Ten Years of VINQUEST: First Insight for Breeding New Apple Cultivars with Durable Apple Scab Resistance

Apple scab, caused by Venturia inaequalis, is a major fungal disease worldwide. Cultivation of scab-resistant cultivars would reduce the chemical footprint of apple production. However, new apple cultivars carrying durable resistances should be developed to prevent or at least slow the breakdown of resistance against races of V. inaequalis. One way to achieve durable resistance is to pyramid multiple scab resistance genes in a cultivar. The choice of the resistance genes to be combined in the pyramids should take into account the frequency of resistance breakdown and the geographical distribution of apple scab isolates able to cause such breakdowns. In order to acquire this information and to make it available to apple breeders, the VINQUEST project (www.vinquest.ch) was initiated in 2009. Ten years after launching this project, 24 partners from 14 countries regularly contribute data. From 2009 to 2018, nearly 9,000 data points have been collected. This information has been used to identify the most promising apple scab resistance genes for developing cultivars with durable resistance, which to date are: Rvi5, Rvi11, Rvi12, Rvi14, and Rvi15. As expected, Rvi1, together with Rvi3 and Rvi8, were often overcome, and have little value for scab resistance breeding. Rvi10 may also belong to this group. On the other hand, Rvi2, Rvi4, Rvi6, Rvi7, Rvi9, and Rvi13 are still useful for breeding, but their use is recommended only in extended pyramids of $3 resistance genes

PERIPHERAL anti-p n PRODUCTION AND DECAY ANGULAR DISTRIBUTIONS IN THE REACTION pi- p ---> (anti-p N) p AT 12-GeV/c INCIDENT MOMENTUM

The reaction pi /sup -/p to (pn)p/sub s/, where p/sub s/ is a slow proton, was measured at 12 GeV/c incident momentum with the CERN-OMEGA spectrometer. Both antiproton and proton were identified uniquely by electronics information. 1844 events with four-momentum transfer squared in the range 0.13<or= mod t mod <or=0.33 GeV/sup 2/ and with invariant masses M(pn) up to 2.5 GeV were obtained. The corresponding cross section in this t range is determined to be sigma =4+or-0.4 mu b. Extrapolating the differential cross section over the whole t range assuming d sigma /dt approximately exp(5.3 t) a cross section of sigma =9.3+or-2.0 mu b is estimated. Comparison is made with data on pi /sup -/p to (pp)n/sub s/ (where n/sub s/ is a slow neutron) in the same t range. (12 refs)

RESULTS FROM A SLOW PROTON TRIGGER EXPERIMENT AT 12-GeV/c

A study of the reaction \u3c0-p \u2192 X-p based on 1.27 7 106 events, corresponding to a mean sensitivity of 200 events/\u3bcb, is presented. Properties of the exclusive channels \u3c0-p \u2192 \u3c0-\u3c00p, \u3c0+\u3c0-\u3c0-p, \u3c0+\u3c0-\u3c0-\u3c00p, \u3c0+\u3c0+\u3c0-\u3c0-\u3c0-p and \u3c0+\u3c0+\u3c0-\u3c0-\u3c0-\u3c00p are discussed

Ten years of VINQUEST: first findings

Apple scab, caused by Venturia inaequalis, is a major disease worldwide. To control this disease, up to 20-25 fungicide applications may be needed depending on the year and the production system. Cultivation of scab-resistant apple cultivars would reduce the chemical footprint of apple production. Breeding for durable scab resistance is an objective of most apple breeding programmes. One way to achieve durable resistance is to pyramid multiple apple scab resistance genes in a cultivar. Currently, more than 18 different apple scab resistance genes have been reported. Molecular markers are available for most of these and can be used to select seedlings carrying multiple resistance genes. Apple scab isolates are virulent to specific apple scab resistance genes. Choice of optimal resistance genes for use in a breeding program, should therefore take regional presence of these apple scab isolates into consideration. In order to learn more about the geographical distribution of apple scab isolates, the VINQUEST project (www.vinquest.ch) was initiated in 2009. Ten years after the launch of this initiative, 24 partners from 14 countries are regularly contributing data. Results obtained from the data collected during the first 10 years provide the first insights into which apple scab resistance genes may hold most promise for breeding cultivars with durable resistance

OBSERVATION IN THE K+ K- SYSTEM OF A NEW STRUCTURE AT 2.2-GEV

A sample of 56909 events of the reaction pi /sup -/p to K/sup +/K/sup -/n at 10 GeV/c has been measured in the Omega spectrometer at CERN. In the K/sup +/K/sup -/ system, besides production of mesons in the S* / phi , f/sup 0//A/sub 2/, g/ omega * and h regions the authors observe a new structure at 2.20 GeV with a width of the order of 200 MeV. (10 refs)