Investigation of Drought Stress Tolerance and Adaptation in Iranian Endemic Anise (Pimpinella anisum L.) Genotypes

Anise is an annual plant belonging to Apiaceae family and fruit essential oil of this herb is used in various pharmaceutical, cosmetic and beverage industries. Drought stress is one of the most critical limiting factors for anise production in worldwide. In this research, to finding interrelationships among different traits and performance, some anise genotypes were evaluated using the biplot method. In this study, 18 anise genotypes were evaluated in normal irrigation regime and drought stress conditions according to a randomized complete block design with three replications at the field of the Western Australia University (UWA), Australia. Fifteen phonological, morphological and physiological traits were measured. Results indicated the positive and significant correlations between yield and fruit number and fruit thousand weight in both conditions. Due to the negative correlation between phonological features with fruit yield in two different irrigation conditions, it could be concluded that to have genotypes with high fruit yield, selection for early ripening genotypes should be done in anise. In this study, a significant correlation was observed between fruit yield and relative water content in the stress condition. Therefore, this trait can be used as a physiological index to evaluate drought tolerance in anise. According to cluster analysis based on the measured traits, genotypes were divided into 3 groups in both non-stress and stress conditions. According to the results of the comparison of the means of the groups in non-stress and drought stress conditions, genotypes No. 1, 5, 6, 11, 12, 14, 15 and 16 were identified as the most drought-tolerant genotypes. These genotypes could be utilized in breeding programs for further improvement of drought tolerance in anise germplasm.