Molecular characterization of wilt resistant and susceptible genotypes of <italic>Cajanus cajan</italic> (L.)

Abstract

Characterization of germplasm is important for breeding programme. Therefore, in present investigation 9 genotypes of pigeonpea [<italic>Cajanuscajan</italic> (L) Millsp] comprising three wilt resistant genotypes (Vaishali, ICPL 87119 and national check ICP 8863) and two susceptible genotypes (T<sub>15-15</sub> and national check ICP 2376) along with four other popular genotypes grown in Gujarat, India (BDN-2, GT-100, GT-102 and C-11) were characterized using RAPD, ISSR and SSR markers. Genetic diversity of 9 pigeonpea genotypes revealed an average polymorphism of 39.18% by RAPD, 47.67 % by ISSR and 57.35 % by SSR. On the basis of polymorphism (%), PIC(polymorphic information content) value, MI (Marker index) value primer OPI-12 was found most informative among 12 RAPD primers. While ISSR primer UBC-850 was found most informative among 8 ISSR primers showing 80% polymorphism, 0.51 PIC value and 40.80 MI value. SSR primers gave 2 to 5 amplicon on a 6 % polyacrylamide gel. The average PIC value was 0.36, ranging from 0 to 0.73. PIC also provides the estimate of discriminatory power of a locus in the case of SSR marker system by taking into account not only the number of alleles expressed, but also the relative frequency of those alleles. Our prime target of discrimination between wilt resistant and susceptible genotypes of pigeon pea was achieved by ISSR and SSR markers. However, SSR was more efficient in generation of polymorphism among the genotypes based on the information on the level of polymorphism and the PIC value.