Pepelnica jagode

Pepelnica je zadnjih godina postala značajna bolest jagoda u Hrvatskoj. Uzročnik je fitopatogena gljiva Podosphaera aphanis, koje je prije bila poznata pod nazivom Sphaerotheca macularis f. fragariae. Za razliku do većine drugih pepelnica simptomi pepelnice na jagodama ne javljaju se prevenstveno u vidu pepeljaste prevlake, već više u vidu uvijanja listova i crvenila na naličju lista. Za suzbijanje se koriste kemijski erisficidi i biofungicidi. Od biofungicida to su bakteriofungicidi na bazi antagonističkih bakterija Bacillus amyloliquefaciens i Bacillus pumilus te mikofungicidi na bazi antagonističke mikoparazitske gljive Ampelomyces quisqualis.

Leveillula guilanensis (Erysiphales, Ascomycota): a new record from Europe with notes on the biogeography of the genus

Powdery mildews are the subject of intense research due to their negative impact on agriculture or horticulture. The genetic diversity of these ascomycete fungi has only been surveyed in the last decades to investigate phylogenetic relationships and species boundaries, to propose new taxa, and to assess their biogeographic history. However, many of the resulting studies are revealing only a partial picture because of the uneven species sampling across the globe. Here, we studied three Leveillula collections occurring on wild plant species in the Iberian Peninsula, a region which lacked any previous knowledge on the genus’ genetic diversity. Our study provides the first record of L. guilanensis in Europe based on specimens from two distant localities in the Iberian Peninsula; the species was so far known only from Iran. It grew on living Chondrilla juncea and was parasitized by the hyperparasite fungus Ampelomyces quisqualis. The morphological and phylogenetic assignment of another collection to L. lanuginosa is reported as well. Furthermore, we inferred a chronogram based on an Erysiphales nrITS substitution rate that dated the crown node of Leveillula back to 22.48 million years ago. Clades including the Iberian Peninsula samples originated and diversified through the Neogene (Miocene to Pleistocene). These results suggest an overall older time frame for the evolution of Leveillula compared to previous works. All in all, the present study provides additional avenues for discussing the evolutionary and biogeographic history of this genus of powdery mildews.

Морфология и круг хозяев Ampelomyces quisqualis Ces. ex Schlecht. в Заилийском Алатау

Анализ полученных данных показал, что гиперпаразит Ampelomyces quisqualis Ces. ex Schlecht.чаще всего встречается на возбудителях мучнистой росы у растений семейств Asteraceae и Lamiaceae. ВпервыеAmpelomyces quisqualis обнаружен на возбудителях мучнистой росы на представителях семейств Elaeagnaceae иHypericaceae. Гиперпаразит был обнаружен на 10 различных видах мучнисторосяных грибов, наиболее часто – напредставителях рода Erysiphe. Размеры пикнид варьировали в диапазоне 30,0–105,0 × 25,0–50,0 мкм и конидий –3,5–7,0 × 1,5–3,5 мкм. Размеры пикнид Ampelomyces quisqualis на различных хозяевах близки между собой, однако большие размеры пикнид наблюдаются на Hieracium virosum Pall., а меньшие – на Stachys sylvatica L.

Preliminary evaluation of the effect of Ampelomyces quisqualis on the degree of plant infestation with selected Erysiphales species proposed as potential bioindicators

In the year 2000 Ampelomyces quisqualis was noted, with various intensity, in north-eastern Poland on different species of Erysiphales selected as potential bioindicators of urban pollution. The results of observation of Erysiphe sordida (on Plantago major), Sphaeroteca erigerontis-canadensis (on Taraxacum officinale) and Microsphaera hypophylla (on Quercus robur) – susceptible species, and Microsphaera palczewskii (on Caragana arborescens) – a resistant species, suggest that A. quisqualis shows affinity to some hosts regardless of their individual reactions to the level and range of anthropopressure. It clearly prefers the genera: Erysiphe and Sphaerotheca. Its effect on the degree of host plant infestation with powdery mildew under natural conditions seems insignificant.

Distribution of cucurbit powdery mildew species in the Czech Republic

The occurrence of Erysiphe cichoracearum (Ec) and Sphaerotheca fuliginea (Sf), causal agents of cucurbit powdery mildew<br />in the Czech Republic (CR) was studied in the period of 1995–2001. Nearly 800 leaf samples with disease symptoms<br />were microscopically examined. Ec is the predominating species, detected on 98% of locations. It was accompanied by Sf<br />on 24% of locations. The occurrence of Sf as the only powdery mildew species was proved on 2% of locations. Recent<br />occurrence of Sf in the CR corresponds with data on Sf fast spreading and prevailing on cucurbits in West and South<br />Europe. However, Ec is the strongly predominating powdery mildew species largely distributed throughout the country.<br />The hyperparasitic fungus Ampelomyces quisqualis was detected on 30% of samples.