American Gooseberry Mildew Research Articles

Genetic diversity in gooseberry (Ribes uva-crispa), as estimated with SSR markers

• Two hundred forty two gooseberry accessions were analysed by 15 SSR markers enabling the identification of 153 unique genotypes. • The genetic diversity of the analysed accessions indicated a slightly negative assortative mating as expected for an outcrossing species. • Cultivars that have been wide spread in cultivation in sweden had a large number of synonymous samples. • The studied genotypes clustered into four posterior groups corresponding to the three a priori anticipated groups: old cultivars, modern cultivars, eastern cultivars, and an additional northern swedish cluster. • Pedigrees for a number of cultivars were confirmed and supported the true-to-typeness of the involved accessions. Additionally three likely parent-parent-offspring relationships were identified. European gooseberry ( Ribes uva-crispa L. ) is a popular berry crop in many European countries, including Sweden, Denmark and Ukraine. There is no active gooseberry breeding programme in either Sweden or Denmark, but a successful programme is operating in Ukraine. In Sweden and Denmark, research on gooseberries is primarily focused on collection and phenotypic evaluation of genetic resources. As part of these activities, a large number of inventory finds have been collected but have not yet been characterised morphologically or molecularly. The goal of this study was thus to characterise gooseberry germplasm with 15 simple sequence repeat (SSR) markers. From 242 accessions analysed, 153 unique genotypes were identified. Cultivars that have been in widespread cultivation in Sweden, such as the Finnish cultivars ‘Hinnonmäen Keltainen’ and ‘Hinnonmäen Punainen’, had relatively large numbers of synonymous samples. While many inventory finds were identifiable as synonyms of known cultivars, several were found to constitute unique genotypes within the germplasm studied. The studied genotypes clustered relatively well in three posterior groups, consisting of cultivars originating before and after the American gooseberry mildew ( Sphaerotheca mors-uvae ) outbreak around 1900 and cultivars originating from the territory of the former Soviet Union. A fourth genetic cluster consisting mainly of inventory finds from central and northern Sweden was also identified. In addition, it was possible to verify recorded and stipulated parentages for some of the cultivars studied and to identify three likely parent-parent-child trios. Thus, inventories of local gooseberry germplasm and a subsequent genotyping proved successful in finding unique local genotypes, with potential local adaptation. The data obtained provide a foundation for future studies of gooseberry genetic resources, while also illustrating the importance of a well-curated and phenotypically characterised set of reference cultivars for future studies.

Environmental assessment of gooseberry cultivars developed in Chelyabinsk Province

The analysis of environmental plasticity and stability made it possible to identify adaptable gooseberry cultivars: ‘Avangard’ (CA = 1.77), ‘Vladil’ (CA = 1.58), ‘Grinchel’ (CA = 1.24), ‘Kovcheg’ (CA = 1.13) and ‘Arlekin’ (CA = 1.01). Cv. ‘Grinchel’, submitted for state trials in 2020, is an intensive-type cultivar (bi = 1.49), cvs. ‘Arlekin’ (bi = 1.03; Si2 = 4.1) and ‘Vladil’ (bi =1.03; Si2 = 1.0) are environmentally plastic and stable, while cvs. ‘Avangard’ (bi = 0.51) and ‘Kovcheg’ (bi = 0.53) belong to the neutral type. The advantages of these cultivars are their high productivity, large fruit size, dessert flavor, high winter hardiness, low thorniness, and increased resistance to American gooseberry mildew. High productivity in years with favorable and satisfactory growing conditions can be provided by the intensive-type cultivars ‘Stanichny’ (bi = 1.55) and ‘Kooperator’ (bi = 1.35) as well as the plastic but insufficiently stable cv. ‘Uralsky Izumrud’ (bi = 1.03; Si2= 5.3).

