PROSPECTS OF USING DNA-MARKERS IN GRAPEVINE BREEDING

DNA-markers are actively used for the fin-gerprinting of genotypes, identification of va-rieties, in phylogenetic studies, for assessing genetic diversity, for mapping genes, etc. The article presents an analytical review of the achievements in the use of molecular markers in grape genetics as a basis for breeding works. Information is given about mapped genes and quantitative traits loci of grapes (QTL), about identified DNA-markers. It is shown that, using DNA-markers, was imple-mented the identification of genetic determi-nants determining such traits as resistance to pathogens (Agrobacterium sp. Plasmopara viticola, Erysiphe necator, Guignardia bidwellii, etc.), as well as grape quality indica-tors (berry pulp structure, berry size, seedless-ness, etc).Also, sets of DNA-markers have been developed for many of the identified genes. DNA-markers are used to identify genes of valuable traits in hybrid populations and to select the parental forms - gene donors. The DNA-marking method is used in the breeding to accelerate the transfer of econom-ically valuable genes and create new varieties with the required traits. The progress of mo-lecular genetic research in recent decades opens up new opportunities for grape breed-ing. The expediency of using DNA-markers and their selection for research should be as-sessed precisely for a specific breeding pro-gram.

The Behaviour of Some Grapevine Varieties to the Guignardia bidwellii Fungus Attack

Guignardia bidwellii or black rot of vine is one of the most dangerous diseases that occur in vineyards in the center of Transylvania. The objective of this work was the tolerance testing of varieties and clones homologated at SCDVV Blaj to the Guignardia bidwellii attack. The behavior of vine varieties to the Guignardia bidwellii fungus attack was characterized by the analysis of the severity of the symptoms according to a scale in function of the attack degree (AD). The results obtained revealed the tolerance of the tested varieties: ‘Rubin’ (AD=0.13%), ‘Amurg’ (AD=0.25%), ‘Brumariu’ (AD=0.78%), ‘Radames’ (AD=0.96%) and ‘Blasius’ (AD=0.97%), a medium tolerance presented ‘Selena’ (AD=9.28%) variety and ‘Neuburger-10 Bl’ (AD=5.04%), ‘Iordana 9-1 Bl’ (AD=6.40%), ‘Riesling de Rhin 7-2’ (AD=7.2%), ‘Sauvignon-9 Bl’ (AD=9.28%), ‘Traminer roz-60 B’ clones (AD=17.5%) and susceptibility for ‘Astra’ variety (AD=25.56%) and ‘Riesling italian-3 Bl’ (AD=22.4%), ‘Pinot gris-34 Bl’ (AD=30.60%), ‘Feteasca regala-21 Bl’ (AD=31.50%), ‘Muscat Ottonel-12Bl’ (AD=35.30%), ‘Feteasca alba-29 Bl’ clones (AD=38.40%). The results obtained regarding the behavior of grapevine in the climatic conditions specific to the studied area for the 2016-2018 period, show that the lowest values of AD were registered for the ‘Rubin’ (AD=0.13%), ‘Amurg’ (AD=0.25%), ‘Brumariu’ (AD=0.78%), ‘Radames’ (AD=0.96%) and ‘Blasius’ (AD=0.97%) varieties homologated at SCDVV Blaj.

Detección por PCR de Guignardia bidwellii, agente causal de la pudrición negra de la vid

<em>Guignardia bidwellii</em> (anamorfo: <em>Phyllosticta</em> <em>ampelicida</em>) es el agente etiológico de la pudrición negra de la vid, enfermedad de importancia económica en Europa y cuarentenaria para México. La identificación del estado anamorfo mediante caracteres morfológicos resulta complicada debido a la similitud entre especies del mismo género, por ejemplo, con el endófito cosmopolita <em>G. endophyllicola</em> (<em>P. capitalensis</em>), por lo que es necesario contar con herramientas de diagnóstico rápidas y específicas. Con este propósito se desarrolló un marcador molecular basado en los polimorfismos de un solo nucleótido (SNP) en la región ITS del ADNr, donde se diseñaron los oligos Bidwell y Ampel2 que mediante amplificación PCR generan un fragmento de 173 pb específico a <em>G. bidwellii f. euvitis</em>. La validación del método demostró que no hay amplificación cruzada con otros hongos fitopatógenos ni con el genoma de la vid. La técnica fue sensible al detectar hasta 30 pg µL-1 de ADN a partir de cultivos monospóricos y en mezcla con tejido vegetal. Se presenta este procedimiento de diagnóstico como una opción rápida y específica para el monitoreo y detección de <em>G. bidwellii f. euvitis</em> en apoyo a las estrategias de prevención, manejo, cuarentena y erradicación de la enfermedad.

