磷酸胆碱合剂对不同种植密度玉米叶片衰老生理的影响

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

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。

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 earlength, 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.