Evaluation of the Growth, Sporulation, Fungicide Efficacy, and Host Range of Ramularia sphaeroidea

TL;DR

This study evaluates the growth, sporulation, fungicide effectiveness, and host range of Ramularia sphaeroidea, a fungus causing leaf spot disease in hairy vetch.

Contribution

The study identifies optimal conditions for sporulation and effective fungicides, and reveals a broader host range for R. sphaeroidea.

Findings

Oatmeal, maltose, and potassium nitrate agar supported the highest sporulation of R. sphaeroidea.

Difenoconazole (10%) was the most effective fungicide against R. sphaeroidea-induced leaf disease.

R. sphaeroidea infected six plant species, showing a wider host range than previously known.

Abstract

Ramularia sphaeroidea was primarily identified based on the characteristics of its conidia and several sequences. The fungus causes severe leaf spot disease on hairy vetch (Vicia villosa var. glabrescens) in Yunnan Province in China. The growth, sporulation, fungicide efficacy, and host range of the pathogen were evaluated to aid in disease management. Different types of culture media and carbon and nitrogen sources were used to evaluate the growth of R. sphaeroidea. Oatmeal, maltose, and potassium nitrate agar had a higher amount of sporulation. Difenoconazole (10%) was the most effective fungicide against the leaf disease caused by R. sphaeroidea. In addition, foliar inoculation sprays were used to assess the host range of R. sphaeroidea in six different plant species, including alfalfa (Medicago sativa L.), sainfoin (Onobrychis viciifolia Scop.), erect milkvetch (Astragalus adsurgens Pall.), common vetch (Vicia sativa L.), red clover (Trifolium pratense L.), and white clover (Trifolium repens L.). R. sphaeroidea successfully infected these plants, indicating that it has a wider host range than hairy vetches.

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