Reaction of various citrus root stocks (germplasm) against citrus root nematode (Tylenchulus semipenetrans Cobb.)

Thirteen root stocks of citrus were evaluated to identify genetic sources of resistance against citrus nematode (Tylenchulus semipenetrans Cobb.). Out of 13 root stocks 3 root stocks were resistant, 2 moderately resistant, 3 moderately susceptible and 5 were susceptible. Carrizo citrang, Citromela and Grape fruit were resistant. Sachton citrumelo and Savageage citrange were moderately resistant and Gadi Dahi, Yuma citrange and Kharana khata were moderately susceptible, whereas, root stocks of Bitter sweet orange, Brazilian sour orange, Sour orange, Chakotra, Rough lemon, were found to be susceptible. The resistant genotypes could be used in future breeding programs for the development of nematode resistant rootstocks.