Luna Sensation 500 SC – nowy fungicyd do zwalczania chorób porzeczki czarnej

Summary American gooseberry mildew (Podosphaera mors-uvae), leaf spot (Drepanopeziza ribis) and white pine blister rust (Cronartium ribicola) are the most severe fungal diseases of black currant (Ribes nigrum). On commercial plantations control of these diseases is based mainly on the chemical method. However, the assortment of currently registered fungicides is limited to three products. The experiments, performed in 2010–2011 with new fungicide Luna Sensation 500 SC containing fluopyram and trifloxystrobin, showed its high effectiveness in control of black currant diseases. This fungicide applied at the doses of 0.6 and 0.8 l/ha very effectively controlled American gooseberry mildew (over 96%), leaf spot (over 88%) and white pine blister rust (over 82%). The effectiveness of Luna Sensation 500 SC was similar or higher than commonly used fungicides such as Score 250 EC and Signum 33 WG, thus it can be a suitable candidate recommended for efficient control of black currant fungal diseases, especially for anti resistant strategy.

The ecological effects of exotic disease resistance genes introgressed into British gooseberries

The potential for gene flow between crops and their wild relatives is now well established. However, few studies have investigated the effects of crop genes on fitness in natural populations, or the indirect ecological consequences of their naturalization. This study investigates the likelihood of genes derived from North American gooseberry species (which are resistant to the coevolved American gooseberry mildew) becoming established in mildew-susceptible native British gooseberries, and the impact of this on their invertebrate herbivores. The results reveal that seedlings containing resistance genes had significantly higher survival rates than susceptible native plants. Alien genes were more likely to establish when introgressed into native genomes and when crossed with local provenance genotypes. Furthermore, plants containing alien genes tended to support significantly more but smaller invertebrates. Thus, the potential ecological effects of crop gene escape may vary with source and recipient genome and such effects may not be directly related to the gene's function.

COVERCROPS IN BLACKCURRANT (RIBES NIGRUM)

With the objective to identify the effect of soil cultivation and nitrogen supply in organic production of blackcurrant a field trial was planted autumn 1996 under unsprayed conditions. The bush rows were cleaned mechanically for weed, and cover crops were established in the alleyways. During establishment all four cover crops gave a sufficient nitrogen supply. The level of nitrogen in soil and the growth were smallest in the annual sown cover crop. Miniritzotrons were used to follow blackcurrant root growth in total mechanical cleaned plots and plots with sown alleyways. The maximum root dept of blackcurrants of 125 cm were obtained direct under the bush in autumn 1998, whereas the roots only were present down to 40 cm 1.5 meters from the centre of the row. The variety ‘Titania’ had a deeper root pattern than ‘Ben Lomond’. There were no significant yield differences among the soil treatments. There was a tendency to a higher yield for ‘Titania’ in 2000 in the annual sown cover crop, probably due to the deeper root pattern of ‘Titania’ and thereby less susceptibility to mechanical root damage. ‘Titania’ had the highest yield in the two cropping years 1999 and 2000; whereas, ‘Ben Lomond’ had a very low yield due to severe infections of American gooseberry mildew (Sphaerotheca mors-uvae); which caused very little shoot growth. ‘Farleigh’ was susceptible to white pine blister rust (Cronartium ribicola) and infections of leaf spot (Gloeosporidiella ribis) occurred every year. ‘Titania’ and ‘Intercontinental’ had the best field resistance to diseases.

Alleyway Groundcover Management Impacts on Soil, Pests and Yield Components in Blackcurrants (Ribes nigrum L.)

ABSTRACT Vegetation-free soil was compared with natural weed and white clover (Trifolium repens) alleyways in established blackcurrants from 1992 to 1995. The number of earthworms, the development of the cover crops and the occurrence of diseases and pests were assessed. Soil moisture, nutrient content in leaves, fruit set, yield and juice quality were determined. The cover crops did not influence the number of earthworms. The total number of heaps of casting increased from 2.0 m−2 in 1993 to 16.4 m−2 in 1995 as an average of all treatments. The cover crops did not cause a reduction of American gooseberry mildew (Sphaerotheca mors-uvae), white pine blister rust (Cronartium ribicola) or leaf spot (Gloeosporidiella ribis). The top soil moisture percent was significantly higher during 1995 for blackcurrant cv. Ben Lomond (20.8%) than for cv. Ben More (18.7%) as an average of all treatments. ‘Ben Lomond’ showed no differences in soil moisture between treatments, while the vegetation-free ‘Ben More’ had a slightly higher soil water content than the cover crop treated. Leaf contents of total nitrogen, potassium and magnesium were within the optimal levels and were not affected by the treatments. In three out of four years the yield was identically for the different soil treatments, but in 1995 the fruit set and the yield in the cover cropped ‘Ben Lomond’ was reduced compared to the vegetation-free bushes.

