Identification of genetic redundancy in mulberry germplasm assembled for screening diseases and pest resistance by DNA marker aided analysis.

摘要

A close examination of the morphological features of the germplasm assembled for their contrasting response (resistance and susceptibility) to powdery mildew, root knot nematode and mealy bug infestation in mulberry indicated the presence of 10 groups of redundant collections. DNA marker profiling of germplasm was carried out using 16 informative random primers which amplified a total of 209 markers with 87% polymorphism. DNA marker similarity coefficient (s) ranged from a maximum of 1.000 to a minimum of 0.564. Unweighted Pair Group Method of Arithmetic Average (UPGMA) clustering of germplasm using marker similarity matrix confirmed duplicate status of collections in the groups I, III, V, VI, VII, and VIII. However, in suspected redundant group II, the germplasm collection namely, Calabrassa had a unique profile and separated from the rest two with a genetic distance (1-s) of 0.267. The largest suspected redundant group IV comprised of 10 germplasm of which 4 collections had unique banding patterns and thus discriminated. Rest of the collections in the group was redundant. In the suspected group IX, Jatinuni had distinct banding pattern and separated from the other two accessions in the group. The other redundant collections viz., Viswa and Araku Local formed one cluster with 100% similarity. The two collections of the last suspected redundant group X were distinct. Minimum genetic redundancy is the key to the success of crop evaluation and biodiversity management by cutting down the physical and financial resources.