Tag Archives: powdery mildew

721-728 G. Statkevičiūtė and A. Leistrumaitė
Modern varieties of spring barley as a genetic resource for disease resistance breeding
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Modern varieties of spring barley as a genetic resource for disease resistance breeding

G. Statkevičiūtė and A. Leistrumaitė

Cereal Breeding Department, Institute of Agriculture, Lithuanian Research Centre forAgriculture and Forestry, Instituto av. 1, Akademija, Kedainiai distr., LT 58344,Lithuania; e-mail: grazinastat@lzi.lt

Abstract:

The large variation in net blotch resistance is observed among barley germplasm, but the range of European commercial cultivars of spring barley have various degree of susceptibility. This study was designed to test 150 West European ecotype spring barley varieties and breeding lines in the field for resistance to net blotch (Pyrenophora teres) and powdery mildew (Blumeria graminis f.sp. hordei) and to provide information for a successful resistance–breeding program in spring barley under Lithuanian conditions. The experiment was conducted at the Institute of Agriculture of the Lithuanian Research Centre for Agriculture and Forestry. The effectiveness of different methods of artificial inoculation was also tested. About 50 varieties with net blotch resistance level ranging from resistant/moderately resistant to susceptible were chosen for agro-biological trait evaluation. Increased net blotch infection had a negative impact on ear length, number of spikelets and number of grains in the ear in 2007. No significant effects on these traits were found in 2009, but increased net blotch level caused significantly lower grain weight per ear. Artificial inoculation using chopped straw of susceptible varieties is more likely to give desirable effects on infection level. The varieties ‘Luokė’, ‘Otis’, ‘Anni’, ‘Landora’, ‘Beatrix’ possessed the highest resistance to net blotch, and the varieties ‘Marnie’ and ‘Isotta’ exhibited good resistance to powdery mildew. The variety ‘Acrobat’ was resistant to both diseases.

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231-236 I. Kokina and I. Rashal
Monitoring the population of Blumeria graminis f. sp. hordei in the South-Eastern part of Latvia
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Monitoring the population of Blumeria graminis f. sp. hordei in the South-Eastern part of Latvia

I. Kokina¹ and I. Rashal²

¹Department of Biology, University of Daugavpils, Vienības Str. 13, LV-5401, Latvia;e-mail: inese.kokina@navigator.lv;
²Institute of Biology, University of Latvia, Miera Str. 3, Salaspils, LV-2169, Latvia;e-mail: izaks@email.lubi.edu.lv

Abstract:

The population of Blumeria graminis f.sp. hordei in the South-Eastern part of Latvia (Latgale region) has been monitored since 1995. In 2005, samples of the pathogen were collected both as conidia and cleistothecia from commercial barley fields. Frequencies of virulence genes, pathotypes and their complexity were calculated. Genes Va1, Va3 and Va13 were presented with medium-high frequencies and frequencies of Va6, Va7, Va9, Va12, Vk and VLa ranged from medium-high to high. A large number of pathotypes was detected, which reflects wide genetic diversity in the pathogen population.

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549-562 Y. Tomason and P.T. Gibson
Fungal characteristics and varietal reactions of powdery mildew species on cucurbits in the steppes of Ukraine
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Fungal characteristics and varietal reactions of powdery mildew species on cucurbits in the steppes of Ukraine

Y. Tomason¹ and P.T. Gibson²

¹Department of Selection and Seed Production, Dnepropetrovsk State Agrarian University,Voroshilov 25, 49600 Dnepropetrovsk, Ukraine; e-mail: yantomason75@mail.ru
² Department of Plant, Soil and Agriculture Systems, Southern Illinois University, 62901,Carbondale, IL, USA; e-mail: pgibson@siu.edu

Abstract:

Powdery mildew caused by fungal species Sphaerotheca fuliginea (Schlect ex. Fr.) Poll. [syn. Podosphaera xanthii (sect. Sphaerotheca) xanthii (Castag.) U. Braun & N. Shish. Comb. nov.] and Erysiphe cichoracearum D.C. [syn. Golovinomyces cichoracearum (D.C.) Huleta] is the most frequent cucurbit (Cucurbitaceae) crop disease in the northern steppes of Ukraine. Species commonly cultivated in Ukraine (melon, watermelon, squash) were colonized by both species. Ash gourd (Benincasa hispida Cogn.) and bottle gourd (Lagenaria siceraria Standl.) were colonized only by E. cichoracearum. Sponge gourd (Luffa cylindrica M.J. Roem) and fig-leaved gourd (Cucurbita ficifolia L.) were not colonized by either of these fungi. Varieties within species varied from resistant to highly susceptible. Four melon varieties were agronomically elite and had resistance to both species. Those two species were consistently differentiated by the location on the conidia where germination occurred, and by the ratio of conidial length to width. Indicator host species and varieties can provide a tentative identification of which powdery mildew species are present in the field.Varietal differentials suggested that races 1 & 2 of S. fuliginea were present onwatermelon, and that race 1 and at least one other race were present on melon.

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