We determined the chlorophyll a and b levels (SPAD readings) in uninfested leaves and in leaves after 7 and 17 days of aphid infestation in four Fabaceae species (Pisum sativum L., Vicia faba L., Trifolium pretense L, Medicago sativa L.). Feeding by pea aphids Acyrthosiphon pisum Harris (Hemiptera: Aphididae) caused significant loss of chlorophyll a and b in the infested plants. Uninfested leaves on both short-and long-infestation plants had significantly higher chlorophyll a and b than infested leaves.K Ke ey y w wo or rd ds s: : chlorophyll a+b, Fabaceae, Acyrthosiphon pisum, SPAD values.

No abstract

The objective of performed study was aimed at evaluating the antifungal potential of four extract fractions (methanolic, ethyl acetate, alkaloid, and hydrolyzed methanolic) derived from Juglans regia (L.) leaves against pathogenic Candida albicans strains. Furthermore, total phenolics and alkaloid content as well as the antioxidative potential of examined extract fractions were determined. Tested yeasts comprised 140 isolates from diverse biological specimens (oropharyngeal, rectal and vulvovaginal swabs, skin lesions, sputum, urine, and faeces), and one reference strain (C. albicans ATCC 90029). Methanolic extract from walnut leaves characterized by the highest anticandidal activity, the alkaloid fraction possessed a slightly lower antifungal efficacy, while ethyl acetate and hydrolyzed methanolic preparates inhibited the growth rate of examined fungal pathogens in the lowest degree. Additionally, it has been elucidated that all tested strains were susceptible for nystatin and amphotericin B, and only one yeast strain was resistant to flucytosine. On the contrary, the group of azole antimycotics were characterized by reduced effectiveness against the candidal isolates.

We measured the total chlorophyll (Chl a+b) content in seedling leaves of fifteen maize cultivars infested by two studied aphid species (oligophagous Rhopalosiphum padi L., monophagous Sitobion avenae F.) 7 and 14 days after the beginning of infestation, using a SPAD-502 chlorophyll meter. Chlorophyll loss was more severe in R. padi-infested than in S. avenae-infested plants. Chlorophyll depletion was greater after long-term (14 days) than after short-term aphid infestation in the investigated host systems. Seedlings of Złota Karłowa and Tasty Sweet were more damaged by aphid feeding; Ambrozja and Płomyk plants were less damaged by aphid feeding.K Ke ey y w wo or rd ds s: : Total chlorophyll (Chl a+b) content, SPAD units, maize, Rhopalosiphum padi, Sitobion avenae.

Rośliny przeciwdziałają skutkom ataku roślinożerców za pomocą różnych mechanizmów morfologicznychi biochemicznych. W odpowiedzi na uszkodzenia, rośliny wytwarzają związki obronne, wpływające na żerowanie i zachowanie roślinożerców. Ponadto rośliny uwalniają również VOCs, które przyciągają naturalnych wrogów roślinożerców. Po zasiedleniu roślin przez owady, w dalszym ciągu zachodzą kompleksowe oddziaływania w strategii obronnej roślin przed roślinożercami. Poza emitowaniem VOCs, znaczny wpływ wywierają dodatkowo roślinne allelozwiązki, takie jak związki fenolowe i kwasy hydroksamowe.