Assessment of organochlorine pesticide residues in Indian flue-cured tobacco with gas chromatography-single quadrupole mass spectrometer.

Presence of pesticide residues in tobacco increases health risk of both active and passive smokers, apart from the imminent potential health problems associated with it. Thus, monitoring of pesticide residue is an important issue in terms of formulating stringent policies, enabling global trade and safeguarding the consumer's safety. In this study, a gas chromatography-single quadrupole mass spectrometry (GC-MS) method based upon quantifier-qualifier ions (m/z) ratio was employed for detecting and assessing ten organochlorine pesticide residues (α-HCH, ß-HCH, γ-HCH, δ-HCH, 2,4-DDT, 4,4-DDT, endrin, α-endosulfan, ß-endosulfan and endosulfan sulphate) in 152 flue-cured (FC) tobacco leave samples from two major tobacco growing states, Karnataka and Andhra Pradesh, of India. In the majority of samples, pesticide residue levels were below the limit of quantification (LOQ). In few samples, pesticide residues were detected and they found to comply with the guidance residue levels (GRL) specifications of the Cooperation Center for Scientific Research Relative to Tobacco (CORESTA). Detection of the phase out pesticides like DDT/HCH might be due to transfer of persistent residues from the environmental components to the plant. This is the first report on these ten organochlorine pesticide residues in Indian FC tobacco.

Molecular diversity in the genus Nicotiana as revealed by randomly amplified polymorphic DNA.

The genus Nicotiana consists of 64 recognized species of which, only two species, tabacum and rustica are cultivated extensively. Wild Nicotiana species are storehouses of genes for several diseases and pests, besides genes for several important phytochemicals and quality traits, which are not present in cultivated varieties. Randomly amplified polymorphic DNA (RAPD) analysis was used to determine the degree of genetic variation in the genus Nicotiana and to develop species specific markers. Twenty two species and two interspecific hybrids were analyzed by using 18 random decamer primers. Genetic polymorphism abounds among the wild species of genus Nicotiana (99.5 %) as evidenced by the high degree of polymorphism in RAPD profiles. The pairwise similarity measures in the species of subgenus Rustica was 0.252 whereas in the subgenus Tabacum was 0.189, suggesting that there was significant diversity among the species of these subgenera. In the species of subgenus Petunioides, the range of pairwise similarity measures was 0.128 to 0.941. The clustering pattern coincided with the traditional classification of Nicotiana species. All the primers generated specific bands in the various species. Thirty six species-specific markers identified in the present study will be useful in interspecific breeding programs.