Abstract:

To explore the suitable temperature for grafted tomato seedlings, the growth situation and change of SOD, POD activity of grafted tomato seedlings under three treatments were studied. The results showed that, both the root and shoot of seedlings were inhibited and disordered root/stem ratio were observed under 20/17℃ condition. However, the total biomass of leggy seedlings were found in 30/27℃ treatment. Appropriate root/stem ration and strong stem as well as the highest SPAD readings were showed under 25/22℃ condition. Compared to 25/22℃ treatment, the readings of SPAD were reduced by 20% and 13% in 20/17℃ and 30/27℃ treatments, respectively. The activity of SOD of grafted seedlings under 20/17℃ and 30/27℃ were 237.58 U/(g?FW) and 254.39 U/(g?FW), 114 U/(g?FW) and 97.19 U/(g?FW) lower than those in 25/22℃ treatment, correspondingly. Relatively higher activity was observed under 30/27℃ situation, but the difference was insignificant. To sum up, the optimal temperature at day and night for grafted tomato seedlings are around 25℃ and 30℃.