In order to evaluate the effect of rootstocks on fruit flavonoid content (hesperidin and naringin) of mandarin, an experiment was conducted in a completely randomized block design with 3 replications. Eight rootstocks including sour Orange, Yuzu, Bakraee, Shangsha, Citromelo, Cleopatra, Troyer citrange and Poncirus were used for page mandarin. Also the variation of hesperidin and naringin amounts of five different mandarins including Unshiu, Clementine, Bam, Minneola tangelo and Dancy grafted on the Citrange rootstock were studied. Results showed that the highest amount of naringin was observed in fruit pulp grafted on Poncirus. On the contrary, no significant difference in the content of hesperidin was observed among different rootstocks. No meaningful difference in the content of naringin was observed in both pulp and skin of fruit under the effect of different rootstocks. It has been cleared that, the highest amount of hesperididin of pulp and skin was observed in Bam and Unshiu varietie 15/2 and 1/8 mg/100g FW srespectively. Based on the obtained results, it can be concluded that rootstock not only influences the morphological characteristics of plant, but also the nutritional and pharmaceutical properties of mandarin affect by rootstock. Based on the findings it seems that among studied cultivars Unshiu mandarin and among the rootstocks Poncirus able to produce the best pharmaceutically qualitative fruits.

Most of the plants in the citrus family are sensitive to cold stress. Therefore, the inevitable occurrence of periodic frost causes extensive damage to their functions. With the purpose of comparing 110 citrus genotypes’ reaction to the two levels of cold stress (-3°C and -6°C), 76 unknown natural genotypes and 34 known genotypes from Ramsar citrus and sub-tropical fruits research institute were studied based on the split-plot design with three replications. The results of variance analysis for the eight traits related to cold tolerance showed that there was a significant difference between the examined accessions. According to cluster analysis, the genotypes in each temperature demonstrated a relatively different grouping pattern after the employment of Euclidean distance squares and the furthest neighbors’ method. The highest amount of electrolyte leakage (55.84%), leaf water soaking (2.70) and lipid peroxidation (2.12 μg/g leaf fresh weight) were estimated at -6°C and recorded at -3°C for other traits. The relationship between the studied panels was determined by considering the common group and the traits in question. G32 and G71 genotypes were merely found to be close to the tolerant genotypes. Regarding the negative deviation from the standardized mean for electrolyte leakage (-1.367), leaf water soaking (-1.423) and lipid peroxidation (-0.684), along with the positive values of other traits (proline content, antioxidant capacity, total soluble carbohydrates and antioxidant enzymes), genotypes Poncirus, Citrumelo, off type sour orange, Sour orange, Satsuma mandarin, and Okitsu are of great usage value in cold tolerance breeding programs.