darjeeling tea may soon have its characteristic aroma patented. The Centre for dna Fingerprinting and Diagnostics (cdfd), Hyderabad, is soon starting a project to develop molecular markers, which will distinguish this world famous variety from its cheaper cousins and protect its market value. The Union ministry of commerce has recently asked cdfd to develop a genetic protocol for Darjeeling tea on the lines of the one developed for basmati rice.

The proposed project may prove a shot in the arm for Indian exporters to authenticate Darjeeling tea as in the case of basmati. Exporters of traditional basmati varieties are already vying to apply the technique to authenticate their product. Recently, United Riceland, one of the biggest exporters of traditional basmati rice from India has sought help from cdfd to certify its variety by using the genetic marker system. T he technique developed by cdfd promises to detect adulteration even up to 0.75 per cent in basmati. It was developed after the cdfd team, headed by J Nagaraju, studied 24 rice varieties from a subset of three rice groups of traditional basmati (tb), evolved basmati (eb) and semi-dwarf non-basmati (nb).

The scientists used two classes of dna markers for the purpose of carrying out genetic analysis of the rice varieties. The first class of marker is helpful in detecting the degree of polymorphism (a variation in the sequence of dna among a set of individuals) while the other one helps to fingerprint the rice variety.

After the selection of primers and conducting marker survey, the scientists carried out evaluation of polymorphism and an analysis of genetic diversity. Both the extent of polymorphism and genetic diversity were calculated for each of the selected primers in all the three rice groups.

The study determined that the degree of polymorphism