Doświadczenia prowadzono w hali wegetacyjnej metodą kultur wazonowych. Glin do podłoża wprowadzano w formie Al2(S04)3 lub A1C13 w następujących ilościach na wazon: 0, 5, 10, 20 mg ■ L-1. Pozostałe składniki mineralne podano według wymagań pokarmowych sałaty. Rośliny zbierano po 2, 4 i 6 tygodniach wegetacji. Po zbiorze roślin określono suchą masę części nadziemnych i korzeni, w której oznaczono zawartość magnezu. Na podstawie uzyskanych wyników obliczono zmiany w tempie akumulacji magnezu w sałacie. Występujące w czasie wegetacji roślin zależności między dawką i formą glinu wpłynęły istotnie nie tylko na akumulację magnezu w sałacie, ale także na jej produktywność. Po zastosowaniu glinu w formie chlorku nastąpił wyraźny spadek plonu we wszystkich kombinacjach. W przypadku zaś stosowania glinu w formie siarczanu obniżkę plonu zaobserwowano przy stosowaniu dwóch najwyższych dawek (10 i 20 mg • L-1). Natmiast na glebie z 5 mg ■ L-1 glinu wystąpił wzrost plonu sałaty w stosunku do obiektu kontrolnego. W tych warunkach stwierdzono także korzystny wpływ glinu na pobieranie magnezu przez korzenie sałaty, o czym świadczy wartość wskaźnika Rr. Najwyższą jego wartość uzyskano u 4-tygodniowych roślin rosnących na glebie z najniższą dawką glinu podanego w formie A12(S04)3. W pozostałych zaś seriach żywieniowych wartości tego wskaźnika były niższe w porównaniu z obiektem kontrolnym.
The objective of the research was to examine an effect of Al stress appearing under conditions of differentiated NPK fertilization on carbohydrate and ascorbic acid contents in radish thickenings. The relations between aluminium content and nitrogen, phosphorus and potassium concentration in the substrate observed throughout plant vegetation season affected carbohydrate and ascorbic acid contents in radish thickenings. It was proved that with growth of Al the contents decrease of both compounds decreased. This drop was noted more clearly at a single NPK dose application. However, a double dose of nitrogen, phosphorus and potassium partly neutralized unfavourable effect on the plants. It was manifested by higher contents of ascorbic acid and carbohydrates in radish thickenings.
The influence of aphid feeding on chlorophyll a fluorescence in the leaves of four cultivated hazel cultivars, with different levels of resistance to filbert aphid (Myzocallis coryli Goetze), was studied. The maximum effect of photosystem reaction measured on dark-adapted hazel leaves (Fv/Fm parameter) and maximum efficiency of photon energy PAR conversion to chemical energy in light conditions (Y parameter) were estimated twice, in the leaves of four hazel cultivars with different levels of resistance to filbert aphid, using a fluorometer PAM- 2000 by Walz GmbH – Germany. The analysis of changes of these parameters showed that aphid feeding caused a reaction in all tested cultivars. The most visible reduction of the Fv/Fm and Y values as a result of aphid feeding was observed in the cultivars ‘Cud z Bollwiller’ and ‘Olbrzymi z Halle’, numerously colonized by aphids. A smaller number of aphids found on the leaves of more resistant cultivars – ‘Kataloński’ and ‘Lamberta Biały’, caused a weaker response of plants and a smaller decline in the value of this parameter. ‘Cud z Bollwiller’ cultivar showed higher tolerance than other tested cultivars to stress caused by the feeding of sucking insects. The Fv/Fm and Y parameters can be regarded as reliable indexes useful in diagnosing susceptibility of hazel cultivars to aphids, helpful in determining, for example, harmfulness thresholds.
W przeprowadzonym doświadczeniu badano wpływ dawki potasu i regulatorów wzrostu na jakość liści sałaty przechowywanej przez 6 dni w temperaturze 5°C. Sałatą szklarniową odm. Ambra uprawiano metodą kultur wazonowych w mieszaninie ziemi ogrodniczej i piasku (5 : 1), w warunkach fitotronu, przez 6 tygodni. W żywieniu roślin zastosowano trzy rodzaje pożywki mineralnej różniącej się między sobą dawką potasu. Regulatory wzrostu - benzyloadeninę lub sperminę zastosowano dolistnie 2 dni przed zbiorem. Uzyskane wyniki wskazują, że jakość liści sałaty świeżej i przechowywanej zależała od dawki potasu, jak również od zastosowanych regulatorów wzrostu. Na ogół regulatory wzrostu wpływały na obniżenie zawartości azotanów i azotynów w przechowywanych liściach sałaty. Benzyloadenina i spermina obniżały zawartość sumy fenoli przy najniższym i najwyższym poziomie potasu - tylko w porównaniu do prób świeżych. W porównaniu do prób przechowywanych (K II) tylko przy K₂.
