Molecular characterisation and genetic diversity analysis of Populus deltoides Bartr. ex Marsh. clones using SSR markers

摘要

In India, only few poplar clones are commercially grown over the vast tracts of land. This practice of monoculture is alarming as outbreak of any disease or pest incidence may wipe out the whole plantations of narrow genetic base. A study was carried out to find out genetic diversity among the 147 poplar clones. Of 32 simple sequence repeat (SSR) markers used in study, only 22 markers showed polymorphic pattern and amplified a total of 102 alleles. Average number of alleles amplified per locus was 4.5. Two unique alleles specific to 65/27 and one allele specific to U64c were also detected. The polymorphism information content (PIC) value at a locus ranged from 0.29 to 0.77. The results demonstrated that the PTR SSR DNA-markers developed from P. tremuloides and WPMS SSR markers established from P. nigra could be successfully used to differentiate genotypes of P. deltoides. Cluster analysis of SSR data using UPGMA separated 147 clones into 6 major clusters at similarity coefficient of 0.60. The diverse clones identified in the study would be useful for developing intraspecific hybrids to exploit hybrid vigour and for commercial cultivation to broaden genetic base. The DNA fingerprints obtained for each clone can be used for biodiversity conservation.