Detected changes of population structure within a Cryphonectria parasitica population at the site Osoj, North Macedonia, during a time-span of over two decades
Journal
Book of Abstracts, Intern. Sci. Conf. Better Forestry, for Better Forest, for a Better Planet, "Hans Em" Faculty for Forest Sciences, Landscape Architecture and Environmental Engineering, Skopje
Date Issued
2022-06
Author(s)
Risteski, Mihajlo
Cokoski, Kristijan
Tanovski, Vladimir
Abstract
Cryphonectria parasitica is historically considered as one of the most threatening
plant diseases, and affects several species of Castanea worldwide. Applicability and
success of control measures for the pathogenic fungus, consequently for control of
its impact on European sweet chestnut Castanea sativa is highly dependent on
presence of hypovirulence on populational levels, as well as on the population
structure characteristics, most prominently vc-type diversity. In this study we
compared the main characteristics of isolates of C. parasitica collected on 2
occasions with a time gap of 22 years (1998 and 2020) from the same site Osoj in
the Kicevo region, in North Macedonia. We analyzed culture morphology, v-c type,
and presence of hypovirulence of 72 isolates collected in 1998 and 39 isolates in
2020, by standard methods in vitro. In terms of the v-c type, from the total of 72
isolates collected in 1998, 49 (68%) were EU-12, 22 (30,55%) were EU-2 and 1
(1,38%) was EU-1. Of the 39 isolates collected in 2020, 32 (82%) were EU-12, 7
(18%) were EU-2, and no other vc types were detected, including EU-1. In 1998, 7
(13%) out of 54 assessed isolates were designated as hypovirulent, while in 2020 the
proportion of hypovirulent isolates was much increased (33.33%), i.e. 13 of the total
of 39. For the two-decade time frame, v-c type EU-12 remained dominant, with an
additional increment of its prevalence on the populational level. From a practical point
of view, it is more important that prevalence of hypovirulence was increased by over
two-fold (x 2.57). This is likely the most important reason for difficulty during collection
of viable samples, ultimately leading to a much lesser number of samples collected
in 2020. As a conclusion, the C. parasitica population in Osoj has not only not
diversified, but the most dominant vc type has become even more established with
time. The relatively high proportion of hypovirulent isolates and the large increment
detected in just over two decades timeframe, is interesting to further investigate in
relation to overall health status of the chestnut population in Osoj
plant diseases, and affects several species of Castanea worldwide. Applicability and
success of control measures for the pathogenic fungus, consequently for control of
its impact on European sweet chestnut Castanea sativa is highly dependent on
presence of hypovirulence on populational levels, as well as on the population
structure characteristics, most prominently vc-type diversity. In this study we
compared the main characteristics of isolates of C. parasitica collected on 2
occasions with a time gap of 22 years (1998 and 2020) from the same site Osoj in
the Kicevo region, in North Macedonia. We analyzed culture morphology, v-c type,
and presence of hypovirulence of 72 isolates collected in 1998 and 39 isolates in
2020, by standard methods in vitro. In terms of the v-c type, from the total of 72
isolates collected in 1998, 49 (68%) were EU-12, 22 (30,55%) were EU-2 and 1
(1,38%) was EU-1. Of the 39 isolates collected in 2020, 32 (82%) were EU-12, 7
(18%) were EU-2, and no other vc types were detected, including EU-1. In 1998, 7
(13%) out of 54 assessed isolates were designated as hypovirulent, while in 2020 the
proportion of hypovirulent isolates was much increased (33.33%), i.e. 13 of the total
of 39. For the two-decade time frame, v-c type EU-12 remained dominant, with an
additional increment of its prevalence on the populational level. From a practical point
of view, it is more important that prevalence of hypovirulence was increased by over
two-fold (x 2.57). This is likely the most important reason for difficulty during collection
of viable samples, ultimately leading to a much lesser number of samples collected
in 2020. As a conclusion, the C. parasitica population in Osoj has not only not
diversified, but the most dominant vc type has become even more established with
time. The relatively high proportion of hypovirulent isolates and the large increment
detected in just over two decades timeframe, is interesting to further investigate in
relation to overall health status of the chestnut population in Osoj
Subjects