A study was conducted to investigate the ability of arbuscular mycorrhizal fungi (AMF) in enhancing the growth and control of a root rot caused by different isolates of Fusarium oxysporum in sweet pepper seedlings. The plants were grown in plastic pots filled with sterilized horticultural soils. There were four treatments applied as follows: Fo (seedlings infected with fungus), M (seedlings inoculated with mycorrhizal fungi), Fo + M (seedlings inoculated with mycorrhiza and infected with fungus) and control. A randomized experiment was used and the growth, disease index, and photosynthetic activity of the plants were measured after 4 weeks. The investigations showed that the mycorrhizal inoculation had a protective effect on the F. oxysporum-infected pepper seedlings. The plants were characterized by a higher growth rate and a lower disease index than those growing only in the presence of the pathogenic fungus. The roots inoculated with mycorrhizal fungi were better developed than those infected only with F. oxysporum. The mycorrhiza contributed to an increase in the photosynthetic activity of the pepper seedlings.
Analysis of changes in chlorophyll fluorescence parameters in strawberry leaves was based on a field experiment performed in the years 2009–2010. Ten genotypes including 5 cultivars: ‘Kent’, ‘Teresa’, ‘Senga Sengana’, ‘Chandler’ and the breeding clone 1387 as well as their inbred progeny, were the object of the study. During the experiment the following indicators were evaluated: chlorophyll a and b content in fresh leaf mass as well as fluorescence parameters: minimum (F0) and maximum fluorescence yield (Fm), photochemical efficiency of PS II (Fv/Fm), actual quantum yield of PSII photochemistry (Y), minimum (F0’) and maximum efficiency of fluorescence (Fm’) in the light, coefficient of photochemical (qP) and non-photochemical (qN) fluorescence quenching. In this work, we also examined the effect of repeated inbreeding on strawberry fruit yield and yield components. The analysis of changes of these parameters showed that inbreeding caused a reaction in all tested cultivars. In all inbred progeny, chlorophyll a and b content decreased compared to the cultivars. Generally, the photochemical efficiency of photosystem II (Fv/Fm) and the parameter ?F/ Fm’ were not affected by strong inbreeding. In analyzing the values of the coefficients qP and qN, it has been observed that changes in their values depend on the sensitivity of the examined genotypes to self-pollination. The functioning of PS II is the most sensitive indicator of the effect of various factors on plants and is useful, among others, in breeding to select plants with a required genotype. The yield – determining features such as: fruit yield per plant, weight of single fruit, number of fruit per plant and weight of leaves per plant in S3 generation, were lower as compared with parental forms.
The analysis of photosynthetic activity ofHelianthus tuberosusleaves was based on thefield experiment carried out in 2003-2005 in The Experimental Station in Parczew on good ryecomplex soil. The experiment was performed by means of randomized sub-blocks in 3 replications,including factors: the 1st order - varieties(Albik and Rubik), and the 2nd order – mineral fertilizationat rates of: N₀P₀K₀, N₀P₄₄K₁₂₅; N₅₀P₄₄K₁₂₅; N₁₀₀P₄₄K₁₂₅; N₁₅₀P₄₄K₁₂₅; N₂₀₀P₄₄K₁₂₅, recalculated ontothe elemental forms on a background of full rate of FYM (30 t ha⁻¹). The plant’s photosyntheticactivity during flowering was evaluated by means of leaf chlorophyll fluorescence inductionmeasurements applyingPAM-2000 device. Following fluorescence parameters were determined:maximum efficiency of a photosystem PS II (FV/Fm), current number of electrons transported in PS IIunder conditions of light adaptationФPSII; efficiency of open units PS II – FV’/Fm’; coefficient ofphotochemical (qP) and non-photochemical fluorescence quenching (qN). It was found thatmaximum efficiency of the photosystem PS II (Fv/Fm) was the most stable chlorophyll fluorescenceindicator forHelianthus tuberosus, while coefficient of non-photochemical fluorescence quenching(qN) – the most changeable. Rubik cv. appeared to be the variety having higher values of Fv/Fm,ФPSII,qP, and qN, as well as their better stability, than Albik cv. Mineral fertilization applied atHelianthustuberosuscultivation contributed to the decrease of primary photosynthetic reactions in photosystemII (Fv/Fm) and disturbances of the efficiency of open units PS II (Fv’/Fm’). The decrease ofchlorophyll quantum efficiency (ФPSII), photochemical chlorophyll fluorescence quenching, andnon-photochemical chlorophyll fluorescence quenching (qN) were also observed.
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