玉米种子人工老化过程中生理特性与种子活力的变化

种子贮藏过程中各项活力逐渐降低,即种子的老化。老化不仅影响种子萌发与幼苗的生长,也会影响到后期植株的产量与品质。以玉米自交系昌7-2、杂交组合郑单958和农大108的F1种子为试验材料,通过人工加速老化的方法,对3个品种(系)的玉米种子人工老化过程中生理特性与种子活力的变化规律进行了分析。结果表明,玉米种子的发芽势、发芽率、发芽指数和活力指数均随老化时间的延长而降低;过氧化物酶(POD)的活性随老化时间的增加而降低,与种子的各项活力指标呈正相关,其中昌7-2与各项活力指标的相关性、郑单958与活力指数的相关性达显著水平;浸出液的相对电导率和丙二醛(MDA)含量随种子的老化时间而升高,与种子的各项活力指标呈负相关,其中昌7-2和农大108的相对电导率、昌7-2的MDA含量与各项活力指标的相关性均达到极显著水平,郑单958的相对电导率与活力指数和MDA含量与各项活力指标的相关性也达到显著水平;玉米种子的发芽率和活力指数随着老化时间的增加呈现一个先缓慢后加快的下降趋势;农大108的抗老化能力较弱,昌7-2和郑单958表现出较强的抗老化能力。

PHYSIOLOYCIAL AND SEED VIGOUR CHANGES OF MAIZE SEEDS DURING ARTIFICIAL AGING COURSE

Aging is an ubiquitous phenomema of crop seeds.It caused decline of seed vigor in many aspects.Seeds of maize inbred line Chang 7-2 and hybrid varieties Zhengdan 958 and Nongda 108 were used to analyze the changes of physioloyical characteristics and seed's vigor of maize by using artificial aging.The results showed that germination potential,germination ratio,germination index and vigor index declined along with seeds aging time.Activity of POD,which was positively correlated with virous vigor indexes of maize seeds,was also declined with aging time.The correlation between the POD activity of Chang 7-2 and various vigor indexes,the correlation between the POD of Zhengdan 958 and vagor index were significant.But the relative conductance rate and malonyldialdehyed(MDA) content increased with aging time and was negatively correlated with various vigor indexes of maize seeds.Among those,the correlation between the relative conductance of Chang 7-2 and Nongda 108 with various vigor indexes was most significant.The correlation targets between conductance rate of Zhengdan 958 with vigor index,MDA content with various vigor were significant too.The decline trends of germination rate and vigor index were slow at beginning and then quicken along with aging time.The ability of aging resisance of Chang 7-2 and Zhengdan 958 were stronger than that of Nongda 108.