The International Union for the Protection of New Varieties of Plants (UPOV) promotes an effective system of plant variety protection and encourages the development of new varieties of plants. This international convention was initiated to standardize the system efforts and strengthen policy. The establishment of cultivar discrimination system is very important to distinguish varieties between domestic and foreign agricultural products. It is necessary for the protection of breeders’rights. In addition, it will help for more efficient and quality management of plant breeding. This study was conducted to identify and group rice varieties based on agro-morphological characteristics such as plant height, panicle length, number of tillers, culm length, leaf length, leaf width, leaf pigments and flag leaf angles. Using these parameters, statistical analysis classified a total of 243 rice varieties bred in Korea into four groups. Most rice varieties did not exhibit anthocyanin pigments on the leaves particularly on the first leaf, leaf blade, leaf sheath and auricle, except for varieties classified as black rice. Results of phylogenetic and principal component analysis (PCA) indicated that these varieties formed three largely distinct clusters according to their ecotype and morphological differentiation. This result would be useful in rice varietal identification for the protection of breeders’variety rights.

Salt stress is one of major restrictions for the production of lettuce. In order to identify promising lettuce genotypes having tolerance against salt stress, effect of different sodium chloride (NaCl) concentrations (0, 100, and 200 mM) on electrolyte leakage and growth of thirty-two lettuce landraces from Korea was evaluated. Screening salt tolerant genotypes based on cluster analysis using data of electrolyte leakage discriminated 'IT105183' and 'IT195057' as the most salt tolerant landraces. More importantly, salinity significantly reduced growth of lettuce, but the reduction rates of growth caused by salt stress in salt-tolerant genotypes were much smaller than those in salt-sensitive genotypes. These results indicate that 'IT105183' and 'IT195057' have high potential for being used as parents to improve salt tolerance in other lettuce cultivars.