Microscopic and ultrastructural studies of grape cultivars (Vitis vinifera L.) with variable susceptibilities to anthracnose

The present studies were conducted to decipher structural traits of grape varieties associated with resistance to anthracnose. Vines of grape varieties viz., Perlette, Pusa Navrang, Beauty Seedless, Flame Seedless and H 516 (Punjab MACS Purple) grown at the Research Farm of Department of Fruit Science, Punjab Agricultural University, Ludhiana were screened for resistance and susceptibility to anthracnose. The variety H 516 having Percent disease index (PDI) 1.66 was categorised as resistant to anthracnose, whereas Perlette was rated as susceptible with PDI of 73.00. The stomatal length, width and stomatal index were significantly high in the most susceptible variety Perlette as compared to the rest of the varieties. Transverse section of leaves of H 516 indicated presence of highly compact spongy mesophyll and trichomes conferring resistance.