Naslov
Maturation of Ascospores of Venturia inaequalis (Cke.) Wint. in leaves of some apple cultivars

Autori
Cvjetković, Bogdan ; Mikec, Ivan

Izvornik
Acta Phytopathologica et Entomologica Hungarica (0238-1249) 27 (1992), 1-4; 189-196

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Ventiria inaequalis, ascospore, maturation

Sažetak
MATURATION OF ASCOSPORES OF VENTURIA INAEQUALIS (CKE.) WINT. IN LEAVES OF SOME APPLE CULTIVARS-For two years we observed the formation of pseudotheci, asci and ascospores on overwintering leaves of different cultivars (Golden Delicious, Idared, Jonagold, Gloster, Mutsu, Jonathan) in the spring. Results show a difference in formation times of pseudotheci between cultivars. We also noticed that ascospores matured at different times. The same experiment showed that some cultivars have a shorter and some a longer period of ascospore discharge. Apple scab (Venturia inaequalis) is the most important disease of apple in our country. Control measures for scab rely on fungicide sprays during the period of ascospore production. Thus, an understanding of ascospore productivity, maturation and release is fundamental to an effective and efficient control program. As there is a difference in the level of sensitivity between apple cultivars, we assumed that there should be a difference in the length of the saprophytic phase of different cultivars. This has been pointed out by several authors (Gilpatrick and Szkolnik, 1976). In the autumn we collected the fallen leaves from trees on which apple scab had been registered in order to detect, whether a difference in pseudotheci ripening existed on leaves of various apple cultivars (Golden Delicious, Idared, Jonagold, Gloster, Mutsu, Jonathan) growed in the same orchard. The tress were of similar age from 6 to 8 years. The leaves were held during the winter in natural conditions. The pseudotheci and their maturing contents were observed from the 15th of March. From the data we weekly took 10 overwintered leaves from each variety, washed them with destilled water and observed them under a binocular lens. When pseudotheci were found we took 5-6 of them from each leaf, crushed them and observed with a microscope. In this way we registered the appearance of pseudotheci asci, ascospores in them and estimated their maturity using Szkolnik's method (Szkolnik, 1962). We classified them into the following categories: a) Pseudotheci present, asci and ascospores not evident, b)Formed asci with colored ascospores ; c)Ascospores discharged The results obtained are presented graphically.

Izvorni jezik
Engleski

Znanstvena područja
Poljoprivreda (agronomija)

Napomena
ISI No.: JQ231// CAB Accession Number: 19932329360

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