catalase, chlorophyll stability index, citrus, genotype, waterlogging stress.

in this research, catalase activity and leaf chlorophyll stability of satsuma mandarin on some citrus rootstocks under waterlogging condition were studied. experiment was conducted as factorial with randomized complete blocks and 6 replications. the first factor, include 7 soils from east mazandaran and the second factor included 7 different citrus rootstocks: 1. sour orange, 2. swingle citromelo, 3. carizo citrange, 4. troyer citrange, 5. c35, 6. smooth flat seville and 7. gou tou. seedlings were kept under continuous waterlogging stress condition in the second year of growth. the results showed that catalase activity and stability index of chlorophyll were significantly affected by waterlogging stress. catalase activity increased under waterlogging stress and its amount in c35 was more than other rootstocks. interaction of soil and rootstock also had significant effect on catalase activity. also, rootstocks and different soils had significant differences in changes trend of the stability index of chlorophyll. average of chlorophyll stability index in total waterlogging period showed that gou tou, c35 and swingle citromello had the highest chlorophyll stability; sour orange had the least amount. chlorophyll stability index of scion on different rootstocks in different soils indicated the different tolerance of rootstocks in various soils to waterlogging stress.