The mildew resistance gene Sph 2in relation to gall mite resistance in the black currant

In black currant progenies derived from parents heterozygous for resistance to American gooseberry mildew. Sphaerotheca mors-uvae (Schw.) Berk., and to gall mite, Cecidophyopsis ribisWestw. (genes Sph2from the Swedish cultivar Ojebyn and Ce from Ribes grossularia L., respectively), there is invariably a defieit of mildew resistant plants. Linkage in repulsion between Sph2and Ce would account for the significantly greater deficit of mildew resistants in the gall mite resistant class. In contrast with published data for the mildew resistance gene Sph3, there is no evidence of linkage of Sph2with the leafing out gene Lf1, suggesting that the gene order is Sph2-Ce-Lf1-Sph3.

Resistance to the gall mite and American gooseberry mildew in black currants in relation to season of leafing out

In black currant (Ribes nigrum) backcross progenies segregating for resistance to the gall mite, Cecidophyopsis ribisWestw. (gene Ce from Ribes grossularia L.), and to American gooseberry mildew, Sphaerotheca mors-uvae (Schw.) Berk. (gene Sph3from R. glutinosum), significant differences in season of leafing out occurred between the resistant and susceptible classes. The data are consistent with the hypothesis that two additive genes, Lf1and Lf2, controlled season of leafing out and that Ce and Sph3 were linked with Lf1.

Ribes glutinosum and R. Sanguineum as donors of resistance to American gooseberry mildew in black currant breeding

A major dominant resistance gene Sph3 has been transferred from Ribes ‘carrierei’ (R. glutinosum albidum × R. nigrum) to black currants of commercial promise by backcrossing repeatedly to R.nigrum. Probable causes of the almost invariable deficit of resistant plants in segregating progenies are briefly discussed. Response of young seedlings to mildew in the glasshouse was very highly correlated with their field response as mature plants.

North European cultivars as donors of resistance to American gooseberry mildew in black currant breeding

The Swedish black currant Ojebyn is heterozygous for a dominant gene, designated Sph2, conferring effective resistance against Sphaerotheca mors-uvae at East Malling. Resistance due to the gene M derived from the Finnish Brodtorp is now often only partial and in some progenies is associated with an undesirable spreading habit. Size differences in the satellites of the two nucleolar chromosomes of Brodtorp are not closely associted with differential mildew response in its derivatives.

Breeding for resistance to American gooseberry mildew, Sphaerotheca mors‐uvae, in the gooseberry (Ribes grossularia)

SUMMARYStrong resistance to American gooseberry mildew (Sphaerotheca mors‐uvae) occurred in eight out of ten F1 progenies from crosses of resistant North American Eugrossularia species with European gooseberry cultivars or seedlings. Bimodal segregations in four of these F1's and in one F1 derived from the wild European Ribes grossularia uva‐crispa suggested that each donor carried a major dominant resistance gene. Such a gene, Sph1 was identified in a first backcross from R. oxyacanthoides.Accessions of R. oxyacanthoides, R. leptanthum and R. watsonianum proved the most promising donors of resistance to mildew and leaf spot (Pseudopeziza ribis).

The life‐history and epidemiology of American gooseberry mildew on black currants

SUMMARYIt is shown that conidia of Sphaerotheca mors‐uvae (Schw.) Berk, from gooseberry readily infect black currant; therefore it is unlikely that a new race of S. mors‐uvae specifically pathogenic to black currants has recently appeared. However, the life‐cycle on black currants differs from that on gooseberry. Incubation, infection and sporulation of the fungus have been examined under the optimum conditions of 18 °C and 100% relative humidity. The establishment of infections and sporulation was encouraged by a relatively low soil moisture content, temperatures above 15 °C, 60% relative humidity and good illumination‐factors which promote vigorous plant growth. High phosphorus and high potassium nutrition also increased the susceptibility of black currants to infection.

