Abstract

Determination of genetic diversity among Zimbabwean and exotic flue-cured tobacco varieties is important for variety identification and for rational use of germplasm in breeding programs. This research investigated genetic diversity among Zimbabwean and exotic flue-cured tobacco varieties using phenotypic traits and simple sequence repeats markers. A total of twenty eight flue-cured cultivars (sixteen from China, six from Brazil, two from South Africa and four from Zimbabwe) were studied. Phenotypic data for tobacco descriptor traits were collected from a field experiment carried out using standard cultural practices for flue-cured tobacco in Zimbabwe. A sample of fifteen cultivars was genotyped with simple sequence repeats markers. Low levels of diversity were detected among the cultivars using analysis of either phenotypic or DNA marker data. Pair wise genetic similarities ranged from 0.80 to 0.99.  Genetic distances determined were all less than 0.4. The study suggests the need for conservation of germplasm used in Zimbabwe to avoid further genetic erosion.

 Key words: Fingerprinting, genetic erosion, genetic conservation, Nicotiana tabacum.