Acta Univ. Agric. Silvic. Mendelianae Brun. 2018, 66, 1191-1197

https://doi.org/10.11118/actaun201866051191
Published online 2018-10-29

Significance of Sexual Reproduction of Phytophthora infestans in the Czech Republic

Jana Mazáková, Miloslav Zouhar, Pavel Ryšánek

Department of Plant Protection, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, 165 00 Prague, Czech Republic

A total of 187 naturally late blight‑diseased potato leaves were sampled from 31 sites and five regions of the Czech Republic during the growing season in 2012–2014 and 2016 and examined microscopically for the ability of Phytophthora infestans to produce oospores in infected leaves under field conditions. Although the occurrence of the A1 and A2 mating types required for sexual reproduction of P. infestans was previously confirmed in the Czech Republic, no oospores were detected in this study. To study the effect of temperature on the survival of oospores produced from crosses of three pairs of P. infestans isolates, oospores in leaf discs and agar were exposed to temperatures ranging from –24 to 10 °C and then evaluated for viability with the plasmolysis test. Oospore viability ranged from 13.02 to 63.90 % and from 7.77 to 63.37 % for oospores produced in agar and leaf discs, respectively, with the highest frequencies of viable oospores occurring at 4 and 10 °C. To determine whether oospores may survive under field conditions, agar plates with oospores were buried in soil in Prague‑Suchdol and Svitavy for seven months during the overwintering period (October–May) in 2011–2015. There were statistically significant differences in oospore viability examined by the plasmolysis test between the localities, and oospore viability ranged from 29 to 43 % and from 15 to 44 % in Prague‑Suchdol and Svitavy, respectively.

Funding

Supported by the Ministry of Agriculture of the Czech Republic, Project No. QJ1210305.

References

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