RAPD Marker for Resistance Against Heterodera cajani in Wild Pigeon Pea Accessions

Pigeon pea cyst nematode, Heterodera cajani, is an important nematode problem in majority of the pigeon pea growing areas of India, particularly on the black cotton soils in the southern and western India. Resistant varieties have so far not been developed for the management of this nematode. Three nematode resistant accessions ICPW 543, ICPW 544 and ICPW 545 of Cajanus platycarpus were compared with the susceptible accessions ICPW 63 and ICPL 87 by randomly amplified polymorphic DNA analysis to identify a RAPD marker for nematode resistance. Forty one Operon decamer oligonucleotides were tested to determine the genetic variability leading to the identification of a RAPD marker specific to resistant accession. In general, very low level of polymorphism was observed. This could be due to fact that in nature, legumes exhibit very low amount of genetic variability. Four RAPD primers OPB 3, 4, 6 and 7 amplified fragments of different sizes only in the resistant accessions of C. platycarpus. Approximately 1550 and 850 base pair RAPD fragments were amplified by the primers OPB 3 and 7, respectively in all the resistant accessions. Primers OPB 4 amplified a fragment of 450 bp only in ICPW 544, while, OPB 6 gave a 750-bp fragment in ICPW 544 and ICPW 545. Further, sequence characterization of these markers will be useful for marker assisted breeding program while developing resistant varieties for pigeon pea cyst nematode management.