New sources of resistance to net blotch (Pyrenophora teres f. sp. teres) in collection of barley landraces

Jęczmień należy do ważnych gospodarczo gatunków zbóż a plamistość siatkowana powodowana przez Pyrenophora teres f. sp. teres jest chorobą, która w sposób istotny wpływa na wielkość i jakość plonu ziarna. Dlatego celem badań było zidentyfikowanie źródeł odporności na plamistość siatkowaną jęczmienia w kolekcji odmian miejscowych po zakażeniach sztucznych izolatami o zróżnicowanej wirulencji i awirulencji w stosunku do odmian o znanym stopniu odporności na tego patogena. Badania prowadzono w warunkach kontrolowanych — na fragmentach liści (oceny w skali 1–4) oraz w warunkach szklarniowych i polowych (oceny w skali 1–10). W pierwszym etapie badań zróżnicowano 32 izolaty wyosobnione z prób liści zebranych w różnych rejonach Polski i do dalszych prac wytypowano 15 izolatów. Materiałem roślinnym były 34 odmiany miejscowe pochodzące z Egiptu, Nepalu, Jordanii, Turcji, Portugalii i Grecji. Stopień odporności na pojedyncze izolaty osobno oceniono na fragmentach liści, a następnie w warunkach szklarniowych i polowych zakażano mieszaniną wszystkich izolatów pochodzących z Polski oraz jednym, reprezentującym populację P. teres f. sp. teres występująca na terenie Finlandii. Stwierdzono, że jedna odmiana pochodząca z Turcji oraz jedna odmiana pochodząca z Jordanii są szczególnie cennymi źródłami odporności na plamistość siatkowaną jęczmienia (odporność wyższa w stosunku do wysoko odpornej odmiany wzorcowej CI9819). Jako źródła odporności mogą zostać wykorzystane również trzy odmiany z Nepalu, których odporność była oceniona na poziomie odmiany CI9819.Barley is one of the economically important crop species and net blotch caused by Pyrenophora teres f. sp. teres has a significant impact on the quantity and quality of grain yield. Therefore the aim of the current study was identify sources of resistance to barley net blotch in the collection of landraces. The resistance was assessed after inoculation using isolates with different spectrum of virulence and avirulence, in relation to differential set of genotypes with known level of resistance. The study was carried out under controlled conditions — as detached-leaf test (scale ratings: 1–4) and in a greenhouse and field (scale ratings: 1–10). In the first stage of the study the virulence of 32 isolates was characterized. They were isolated from leaf samples collected in different regions of Poland and for further work 15 isolates were chosen. As a plant material 34 local varieties originating from Egypt, Nepal, Jordan, Turkey, Portugal and Greece were used. Their levels of resistance to specific isolates were evaluated on detached-leaf fragments and then under greenhouse and field conditions using mixture of all Polish isolates and one isolate, representing Finnish P. teres f. sp. teres population. Based on the obtained results it was found, that one landrace originating from Turkey and one landrace originating from Jordan are especially valuable sources of resistance to net blotch of barley (resistance level higher than resistant control cultivar CI9819). Three landraces from Nepal can be also used as sources of resistance. Their levels of resistance were assessed at the level of cultivar CI9819

Pathogenic variation in populations of Drechslera teres f. teres and D. teres f. maculata and differences in host cultivar responses

v2006o

Oral exposure to thiacloprid-based pesticide (Calypso SC480) causes physical poisoning symptoms and impairs the cognitive abilities of bumble bees

BackgroundPesticides are identified as one of the major reasons for the global pollinator decline. However, the sublethal effects of pesticide residue levels found in pollen and nectar on pollinators have been studied little. The aim of our research was to study whether oral exposure to the thiacloprid levels found in pollen and nectar affect the learning and long-term memory of bumble bees. We tested the effects of two exposure levels of thiacloprid-based pesticide (Calypso SC480) on buff-tailed bumble bee (Bombus terrestris) in laboratory utilizing a learning performance and memory tasks designed to be difficult enough to reveal large variations across the individuals.ResultsThe lower exposure level of the thiacloprid-based pesticide impaired the bees' learning performance but not long-term memory compared to the untreated controls. The higher exposure level caused severe acute symptoms, due to which we were not able to test the learning and memory.ConclusionsOur results show that oral exposure to a thiacloprid-based pesticide, calculated based on residue levels found in pollen and nectar, not only causes sublethal effects but also acute lethal effects on bumble bees. Our study underlines an urgent demand for better understanding of pesticide residues in the environment, and of the effects of those residue levels on pollinators. These findings fill the gap in the existing knowledge and help the scientific community and policymakers to enhance the sustainable use of pesticides.Peer reviewe