The Effect of Simazine on the Incidence of American Gooseberry Mildew on Black Currants

SUMMARYIn 1964, American gooseberry mildew on black currants in a trial in Northamptonshire increased in incidence and severity with increasing rate of application of simazine.

Agricultural and Horticultural Pests

MUCH recent research into the incidence and overwintering of the potato blight fungus (Phytophihora infestans) has made it necessary for the Ministry of Agriculture to revise its leaflet upon this subject. The new Advisory Leaflet, No. 271, shows that the fungus overwinters upon infected tubers, and there are usually sufficient of these left from previous crops, or thrown out from storage pits, to begin fresh infection in the spring. Control by spraying and dusting is described, and other methods include the removal and destruction of haulm before digging the crop, and the disposal of blighted tubers. Advisory Leaflet Np. 273 replaces leaflet No. 195, and deals ttith American gooseberry mildew (Sphceroiheca mors-uvi). The subject-matter has been brought up to date. A short Advisory Leaflet (No. 182) deals with spurrey (Spergula arvensis) as an agricultural weed. Spraying with 5 per cent solution of copper sulphate, or 7-10 per cent sulphuric acid, are recommended for control of the weed amongst cereal crops, in addition to the application of lime, and other methods.

The Control of Plant Diseases

“Be ye ashamed, oh ye husbandmen; howl, oh ye vinedressers, for the wheat and for the barley; because the harvest of the field is perished. I have smitten you with blasting and mildew.” JOEL i. 11 and AMOS iv. 9. TN opening the discussion between Sections K and M on the control of plant diseases, at the Leeds meeting of the British Association, Mrs. N. L. Alcock chose the above text, and passing lightly over the superstitions of the past regarding disease, she turned to the problem of control as seen to-day by the pathologist and agriculturalist. From the practical point of view, the first full recognition of the importance of plant diseases came with the epidemic of American gooseberry mildew. In 1905, Prof. Salmon, of Wye Agricultural College, while Ireland alone of the British Isles was definitely affected by the disease, gave a clear warning of the need of legislative control of both American gooseberry mildew and of potato wart disease. In another direction the warning was spread in 1909 by Prof. Sommerville in his references to the white pine blister rust, Cronartium ribicola, which he stated was still unknown in America, though it was to be feared that the day was not far distant when its footing in North America would be secured. To-day the losses in America due to this disease are credibly reckoned as enormous.

The British Mycological Society

THE Transactions of the British Mycological Society for 1914 (vol. v., part 1; May, 1915; Worcester: E. Baylis and Son) contain a number of interesting x articles. Prof. A. H. R. Buller's presidential address on the fungus lore of the Greeks and Romans shows the various ways in which fungi attracted the attention of the ancients. Those who are adverse to the idea of our various edible kinds of fungi being, considered a valuable source of food will; note that Dio-scorides was so suspicious of all edible fungi (although these were consumed in large quantities by the Greeks and Romans) that he recommended the taking of an emetic after the eating of any kind. Pliny, in referring to the rust of cereals, which he calls “the greatest pest of the crops,” says that it may be averted “by fixing branches of laurel in the fields.” Such kinds of belief die hard; the present writer can recall that when, a few years back, the American gooseberry mildew first invaded Kent, a prominent fruit-farmer announced his intention of planting a hedge of Eucalyptus to ward off this new pest.

The American Gooseberry-mildew

The American Gooseberry-mildew

American Gooseberry Mildew

MR. E. S. Salmon, the mycologist to the South-Eastern Agricultural College at Wye, Kent, is the active leader of an agitation against a mildew affecting gooseberries known as Sphaerotheca mors uvae. The fungus in question is of American extraction, and somehow it was introduced into Ireland about the year 1900; it has since spread, has already effected much mischief, and will undoubtedly cause more.