Production of Pycnidia and Conidia by Guignardia bidwellii, the Causal Agent of Grape Black Rot, as Affected by Temperature and Humidity

Black rot, caused by the fungus Guignardia bidwellii, is a polycyclic disease affecting grape leaves and berries. In environmentally controlled experiments and in a 3-year field study, the effects of temperature and relative humidity (RH) were assessed on the following growth parameters of G. bidwellii: (i) formation of pycnidia and cirri in grape leaf lesions, (ii) production and germination of conidia, and (iii) length of the period between lesion appearance and pycnidia production. Pycnidia were produced between 5 and 35°C and at 90 to 100% RH but more pycnidia were produced between 20 and 30°C. No pycnidia were produced at RH < 90%. The first pycnidia were produced in approximately 2 days after lesion appearance at ≥20°C and in 8 days at 5°C; pycnidia continued to be produced on the same lesion for 5 to 16 days after lesion appearance, depending on the temperature. Models were developed to describe the effect of temperature and RH on pycnidia production, accounting for 95 and 97% of variability, respectively. Cirri were extruded only between 15 and 35°C and mainly at 100% RH. Field experiments confirmed that pycnidia are produced for several days on a leaf lesion and that the length of the period between lesion appearance and pycnidia production depends on temperature. Overall, the findings showed that production of conidia requires high humidity; under field conditions, some hours at high humidity, which usually occur at nighttime, rather than constant high humidity may be sufficient.

Feketerothadás, az új kihívás a szőlő rezisztencia nemesítésében

A feketerothadás a peronoszpóra és a lisztharmat mellett az egyik legveszélyesebb betegsége a világszerte termesztett szőlőnek, a Vitis vinifera-nsk. A megbetegedést a Guignardia bidwellii (Ellis) Viala & Ravaz) észak-amerikai eredetű gomba okozza. A kórokozó a 2000-es évek óta jelent súlyosabb problémát Európa számos borrégiójában a vegyszerhasználat mérséklését célzó törekvések miatt. Hazánkban 2010 óta rendszeresen megfigyelhető kártétele. A növényvédelemben a feketerothadás új kihívást jelent, mert a gomba fertőzésének kedvező meleg, csapadékos években akár a termésveszteség 100%-os is lehet. A Pécsi SZBKI szőlőnemesítési programjának célja a feketerothadás ellenállóság beépítése az innovatív lisztharmat és peronoszpóra rezisztens fajtajelöltekbe. Ezáltal megvalósíthatóvá válna a kiváló minőséget eredményező, permetezés nélküli szőlőtermesztés. Jelen tanulmány célja erről az új kórokozóról szerzett ismeretek, valamint a feketerothadás rezisztencia nemesítéséhez szükséges források kiválasztásának bemutatása. Eddigi vizsgálataink során újabb feketerothadás rezisztencia forrást emeltünk ki a nemesítési programunk számára, a 'Csillám' és a 'Seyval blanc' (Seyve-Villard 5276) fajtákat.

Crop wild relatives as genetic resources – the case of the European wild grape

Schröder, S., Kortekamp, A., Heene, E., Daumann, J., Valea, I. and Nick, P. 2015. Crop wild relatives as genetic resources – the case of the European wild grape. Can. J. Plant Sci. 95: 905–912. Vitis vinifera L. ssp. sylvestris (Gmelin) Hegi, the European Wild Grape and ancestor of cultivated grapevine varieties (V. vinifera L. ssp. vinifera) is the sole wild grapevine species existing in Europe. This important crop wild relative (CWR) species is almost extinct, and persists only in residual habitats. Since these habitats are close to vineyards, this CWR species is endangered by hybridisation with its descendant crop and naturalised rootstocks that originate from viticulture. For this reason, we addressed two questions: To what extent have the remaining South German European Wild Grape accessions escaped hybridisation and preserved genetic identity? Second, what is the potential of this CWR species as a genetic resource for breeding in relation to several grapevine diseases? Using a set of highly resolving genetic markers, we were able to exclude introgression of autochthonous sylvestris accessions by cultivated grapevine. However, we detected introgression mostly from wild American species used as rootstocks in viticulture. The autochthonous accessions can be grouped into clusters. Comparative inoculation studies with the grapevine pathogens powdery mildew (Erysiphe necator), downy mildew (Plasmopara viticola), and black rot (Guignardia bidwellii) revealed relatively high levels of resistance in some of the ssp. sylvestris accessions and represents a valuable genetic resource for resistance breeding.