Chronic oral exposure to Amistar fungicide does not significantly affect colour discrimination but may impact memory retention in bumblebees

BackgroundIntensive agriculture, including pesticides, is one of the many reasons for pollinator decline. The EU legislation on plant protection products (hereon pesticides) demands that the risks of active substances and their use in pesticide products are assessed for bees. However, the risk assessment is not always sufficient as shown, for example, in the case of the fungicide Amistar. The fungicide has been shown to cause lethal and sublethal effects on bumblebees at levels that, according to the EU risk assessment, do not require risk mitigation measures to protect bees. In order to understand the effects of chronic Amistar exposure on bumblebees, we studied whether 5 days of oral exposure to 0.015 mu l Amistar (3.75 mu g azoxystrobin/day) impairs bumblebees' learning and memory performance in the 10-colour discrimination task.ResultsChronic Amistar treatment did not impair the learning of the bees, but a statistically non-significant negative trend was observed in memory retention between the final learning bout and the subsequent memory test.ConclusionsThe results of our study suggest that chronic sublethal exposure to Amistar fungicide did not significantly impair the learning ability of bumblebees. However, there was a trend towards impaired memory retention, although this was not statistically significant. These findings provide further support for the hypothesis that Amistar may have a negative effect on bee cognitive performance. It is important to continue studying the effects of widely used pesticides on pollinators, as their decline is a complex issue with multiple contributing factors. Understanding the effects of different pesticide residue levels on bumblebees can inform policymakers in making more sustainable pesticide legislation and help protect pollinators.Peer reviewe

Oral exposure to thiacloprid-based pesticide (Calypso SC480) causes physical poisoning symptoms and impairs the cognitive abilities of bumble bees

Abstract Background: Pesticides are identified as one of the major reasons for the global pollinator decline. However, the sublethal effects of pesticide residue levels found in pollen and nectar on pollinators have been studied little. The aim of our research was to study whether oral exposure to the thiacloprid levels found in pollen and nectar affect the learning and long-term memory of bumble bees. We tested the effects of two exposure levels of thiacloprid-based pesticide (Calypso SC480) on buff-tailed bumble bee (Bombus terrestris) in laboratory utilizing a learning performance and memory tasks designed to be difficult enough to reveal large variations across the individuals. Results: The lower exposure level of the thiacloprid-based pesticide impaired the bees’ learning performance but not long-term memory compared to the untreated controls. The higher exposure level caused severe acute symptoms, due to which we were not able to test the learning and memory. Conclusions: Our results show that oral exposure to a thiacloprid-based pesticide, calculated based on residue levels found in pollen and nectar, not only causes sublethal effects but also acute lethal effects on bumble bees. Our study underlines an urgent demand for better understanding of pesticide residues in the environment, and of the effects of those residue levels on pollinators. These findings fill the gap in the existing knowledge and help the scientific community and policymakers to enhance the sustainable use of pesticides

Chronic oral exposure to Amistar fungicide does not significantly affect colour discrimination but may impact memory retention in bumblebees

Abstract Background: Intensive agriculture, including pesticides, is one of the many reasons for pollinator decline. The EU legislation on plant protection products (hereon pesticides) demands that the risks of active substances and their use in pesticide products are assessed for bees. However, the risk assessment is not always sufficient as shown, for example, in the case of the fungicide Amistar. The fungicide has been shown to cause lethal and sublethal effects on bumblebees at levels that, according to the EU risk assessment, do not require risk mitigation measures to protect bees. In order to understand the effects of chronic Amistar exposure on bumblebees, we studied whether 5 days of oral exposure to 0.015 µl Amistar (3.75 µg azoxystrobin/day) impairs bumblebees’ learning and memory performance in the 10-colour discrimination task. Results: Chronic Amistar treatment did not impair the learning of the bees, but a statistically non-significant negative trend was observed in memory retention between the final learning bout and the subsequent memory test. Conclusions: The results of our study suggest that chronic sublethal exposure to Amistar fungicide did not significantly impair the learning ability of bumblebees. However, there was a trend towards impaired memory retention, although this was not statistically significant. These findings provide further support for the hypothesis that Amistar may have a negative effect on bee cognitive performance. It is important to continue studying the effects of widely used pesticides on pollinators, as their decline is a complex issue with multiple contributing factors. Understanding the effects of different pesticide residue levels on bumblebees can inform policymakers in making more sustainable pesticide legislation and help protect pollinators

SpotIT – IT-solutions for user friendly IPM-tools in management of leaf spot diseases in barley and wheat

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