Heritability and correlation studies of certain quantitative traits in table grapes, Vitis spp.

Heritabilities and phenotypic correlations among 10 traits of the grapevine (Vitis vinifera x V. rotundifolia hybrid derivatives) were estimated from measurements obtained from 46 families, induding a total of more than 1000 offspring generated by crosses among 26 parents. Measurements on fruit characters were obtained over a period of 4 years, 1976-1979. (General vigor of the vines was measured in only 1 year, 1976). Prior to this analysis the data on fruit traits were statistically adjusted to mitigate the confounding effects of fluctuating annual dimates on estimates of genotypic value. The heritabilities were then estimated by regressing the average performance of each seedling on the average performance of its mid-parent. Heritabilities are 0.12, 0.55, 0.49, 0.75, 1.04, 0.34, 0.15 and 0.10 for duster weight, duster compactness, berry weight, skin texture, pulp texture, total soluble solids, acidity of juice and general vigor, respectively. The heritability estimate for crop weight in this population is practically 0(-0.08). The precision of these estimates is very high, except for that of general vigor. Thus, they should be reliable predictors of the rate of genetic gain attainable in such populations when seedlings are selected as parents on the basis of their own performance. The expected performance of the progeny of randomly mated parents, ranked in the upper 5 % of the progeny generation, were estimated. The implications of these genetic relationships on the effectiveness and efficiency of breeding programs and selection procedures in grapes are discussed

The heritability of resistance to root-knot nematode (Meloidogyne incognita acrita CHIT.) in Vitis vinifera x V. rotundifolia hybrid derivatives

A population of 807 offspring of 46 families, generated by crosses among 26 parents (some quasi-F1 hybrids of V. vinifera x V. rotundifolia), the parents, 12 V. vinifera x V. rotundifolia (VR) hybrids, Muscat of Alexandria and Dog Ridge (controls) were all grown in the vineyard of the University of California at Davis and were tested in a greenhouse for resistance to the sedentary endoparasite root-knot nematode (Meloidogyne incognita acrita CHIT.). Some of the seedlings and parents and almost all the VR hybrids showed resistance to the nematode and ratings were verified by retesting. The heritability was estimated tobe 0.391 ± 0.06. The expected average gain of the progeny of randomly mated parents ranked in the upper 5 % of the parental generation were calculated. The result indicates that relatively rapid genetic gain is to be expected in the population based on their own performance and subsequent mating, inter se, without use of the more expensive methods of progeny testing and inbreeding which are used to exploit non-additive portions of the genetic variability.The uses of the resistant plants as rootstocks and the langer term combination with desirable economic characters are discussed.Die Heritabilität der Resistenz gegen Wurzelgallennematoden (Meloidogyne incognita acrita CHIT.) bei Vitis-vinifera x V.-rotundifolia-KreuzungsnachkommenEine Population von 807 Nachkommen aus 46 Familien, die aus Kreuzungen zwischen 26 Eltern (Quasi-F1-Kreuzungen aus Vitis vinifera und V. rotundifolia) hervorgegangen sind, die Eltern selbst, 12 V.-vinifera x V.-rotundifolia-Kreuzungen (VR) sowie Muskat von Alexandria und Dogridge als Kontrollen wurden in einer Rebanlage der Universität von Kalifornien, Davis, herangezogen und im Gewächshaus auf ihre Resistenz gegen das endoparasitische Wurzelgallenälchen Meloidogyne incognita acrita CHIT. geprüft. Verschiedene Sämlinge und Eltern sowie fast alle VR-Kreuzungen zeigten Nematodenresistenz; die Ergebnisse wurden durch eine zweite Resistenzprüfung bestätigt.Die Heritabilität wurde auf 0,391 ± 0,06 geschätzt. Die durchschnittlich zu erwartende Verbesserung der Resistenz in der Nachkommenschaft aus zufällig gekreuzten Eltern, die unter den oberen 5 % ihrer Generation rangierten, wurde errechnet. Das Ergebnis zeigt, daß eine relativ rasche genetische Verbesserung erwartet werden kann, wenn sich die Reben einer leistungsfähigen Population zufällig untereinander kreuzen können. Aufwendigere Methoden der Sämlingsprüfung und der Inzucht, durch welche üblicherweise die nichtadditiven Anteile der genetischen Variabilität ausgenützt werden, erübrigen sich dann.Die Verwendung der resistenten Reben als Unterlagen und, längerfristig, zur Kombination von Resistenz und wünschenswerten Eigenschaften der Trauben werden diskutiert

