Mycopathologia

, Volume 114, Issue 1, pp 29–34 | Cite as

Pathogenesis of barley leaves by Helminthosporium teres II: Carbohydrate involvement

  • Renu Angra
  • C. L. Mandahar
Article

Abstract

Conidia of Helminthosporium teres had negligible difference in germination and germ tube length between the decolorized and non-decolorized host leaves. Appressoria, penetration and colonization were less on decolorized host leaves, but addition of exogenous nutrients stimulated these stages. Leached conidia had reduced germination on decolorized host leaves, while appressoria formation, penetration and colonization were negligible. The addition of nutrients in the external environment, however, enabled some of the leached conidia to penetrate and colonize. Stimulation by the exogenous nutrients in decreasing order were: sucrose > glucose > yeast extract > leaf leachates. Optimum levels for various nutrients tested were 2% (w/v) each of sucrose and glucose, and 0.1% (w/v) yeast extract. Higher concentrations inhibited these stages of infection. Leached conidia and decolorized leaves had smaller amounts of carbohydrates than non-leached conidia and non-decolorized leaves, respectively. Depletion of host carbohydrates reduced appressoria formation, penetration and colonization and loss of carbohydrates from spores reduced germination.

Key words

Helminthosporium teres Hordeum vulgare carbohydrates leached/non-leached spores decolorized-non-decolorized leaves 

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Copyright information

© Kluwer Academic Publishers 1991

Authors and Affiliations

  • Renu Angra
    • 1
  • C. L. Mandahar
    • 1
  1. 1.Department of BotanyPunjab UniversityChandigarhIndia

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