Distribution and DNA profiling of Cycas beddomei Dyer. : A critical endangered gymnosperm.

Abstract

Abstract Cycas beddomei is a  critically endangered plant species belonging to the cycadales of the  gymnosperm under family Cycadaceae grown in the hill slopes and grassy woodland forest. It is considered as a living fossil, as its distribution is very rare, though it flourished well in the Mesozoic era. No report on molecular profiling and genetic distribution on Cycas beddomei for conservation and multiplication Molecular marker like Inter Simple Sequence Repeats (ISSRs) markers were used to identify the species with genetic analysis among the individuals collected from wild populations of the state of Andhra Pradesh, India. It is only growing in the hill regions of the state of Andhra Pradesh, India. Among the twenty ISSR primers tested, only fifteen of them produced unambiguous DNA fragments through polymerase chain reaction. All the clones of Cycas beddomei extensively amplified using these fifteen ISSR primers and produced a total of 86 fragments ranging from 300 bp to 2500 bp. The maximum number of polymorphic markers and percentage of polymorphism were 70 and 81.3 respectively. Average number of polymorphic ISSR marker was 4.7. The average PIC value, reflecting the expected heterozygosity, was 0.749 and the frequency for the ISSR loci ranged from 0.623 - 0.914. The dendrogram generated based on ISSR markers showed distinct clusters. The six clones were clearly separated into two major clusters with 50% similarity. The variation due to the biological regeneration of the species. There is an urgent need to take effective measures to protect this critically endangered species against further loss of genetic diversity and for ex situ conservation.