磷酸胆碱合剂对不同种植密度玉米叶片衰老生理的影响

针对东北地区低温冷凉气候区密植条件下玉米叶片早衰现象,于大田条件下,研究了不同种植密度下磷酸胆碱合剂对京单28和先玉335叶片衰老相关指标及产量性状的影响。结果表明,随种植密度增加,玉米叶片保绿度、叶绿素含量下降;超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性降低,丙二醛(MDA)含量升高。化控处理后,不同种植密度下,2个玉米品种叶绿素含量提高了6.57%~23.40%,保绿度提高了4.5%~13.9%;SOD、POD、CAT活性在中高密度条件下较对照升高了4.76%~21.64%,MDA含量较对照降低4.39%~11.82%;穗长、行粒数、百粒重和产量均较对照有所增加,京单28产量最高增加了398.3kg/hm2,先玉335产量最高增加了774.2kg/hm2。以不同品种不同密度下的各生理指标与产量进行相关分析,结果表明除MDA含量与产量呈极显著负相关外(r=-0.810**),其余都表现出正相关,其中POD活性(r=0.660*)达到了显著水平。表明磷酸胆碱合剂可以延缓玉米叶片的衰老。

EFFECT OF ECK MIXTURE TREATMENT ON MAIZE LEAF SENESCENCE UNDER DIFFERENT PLANTING DENSITIES

Effects of plant growth regulator ethylene-CCC-PASPK(ECK) on leaf senescence physiology and yield characters were investigated under different planting densities of Jingdan 28 and Xianyu 335 in the field condition. Results indicated that leaf stay-green degree, chlorophyll content, activities of superoxide dismutase (SOD), peroxides (POD), hydrogen peroxidase (CAT) decreased and malondialdehyde (MDA) content increased with planting density increasing. Chlorophyll content was improved by 6.57%~23.40% under plant growth regulator (RGR) treatment and the stay-green degree increased by 4.5%~13.9%. The activities of SOD, POD and CAT were enhanced while MDA content was reduced under mid and high planting densities compared with control. PGR treatment also enhanced ear-length, grain number per row and 100-kernels weight as well as maize yield. And the yield in Jingdan 28 increased by 398.3kg/hm2 with 774.2kg/hm2 density of Xianyu 335. Furthermore, positive correlation was found between activities of SOD, POD(r=0.660*), CAT, chlorophyll content and yield, while negative correlation was observed in MDA content and yield(r=-0.810**). Thus, we conclude that ECK can slow maize leaf aging and oxidation.