温度对嫁接番茄幼苗生长及SOD、POD活性的影响

Effect of Temperature on Growth and SOD,POD Activity of Grafted Tomato Seedlings

为探明华南地区番茄嫁接苗的适宜生长温度,试验研究了3个温度处理下番茄嫁接苗的生长状况及其叶片内保护酶(SOD、POD)活性的变化。试验结果表明:20/17℃处理下的地上部和根系生长都受到抑制,根冠比失调;30/27℃时植株出现徒长迹象,且整株生物量下降;25/22℃环境条件下,嫁接苗根冠协调,茎秆健壮,光合能力较强。相比于25/22℃环境,20/17℃的相对低温处理和30/27℃的相对高温处理导致番茄嫁接苗的SPAD读数分别下降20%和13%,叶片的SOD酶活性为237.58U/(g.FW)和254.39U/(g.FW),分别比25/22℃处理下的SOD活性低114U/(g.FW)和97.19U/(g.FW)。30/27℃处理下的POD活性高于另外2个处理,但差异不显著。综上所述,嫁接后的白天温度应控制在25℃左右,夜间温度为22℃左右。

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 biomasses 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 were around 25℃ and 30℃.