Phytophthora infestans Culture Media: A Comparative Study of Cost-Effective V8 Agar and Rye Agar

Abstract

Phytophthora infestans is a pathogen that causes late blight in crops, such as potatoes and tomatoes, posing a serious threat to the Solanaceae family. Researchers have attempted to create an affordable and effective medium for isolating and cultivating this pathogen. The aim of this study was to evaluate the efficacy of low-cost V-8 agar for mycelial growth, sporangia production, and oospore production of P. infestans and compare it with Rye A medium. To achieve this, V-8 medium was modified by replacing V-8 juice with tomato. Mycelial growth and sporulation were measured on both media after 14 days of inoculation. It was observed as a white, fluffy growth in both media. The mean radial growth was larger on the low-cost V-8 medium (76 mm) than on Rye A medium (4.4 mm). The lemon-shaped sporangia with a semipapilated structure were recorded with an average length-to-width ratio of 28.6 μm to 30.6 μm, respectively. Oospore production was greater in the low-cost V-8 medium (5x10⁴) than in Rye A medium (1x10⁴). The present study demonstrated that low-cost, locally available materials such as tomato can be used as an alternative nutrient medium for the growth of P. infestans.