three isolates to different alternative host plants is discussed.

Flavescence doree in France and Italy - Occurrence of closely related phytoplasma isolates and their near relationships to Palatinate grapevine yellows and an alder yellows phytoplasma

Abstract: Grapevine yellows (GY) are diseases of Vitis vinifera caused by phytoplasmas. On the basis of DNA analysis, it is possible to distinguish different groups and subgroups among grapevine phytoplasmas. Flavescence doree (FD), the most serious problem in European vineyards, is caused by a phytoplasma which belongs to the elm yellows group (EY or 16SrV), Differences between 7 phytoplasma isolates in this group, found until now in French, Italian and German grapevines, and 4 phytoplasmas in the same group, isolated mainly from elm and alder in Europe and America, were investigated. These 11 EY-group isolates plus 3 non-EY phytoplasmas, were compared by PCR-RFLP analyses of two different DNA fragments using 8 restriction enzymes. Two French and two Italian grapevine isolates, classified as FD, appeared to be closely related and were also closer to an Italian alder phytoplasma. One French and one Italian FD isolate always showed the same restriction pattern. On the opposite, the three German grapevine isolates related to alder phytoplasmas in Germany appeared to be closer to the two elm phytoplasmas from America and Europe.

Phenologic and growth responses to early and late season water deficits in Cabernet franc

Abstract: Phenologic and ontogenic responses to seasonal water deficits were investigated in the wine grape variety, Cabernet franc, in a California hillside vineyard. Water deficits were imposed by withholding irrigation water before or after the onset of veraison. In continually irrigated vines, midday leaf water potential (Ψ) declined from - 0.4 MPa to approximately -1.1 MPa between budbreak and veraison despite weekly irrigation at a rate which was 2 x the normal production practice for that commercial vineyard. Hence, water deficits may be a common component of grape production in hillside vineyards of California. When water was withheld until veraison, midday Ψ declined more rapidly and reached - 1.4 MPa at the time water was resupplied. For these vines, water status slowly recovered to the level of the continually irrigated vines. The water status of late deficit vines, (water withheld after veraison), decreased rapidly after veraison, reaching a minimum of - 1.6 MPa at harvest. These differences in vine water status had no effect on the major phenological indicators, i. e„ the timing (on basis of time or accumulation of degree days) of bloom, veraison, and harvest. However, early season deficits shortened the period of shoot elongation and node production, decreased the maximum rate of shoot elongation and node production, and accelerated periderm development on current season shoots. Possible ecological implications of accelerated periderm development are discussed. Shoot length and the number of nodes/shoot was reduced approximately 25 % by the early season water deficits. Radial shoot growth was also inhibited by early deficits but much less than axial shoot growth. Shoot growth had essentially ceased in all vines before late season deficits developed. The characteristic double-sigmoid growth pattern of berries was observed regardless of seasonal water deficits. Most fruit growth occurred during the first growth phase in all treatments. The rate of fruit growth was inhibited by early and late season water deficits. Yield was decreased more by early deficits than by late deficits.