Lettuce (Lactuca sativa L.) is one of the major leafy and salad vegetables. Identification and assessment of the genetic potential of lettuce germplasm is crucial in the breeding programs. Assessment of qualitative and quantitative traits of Iranian lettuce germplasm collected from different provinces was conducted in the research field of seed and plant improvement institute, Karaj in March 2010. Genotypes were sown on rows with the length and spacing 3 m and 60 cm, respectively. Morphological characteristics were evaluated based on IPGRI descriptors. Results revealed high variability amongst genotypes. Three types of lettuce were identified including stem, leaf and romaine for the first time in Iranian lettuce. There were significant positive correlations between growth period to bolting and flowering in genotypes. Qom genotype and lines 15 and 25 were sensitive to bolting, and Pich-e-Ahvaz, Siah-e-Dezful, Sefid-e-Neyshaboor, Siah-e-Neyshaboor and Varamin 3 were detected resistant. Genotypes were separated into three groups based on cluster analysis in which some groups had above average values for some traits. Genotypes with desirable characteristics can be identified to improve traits and use in breeding programs can be used later.
