低温胁迫下植物生长调节剂对玉米苗期光合及主要生理特性的影响

Effects of plant growth regulators on photosynthesis and major physiological properties of maize seedlings under cold stress

以"富民985"玉米杂交种为材料,通过盆栽,苗期低温胁迫下植物生长调节剂聚糠萘(PKN)、多效唑(MET)和矮壮素(CCC)对提高玉米的耐冷效果进行了研究。结果表明:低温对玉米造成的不利影响随着时间的延长而加重。在低温处理前,玉米叶片上喷施PKN、MET和CCC等后,在遇到低温冷害时,不仅使叶片Fv/F0、Fv/Fm和SPAD值的降低,而且减轻超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)等抗氧化酶活性的降低,并降低MDA的积累。尤其是经植物生长调节剂处理的玉米,在解除低温影响后,各项耐冷指标的恢复均显著快于对照(P<0.05)。说明在玉米苗期叶片上喷施PKN、MET和CCC等植物生长调节剂,有助于减轻低温冷害对玉米的不良影响,提高玉米的耐冷性;其中,MET提高玉米苗期耐冷性的总体效果显著优于PKN和CCC,而PKN的总体效果略好于CCC。

Maize seedlings of the hybrid Fumin 985 as materials,influences of plant growth regulators of PASP-KI-NAA（PKN）,paclobutrazol（MET）and chlormequat chloride（CCC）on chlorophyll fluorescence parameters,antioxidant enzyme activities and MDA content in maize leaves under cold stress were determined.The results showed that low temperatures led unfavorable effects on maize plants,but spraying PKN,MET or CCC on leaves of maize seedlings before low temperature treatment could effectively reduce the detrimental effect of low temperature on maize plants.In comparison with the control,spraying growth regulators on maize leaves before low temperature treatment could reduce the decrease of Fv/F0,Fv/Fm and SPAD values as well as the activities of superoxide dismutase（SOD）,peroxidase（POD）and catalase（CAT）,and reduced the accumulation of malondialdehyde（MDA）in maize leaves.Particularly,after removing low temperature treatment,all the parameters determined of maize seedlings treated by growth regulators were recovered obviously faster than the control.Overall,among the plant growth regulators,the effect of MET on improving the cold resistance for maize seedlings was better than PKN and CCC,whereas PKN was a little bit better than CCC.