Morphological and molecular characterization of guava

Abstract

To characterize 20 genotypes of Psidium spp., observations were recorded for leaf blade length and width, petiole length, vein number, leaf surface area, leaf shape, leaf apex and base shape, upper and lower leaf surface colour, leaves colour during winters, leaf texture, pubescence and leaf lamina thickness which revealed significant variations among genotypes. Psidium chinensis was most diverse morphologically. Out of 20 decamer RAPD primers used four primers generated strong amplifications and resulted in polymorphic products; these were viz., OPA-03, OPA-05, OPS-04 and OPS-08. Percent polymorphism was 97.43% having a range of 87.5% to 100%. The average number of scoreable bands per primer was 9.75, while average number of polymorphic bands was 9.5. High polymorphism frequency was detected with all the selected primers. The similarity coefficient ranged from 0.42-0.83. The study showed that the genetic base of Indian guava can be rated as moderate to high diversity.