Effect of Phytophthora drechsleri f. sp cajani infection on local pigeon pea variety of Gujarat

Pigeon pea (Cajanus cajan L), is a perennial crop plant of arid and semiarid regions and its growth has been affected by many biotic stresses and phytophthora blight is one of them. Phytophthora drechsleri f. sp cajani is a causative agent of phytophthora blight disease in pigeon pea. The morphological, anatomical, and biochemical analysis of two local pigeon pea varieties Shrawani and Shweta for phytophthora infection was assayed in this study. The morphological investigation showed that the infection significantly decreased root length; shoot length, number of leaves, fresh weight, and dry weight by 0.5–2 fold in the Shrawani variety, compared to Shweta. In anatomical analysis, infected Shrawani especially showed signs of cellular damage and mycelial invasion, but the infected Shweta variety showed no symptom of fungal development in another part of the plant except in the roots by the 20th day of infection. The results of the biochemical analysis were related to the morphological and anatomical analysis. These results highlight the strong defensive mechanisms in Shweta, which was characterized by prolonged biochemical responses and enhanced lignification. These findings propose a piece of critical valuable information for screening pigeon pea varieties for resistance toward phytophthora.