Ocena przydatności wskaźnika Fv/Fm we wczesnej detekcji odporności owsa głuchego (Avena fatua L.) na fenoksaprop i diklofop

The possibility of the chlorophyll α fluorescence test (maximum quantum efficiency of PS2 photochemistry - Fv/Fm parameter) in the early detection of wild oat resistance to fenoxaprop-P-ethyl and diclofop methyl was examined. Measurements were taken at two terms: 24 and 48 hours from spraying the resistant nad susceptible biotypes of weed with field doses of herbicides: Puma Uniwersal 069 EW and Illoxan 36 EC. The obtained results indicate, that chlorophyll fluorescence test can not be used for an early detection of wild oat (Avena fatua L.) resistance to tested herbicides.W pracy badano możliwość wykorzystania pomiaru fluorescencji chlorofilu α (maksymalna wydajność kwantowa fotoukładu 2 - parametr Fv/Fm) do wczesnego wykrywania odporności owsa głuchego na fenoksaprop-P-etylu i diklofop metylu. Pomiarów dokonywano w dwóch terminach: 24 i 48 godzin od oprysku biotypów chwastu (odpornych i wrażliwych) polowymi dawkami herbicydów Puma Uniwersal 069 EW oraz Illoxan 36 EC. Wykazano, że pomiar fluorescencji chlorofilu α w obu terminach nie może być podstawą do określenia odporności chwastu na badane herbicydy

Ocena oddziaływania chemicznej ochrony na zdrowotność liści i elementy plonowania bobu

The paper aimed at an evaluation of chemical protection means (Vitavax 200FS, Decis 2.5 EC, Fastac 100EC and Penncozeb 80 WP) effect on leaf healthiness of two broad bean cultivars (White Windsor and White Hangdown), and the elements of seed yield structure. Obtained results demonstrated that years significantly diversified intensity of fungal diseases on broad bean leaves and the elements of seed yield structure. Excessive moisture during vegetation period favours leaf infection by brown spot (B. fabae) and worsens the elements of seed yield structure. Broad bean leaves susceptibility to fungal diseases and seed structure elements depend on the cultivar. White Windsor cultivar, intended for early harvest is characterized by markedly greater sensitivity to fungal diseases and produces more seeds per pod with higher 1000 grain weight. Foliar application of chemical protection means, conducted three or four times (2 x insecticide +1 x fungicide or 3 x insecticide + 1 x fungicide) guarantees better health state of plants and favours increase in 1000 grain weight.Celem pracy była ocena wpływu środków chemicznej ochrony (Vitavax 200 FS, Decis 2,5 EC, Fstac 100 EC, Penncozeb 80 WP) na zdrowotność liści dwóch odmian bobu (Windsor Biały i Hangdown Biały) oraz elementy struktury plonu nasion. Uzyskane wyniki wykazały, że lata istotnie różnicują nasilenie chorób grzybowych na liściach bobu oraz elementy struktury plonu nasion. Nadmiar wilgoci w okresie wegetacji sprzyja wzrostowi porażenia liści przez czekoladową plamistość (B. fabae) i pogarsza elementy struktury plonu nasion. Podatność liści bobu na choroby grzybowe oraz elementy struktury plonu nasion zależą od odmiany. Odmiana bobu Windsor Biały przeznaczona na wczesny zbiór cechuje się istotnie większą wrażliwością na choroby grzybowe i wytwarza więcej nasion w strąku o większej masie 1000 nasion. Trzykrotna lub czterokrotna aplikacja nalistna środków chemicznej ochrony (2x insektycyd + 1x fungicyd lub 3 x insektycyd + 1x fungicyd) zapewnia lepszy stan zdrowotny roślin i sprzyja wzrostowi masy 1000 nasion bobu

Accumulation of H ₂ O ₂ and changes in activities of antioxidative enzymes and β -1,3-glucanase in barley and meadow fescue leaves attacked by Bipolaris sorokiniana

The effects of Bipolaris sorokiniana inoculation on accumulation of hydrogen peroxide and changes in the activities of superoxide dismutase (SOD), catalase (CAT), non-specific peroxidase (PX) and β -1,3-glucanase enzymes in leaves of differentially resistant spring barley and meadow fescue were investigated in this study. Hydrogen peroxide accumulated slightly in inoculated barley leaves 24 hours after inoculation, and its accumulation after 48 hours of pathogenesis remained week around sites of infection. In leaves of fescue, which is more resistant to B. sorokiniana , accumulation of H 2 O 2 was faster and stronger in comparison to barley. A slight increase in SOD activity was observed only in infected fescue. Catalase activity in infected barely leaves decreased significantly 48 hours after inoculation, while in fescue-infected plants CAT activity, following a slight decrease, remained similar to the control values. PX activity was considerable lower in inoculated barley leaves after 6 hours, but at 24 and 48 hours after inoculation its activity increased significantly compared to the control. In inoculated fescue leaves activity of PX was higher at 6 and 24 hours compared to the control, while at 48 hours PX activity was strongly inhibited. β -1,3-Glucanase activity in inoculated barley plants did not differ from that of the control, while in infected fescue leaves it increased significantly 48 hours after inoculation. Based on the results, we suggest that the strong accumulation of H 2 O 2 , changes in antioxidant levels, together with the significant increase of β -1,3-Glucanase activity in infected fescue leaves, plays an important role in fescue’s greater resistance to B. sorokiniana

Progesterone moderates damage in Arabidopsis thaliana caused by infection with Pseudomonas syringae or P. fluorescens

Brassinosteroids are known to protect plants against various abiotic and biotic stresses, however, very limited information is available about the role of progesterone. Therefore the effects of Pseudomonas syringae pv. syringae (P.s.) wild type strain 61, its hrcC mutant, and the saprophytic P. fluorescens (P.f.) strain 55 were investigated in wild type Arabidopsis thaliana cv. Columbia and its rbohF knock-out mutant with and without progesterone pre-treatment. The reactions of wild type and rbohF mutant Arabidopsis to bacterial inoculations were similar although 2 h after injection of P.s. a larger increase of electrolyte leakage was measured in wild type than in rbohF knockout mutant leaves. The hrcC mutant caused weak necrotic symptoms and increased leakage in both types of Arabidopsis although to a much lesser extent than P.s. The P.f. did not induce any visible symptom but slightly increased the electrolyte leakage in both types of Arabidopsis. Inoculation by all Pseudomonas bacteria led to significant alterations in photosystem II efficiency as compared to control plants. Pre-treatment of leaves with progesterone diminished the necrotic symptoms, the electrolyte leakage and improve the efficiency of photosystem II caused by Pseudomonas bacteria