Wyniki wyszukiwania

Filtruj wyniki

  • Czasopisma
  • Autorzy
  • Słowa kluczowe
  • Data
  • Typ

Wyniki wyszukiwania

Wyników: 3
Wyników na stronie: 25 50 75
Sortuj wg:

Abstrakt

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.
Przejdź do artykułu

Abstrakt

We studied the effect of qualitative and quantitative variation of saponin content in foliar tissues of four European alfalfa (Medicago sativa L.) cultivars (Radius, Sapko, Sitel, Radius line 1) on pea aphid (Acyrthosiphon pisum Harris) development, and the effect of aphid infestation on alfalfa saponin content. Aphids (adult apterae, larvae, and adult alatae) were counted on 3-, 6- and 9-month-old plants (before the first, second and third cutting). Thin-layer chromatography was used to detect and estimate the quantity of the following saponins: 3GlcA, 28AraRhaXyl medicagenic acid; 3Glc, 23Ara, 28AraRhaXylApi zanhic acid (zanhic acid tridesmoside); and 3RhaGalGlcA soyasapogenol B (soyasaponin I). Radius, Sapko, and Sitel contained all three saponins but Radius line 1 did not contain zanhic acid tridesmoside or medicagenic acid glycoside. Saponin content was highest in Radius and lowest in Radius line 1. Regardless of the cultivar, saponin content was higher in aphid-infested than uninfested plants. For all sampling dates, aphid numbers were highest on Radius line 1 and lowest on Radius; that is, aphid numbers were inversely related to saponin content. Alfalfa has a herbivoreinduced defense. Saponin levels increase in the foliage of infested alfalfa. Attempts of plant breeders to reduce saponin content in order to increase alfalfa digestibility for livestock might make the plants more susceptible to aphids and other pests.
Przejdź do artykułu

Abstrakt

Abstract The objective of the study was to assess the influence of methyl jasmonate (MJ) vapors on accumulation of 2-phenylethylamine (PEA), phenylacetic acid (PAA) and 2-phenylethanol (PE) in leaves and roots of maize (Zea mays L. subsp. mays, saccharata group, cv. Złota Karłowa) seedlings. Furthermore, we analyzed the expression patterns of eight genes (ADH1, ADH2, AO2, CAO, PDC1, PDC2, PTA and LOX, encoding alcohol dehydrogenase 1 and 2, primary amine oxidase, aldehyde oxidase 2, phenylalanine decarboxylase 1 and 2, phenylalanine (histidine) transaminase and lipoxygenase, respectively) involved in biosynthesis and turnover of PEA in maize tissues. In addition, the effect of MJ application on fresh biomass and growth of the tested seedlings was recorded. One-day MJ exposure increased the fresh weight of aerial parts and roots of Z. mays seedlings, whereas the opposite tendency occurred after 4-day of MJ treatment. One-day application of MJ resulted in an increase in the length of roots and its fluctuations in the aerial parts of maize plants, but extended exposure declined the growth of both parts of the seedlings. Methyl jasmonate elicitation caused various changes in the contents of PEA, PAA and PE in the maize seedlings. MJ treatments led to high upregulation of most genes, with the exception of three genes (i.e., ADH1, ADH2 and AO2) whose expression was downregulated after a 4-day exposure.
Przejdź do artykułu

Ta strona wykorzystuje pliki 'cookies'. Więcej informacji