scholarly journals Evaluation of Different Grape Varieties for Resistance to Powdery Mildew Caused by Uncinula Necator

2009 ◽  
Vol 49 (4) ◽  
pp. 434-439 ◽  
Author(s):  
H. Khiavi ◽  
Haji Shikhlinski ◽  
A. Ahari ◽  
Asgar Heydari

Evaluation of Different Grape Varieties for Resistance to Powdery Mildew Caused byUncinula NecatorPowdery mildew is one of the most serious and destructive diseases of grapes around the world including Iran. Although the application of chemical pesticides is the most common control method, the use of resistant varieties may be the most effective and environmentally sound strategy for managing the disease. Fourteen grape varieties were evaluated for testing powdery mildew (Uncinula necator) resistance under natural infection conditions and artificial inoculation methods were used during 2007-2008 in Ardabil province of Iran. Disease severity on leaves and fruit (cluster) were evaluated using Voytovich (1987) procedure. Results of the experiments showed that Shahani, Yagothi and Tabrizkishmishi cultivars were immune, Sahibi cultivar was highly resistant, Agshilig and Tokoulgan were resistant, Kishmishi, Khalili and Tabarzeh cultivars were tolerant, Aldarag and Koupakbogan were susceptible and Garashilig, Seyrakpousteh and Rasmi cultivars were highly susceptible to the disease. In general, results of this study were promising and some immune, highly resistant and resistant cultivars toU. necatorwere identified and they may be used as a resistance genetic source for management of the disease in national and international programs.

2021 ◽  
Vol 39 ◽  
pp. 02005
Author(s):  
Marina Makarkina ◽  
Elena Ilnitskaya ◽  
Tatiana Kozina

Powdery mildew (Erysiphe necator) is one of the most common and economically significant diseases of grapes. Currently, the main method of controlling the disease is pesticide treatment. Breeding of resistant varieties is necessary to reduce chemical treatments. Currently, a number of grape resistance genes to powdery mildew and DNA markers for identification the allelic status of these genes are known. In a study to determine the presence of resistance loci Ren3 and Ren9, 25 genotypes of table grape varieties were analyzed, including 18 seedless varieties. DNA markers GF15-42, ScORGF15-02 were used to identify Ren3 gene, and CenGen6 – to identify Ren9 gene. DNA of cultivars Regent and Seyve Villard 12-375, which have resistance alleles, were used as positive controls. As a result of DNA marker analysis, it was determined that genotypes of table varieties Viking, Kodryanka, Moldova, Nadezhda AZOS, Original and seedless varieties Pamyati Smirnova, Kishmish Zaporozhskiy and Kishmish 342 carry loci of resistance to powdery mildew Ren3 and Ren9.


2015 ◽  
Vol 5 (1) ◽  
pp. 585-590
Author(s):  
Andekelile Mwamahonje ◽  
Deusdedit Kilambo ◽  
Leon Mrosso ◽  
Tileye Feyissa

This study was conducted to evaluate the susceptibility of grapevine varieties to powdery mildew. Powdery mildew is a disease caused by a fungal, Erysiphenecator, and an obligate parasite of grapevine (Vitisvinifera L.). Powdery mildew causes drastic yield losses of 50 to 70%. Commercial grapevines grown in producing countries are susceptible to powdery mildew. Use of fungicides to control the disease is expensive and not environmentally friendly. Therefore, use of grapevine resistant varieties to powdery mildew is cost-effective control method. In this study, ten varieties (Black rose, Regina, Queen of Vineyards, Alphoncelavallee, Makutupora red, Chancellor, Halilibelyji, Syrah, Ruby seedless and Makutupora white) were screened for resistance to powdery mildew, using artificial inoculation of spore suspension and dry inoculums. Infected grape leaves were sampled from the field and grounded to obtain powder which was used as dry inoculum. The spore suspension inoculum was made by mixing powder with sterilized distilled water. The inoculation was done in two blocks with concentration of 2x105 spore/ml. Disease severity was evaluated based on a scale of 0 5; 0, means immune and 5, high level of disease severity. Results showed significant difference (P<0.05) of disease among grape vine varieties evaluated. It was found that 11.1% were resistant, 33.4% tolerant and 55% susceptible to disease. Grapevine variety Chancellor showed the highest level of resistance, and Black rose the most susceptible. The study demonstrates the effectiveness of using inoculation methods in screening resistance to powdery mildew.


2009 ◽  
Vol 26 (Special Issue) ◽  
pp. S13-S17 ◽  
Author(s):  
P. Bábíková ◽  
N. Vrchotová ◽  
J. Tříska ◽  
M. Kyseláková

The aim of this project was to study changes in the content of <i>trans</i>-resveratrol in berries and leaves of grapevine (<i>Vitis</i> sp.) infested by fungal diseases, especially by <i>Botryotinia fuckeliana</i> Whetzel, called as grey mildew, <i>Plasmopara viticola</i> (Berk. & M.A. Curtis) Berl & De Toni, called downy mildew and <i>Uncinula necator</i> (Schw.) Burr, called powdery mildew. In our experiments two white and two blue varieties were used. Contents of <i>trans</i>-resveratrol were determined in healthy and infested leaves and in healthy berries. Infested leaves of white varieties contained more <i>trans</i>-resveratrol than those of blue varieties. The content of <i>trans</i>-resveratrol in berries was lower than that in leaves.


