Further Studies on the Existence of Races in Pigeon Pea Cyst Nematode, Heterodera Cajani

Seven populations of Heterodera cajani viz., Ambala, Faridabad, Bhiwani (Haryana); Ludhiana (Punjab); Delhi; Coimbatore (Tamil Nadu); and Hyderabad (Andhra Pradesh) were tested on four host differentials namely—cluster bean, sunhemp, sesame and pigeon pea. Six populations (designated as race A) did not multiply on cluster bean and sunhemp, only Bhiwani population multiplied on them thus constituting a different race (designated as race B). The results on sesame were inconclusive. The possibility of existence of more than two races is not ruled out.