Concord grape (Vitis labrusca) plants were inoculated with Macroposthonia xenoplax at levels of 100, 1,000, and 10,000 nematodes. After 4 months, plants inoculated with 10,000 M. xenoplax were stunted, and root systems were darker and had fewer feeder roots than those in other treatments. The lower nematode inoculation levels suppressed top growth but did not affect root growth. M. xenoplax rep...

Three Cryptosporiopsis species have thus far been isolated from roots of woody plants. A fourth species, which was recently isolated from roots of Calluna vulgaris, Erica tetralix, Vaccinium vitis-idaea, and V. myrtillus in The Netherlands, is described here as new. Sporulation on the natural substratum has not been observed and the morphological description of this fungus is therefore based on...

Xylella fastidiosa (Xf) is the causal agent of Pierce’s disease in grapevines. The mechanisms of pathogenicity are largely due to occlusion of xylem vessels by aggregation of Xf and biofilm formation. Our previous work has documented the effects of xylem constituents on both Xf proliferation and biofilm formation. This current research utilizes 1) addition of xylem constituents to defined media...

zinnia elegans, an annual flowering plant of the genus zinnia, is one of the best known zinnias. present study was conducted to evaluate the effect of different growing media on the growth and flowering of zinnia elegans. seven different growth media including coconut compost, silt, soil loam, leaf manure, (leaf manure + silt; 2:1), (coconut compost + soil loam; 1:1) and (leaf manure + soil loa...

The leafhopper Scaphoideus titanus is the vector of 'Candidatus Phytoplasma vitis', the causal agent of Flavescence dorée (FD) a key disease for European viticulture. In organic vineyards, the control of S. titanus relies mostly on the use of pyrethrins that have suboptimal efficacy. During 2016, three field trials were conducted to evaluate the efficacy of kaolin, orange oil, insecticidal soap...

Vitis vinifera, known as the grapevine, is native to southern Europe and Western Asia. Grape seed and skin contain several active components including flavonoids, polyphenols, anthocyanins, proanthocyanidins, procyanidines, and the stilbene derivative resveratrol. Grape seed extract in particular has been reported to possess a broad spectrum of pharmacological and therapeutic effects such as an...

Morphological, anatomical and physiological features of in vitro plantlets are affected by the environmental conditions experienced. The high water content inside in vitro-formed tissues makes difficult to maintain the original characteristics of samples from in vitro plantlets during the preparation procedures for morphological and anatomical studies. In this paper, micropropagated Vitis vinif...

The vascular system of grapevine (Vitis spp.) has been reported as being highly vulnerable, even though grapevine regularly experiences seasonal drought. Consequently, stomata would remain open below water potentials that would generate a high loss of stem hydraulic conductivity via xylem embolism. This situation would necessitate daily cycles of embolism repair to restore hydraulic function. H...

Understanding relationships among species is a fundamental goal of evolutionary biology. Single nucleotide polymorphisms (SNPs) identified through next generation sequencing and related technologies enable phylogeny reconstruction by providing unprecedented numbers of characters for analysis. One approach to SNP-based phylogeny reconstruction is to identify SNPs in a subset of individuals, and ...

Vacuolar processing enzymes (VPEs) have received considerable attention due to their caspase-1-like activity and ability to regulate programmed cell death (PCD), which plays an essential role in the development of stenospermocarpic seedless grapes ovules. To characterize VPEs and the relationship between stenospermocarpic grapes and the VPE gene family, we identified 3 Vitis vinifera VPE genes ...