2010 ◽  
Vol 16 (2) ◽  
Author(s):  
Z. Mándoki

Newly bred resistant bell pepper varieties and those grafted onto resistant rootstock s were tested in soil severely infested with southern root-knot nematode [Meloidogy11e incognita (Kofoid and White) Chitwood] in unheated plastic house and compared to varieties on their own roots, in order to evaluate the efficiency of this environmentally friendly control method. 'Cinema F I ' carrying the N gene yielded significantly more than the two susceptible varieties. Varieties grafted onto resistant rootstocks outyielded those on their own roots although to different extent, which was not always significant. At the end of the vegetat ion period the roots of the rootstocks were undamaged and the roots of some resistant varieties were slightly infected. whereas the roots of susceptible varieties were severely damaged. According to our result  . both the use of resistant varieties and grafted plants offer an effective and environmentally safe way of controlling M. incognita.


Author(s):  
P. R. Ouyang ◽  
Truong Dam

For multi-axis motion control applications, contour tracking is one of the most common control problems encountered by industrial manipulators and robots. In this paper, a position domain PD control method is proposed for the purpose of improving the contour tracking performance. To develop the new control method, the multi-axis motion system is viewed as a master-slave motion system where the master motion is sampled equidistantly and used as an independent variable, while the slave motions are described as functions of the master motion according to the contour tracking requirements. The dynamic model of the multi-axis motion system is developed in the position domain based on the master motion by transforming the original system dynamic equations from the time domain to the position domain. In this control methodology, the master motion will yield zero tracking error for the position as it is used as reference, and only the slave motion tracking errors will affect the final contour tracking errors. The proposed position domain PD controller is successfully examined in a Cartesian robotic system for linear motion tracking and circular contour tracking.


2004 ◽  
Vol 94 (5) ◽  
pp. 438-445 ◽  
Author(s):  
Andrea Ficke ◽  
David M. Gadoury ◽  
Robert C. Seem ◽  
Dale Godfrey ◽  
Ian B. Dry

Grape berries are highly susceptible to powdery mildew 1 week after bloom but acquire ontogenic resistance 2 to 3 weeks later. We recently demonstrated that germinating conidia of the grape powdery mildew pathogen (Uncinula necator) cease development before penetration of the cuticle on older resistant berries. The mechanism that halts U. necator at that particular stage was not known. Several previous studies investigated potential host barriers or cell responses to powdery mildew in berries and leaves, but none included observation of the direct effect of these factors on pathogen development. We found that cuticle thickness increased with berry age, but that ingress by the pathogen halted before formation of a visible penetration pore. Cell wall thickness remained unchanged over the first 4 weeks after bloom, the time during which berries progressed from highly susceptible to nearly immune. Autofluorescent polyphenolic compounds accumulated at a higher frequency beneath appressoria on highly susceptible berries than on highly resistant berries; and oxidation of the above phenolics, indicated by cell discoloration, developed at a significantly higher frequency on susceptible berries. Beneath the first-formed appressoria of all germinated conidia, papillae occurred at a significantly higher frequency on 2- to 5-day-old berries than on 30- to 31-day-old fruit. The relatively few papillae observed on older berries were, in most cases (82.8 to 97.3%), found beneath appressoria of conidia that had failed to produce secondary hyphae. This contrasted with the more abundantly produced papillae on younger berries, where only 35.4 to 41.0% were located beneath appressoria of conidia that had failed to produce secondary hyphae. A pathogenesis-related gene (VvPR-1) was much more highly induced in susceptible berries than in resistant berries after inoculation with U. necator. In contrast, a germin-like protein (VvGLP3) was expressed within 16 h of inoculation in resistant, but not in susceptible berries. Our results suggest that several putative barriers to infection, i.e., cuticle and cell wall thickness, antimicrobial phenolics, and two previously described pathogenesis-related proteins, are not principal causes in halting pathogen ingress on ontogenically resistant berries, but rather that infection is halted by one or more of the following: (i) a preformed physical or biochemical barrier near the cuticle surface, or (ii) the rapid synthesis of an antifungal compound in older berries during the first few hours of the infection process.


2010 ◽  
Vol 41 (No. 3) ◽  
pp. 95-103 ◽  
Author(s):  
M. Ondřej ◽  
R. Dostálová ◽  
L. Odstrčilová

Cultivars, homozygous sources and lines of pea (<I>Pisum sativum</I> L.) resistant to <I>Erysiphe pisi</I> had recently been attacked by another powdery mildew species, <I>Erysiphe</I> <I>baeumleri,</I> in the field and in glasshouse conditions. Inoculation with <I>E. baeumleri</I> was carried out in the glasshouse to evaluate the level of resistance of 16 pea genotypes. Susceptible pea lines produced abundant conidia and cleistocarps on petioles and leaves. Only the genotype Tudor (Cebeco 4119) was found to be completely resistant to <I>E. baeumleri</I>. Nineteen pea genotypes (with gene <I>er-1</I>) were tested to natural infection by <I>E. baeumleri</I> in field screening trials. Only few of them demonstrated a high level of resistance (Fallon, AC Melfort and Joel). Consort R, SGL 2024, SGL 1977 and Franklin were very susceptible to <I>E. baeumleri</I>. Cleistocarps with 1–4× dichotomously branching apices of appendages were formed only on susceptible and very susceptible plants of genotypes SGL 444/2185, Consort R, SGL 2024, SGL 1977, LU 390-R2, Lifter, Highlight, Cebeco 1171 and Carneval R in the field and glasshouse. Susceptible control genotypes without gene <I>er-1</I> (Komet, Adept and Gotik) were attacked in the trials by <I>E.&nbsp;pisi</I> only.


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