Biochemical and molecular diversity assessment of Pandanus amaryllifolius Roxb. populations from India and its molecular characterization for BADH

Pandanus amaryllifolius, is the best available natural source of principal basmati aroma compound 2 acetyl-1-pyrroline (2AP) and hence used widely to flavour various food dishes in south-east Asian countries. In this species, lower epidermal papillae have been identified as a site of 2AP storage and its detailed SEM study has been carried out. Populations of P. amaryllifolius were collected from 37 localities of East and West coast of India, analyzed for 2AP and other aroma volatiles using head space solid phase micro extraction (HS-SPME) coupled with GC-MS/GC-FID and an elite population containing 12.24 ppm 2AP has been identified from Palghar locality of Maharashtra. Genetic diversity of collected populations was assessed using ISSR and AFLP markers. The study revealed less than 3 % genetic variability confirming that the species has very low level of genetic variation and the genome is highly conserved. In order to address the high level of 2AP expression, it was further attempted to characterize BADH2 enzyme from leaves of P. amaryllifolius. BADH enzyme activity was found to be 0.169 micro mol/min in P. amaryllifolius. Partial cDNA based sequence of BADH gene was obtained that showed more than 85% homology with the rice BADH2. By southern blot analysis two BADH isoforms were also detected. Thus, the study suggests similar kind of 2AP synthesis mechanism, as found in scented rice, might exist in P. amaryllifolius. Further studies in this species are being made to reveal the mechanism of high levels of 2AP biosynthesis.