人工老化处理时间对黄瓜种子生理特性及解剖结构的影响OA

To investigate the effects of aging on the viability,physiological changes,and anatomical structure of cucumber seeds,seeds of the new cucumber variety Deli No.1 was used as the experimental materials.An artificial accelerated ag-ing method with high temperature and high humidity(45℃,95%RH)was adopted to determine the seed germination in-dices and physiological and biochemical indices after different aging durations.Meanwhile,paraffin sectioning was em-ployed to observe the anatomical structure changes of the seeds.The results indicated that with the extension of aging time,the germination rate of seeds decreased continuously:Compared with the control(0 d of aging),the germination rate after 6 and 9 days of aging dropped significantly by 24.45 and 84.45 percentage points,respectively.The electrical conductivity and malondialdehyde(MDA)content exhibited significant increasing trends,the content of soluble protein and soluble sugar decreased markedly;the activity of catalase(CAT)and superoxide dismutase(SOD)decreased signifi-cantly.The levels of H2O2 and O2-·peaked on day 9 of aging and subsequently declined in tandem with the loss of seed via-bility,but remained higher than those of the control.The results of 24 h imbibition after aging indicated that imbibition was beneficial to the activation of repair enzymes in high-vigor seeds(with a germination rate of over 94.43%);whereas for low-vigor seeds(with a germination rate of below 36.67%),imbibition treatment aggravated oxidative stress.With the deepening of aging degree,the anatomical structure of seeds changed:The inclusions in embryo and cotyledon cells were degraded,and the structure was severely damaged.The results of this study can provide a theoretical basis for the re-search on the physiological mechanism of cucumber seed aging,and a scientific reference for the preservation and utiliza-tion of cucumber germplasm resources.