Resistance to grape phylloxera in Vitis vinifera x V. rotundifolia grape hybrids

A population of 278 offspring generated by crosses among 26 parents (some quasi F1 hybrids of Vitis vinifera x V. rotundifolia), some of the parents, 3 V. vinifera x V. rotundifolia hybrids (VR), Muscat of Alexandria (susceptible control), and V. rupestris du Lot (St. George) (resistant control), all grown in the vineyard of the University of California at Davis, were tested in a greenhouse for resistance to the grape phylloxera, Phylloxera vitifoliae FITCH. Some of the seedlings, a parent, and the 3 VR hybrids showed resistance to the pest and verified by retesting. The uses of the resistant plants as rootstocks or in a vine breeding project are discussed.Die Reblausresistenz von Vitis-vinifera x V.-rotundifolia-KreuzungenEine Population von 278 Nachkommen aus Kreuzungen zwischen 26 Elternreben (Quasi-F1-Bastarde aus Vitis vinifera x V. rotundifolia), etliche dieser Eltern, 3 V.- vinifera x V.-rotundifolia-Kreuzungen (VR), Muskat von Alexandria als anfällige Kontrolle sowie V. rupestris du Lot (St. George) als resistente Kontrolle - sämtliche Reben aus einer Anlage der Universität von Kalifornien, Davis - wurden im Gewächshaus auf die Resistenz ihrer Wurzeln gegen die Reblaus geprüft. Einige der Sämlinge, 1 Elternrebe und die 3 VR-Kreuzungen erwiesen sich, auch bei einer zweiten Prüfung, als reblausresistent. Die Verwendung der resistenten Reben als Unterlagen oder zur Züchtung von Ertragsreben wird diskutiert

Identification of stable QTLs for vegetative and reproductive traits in the microvine (Vitis vinifera L.) using the 18 K Infinium chip

UMR AGAP - équipe DAAV - Diversité, adaptation et amélioration de la vigne[b]Background[/b] [br/]The increasing temperature associated with climate change impacts grapevine phenology and development with critical effects on grape yield and composition. Plant breeding has the potential to deliver new cultivars with stable yield and quality under warmer climate conditions, but this requires the identification of stable genetic determinants. This study tested the potentialities of the microvine to boost genetics in grapevine. A mapping population of 129 microvines derived from Picovine x Ugni Blanc flb, was genotyped with the Illumina® 18 K SNP (Single Nucleotide Polymorphism) chip. Forty-three vegetative and reproductive traits were phenotyped outdoors over four cropping cycles, and a subset of 22 traits over two cropping cycles in growth rooms with two contrasted temperatures, in order to map stable QTLs (Quantitative Trait Loci). [br/][b]Results[/b] [br/]Ten stable QTLs for berry development and quality or leaf area were identified on the parental maps. A new major QTL explaining up to 44 % of total variance of berry weight was identified on chromosome 7 in Ugni Blanc flb, and co-localized with QTLs for seed number (up to 76 % total variance), major berry acids at green lag phase (up to 35 %), and other yield components (up to 25 %). In addition, a minor QTL for leaf area was found on chromosome 4 of the same parent. In contrast, only minor QTLs for berry acidity and leaf area could be found as moderately stable in Picovine. None of the transporters recently identified as mutated in low acidity apples or Cucurbits were included in the several hundreds of candidate genes underlying the above berry QTLs, which could be reduced to a few dozen candidate genes when a priori pertinent biological functions and organ specific expression were considered. [br/][b]Conclusions[/b] [br/]This study combining the use of microvine and a high throughput genotyping technology was innovative for grapevine genetics. It allowed the identification of 10 stable QTLs, including the first berry acidity QTLs reported so far in a Vitis vinifera intra-specific cross. Robustness of a set of QTLs was assessed with respect to temperature variatio

Biochar successfully replaces activated charcoal for in vitro culture of two white poplar clones reducing ethylene concentration

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