热激处理对棉花种子萌发及幼苗生长发育的影响

Effects of Heat Shock Treatment on Cotton Seed Germination and Seedling Growth

摘要:

为了探索热激处理对棉花种子萌发及幼苗生长发育的影响，在不同时期(种子吸胀期前、吸胀期和萌动期)、不同热激温度(39℃、42℃、45℃)和不同热激时间(4 h、8 h、12 h、16 h)条件下进行试验，测定发芽率、发芽势、发芽指数、株高、根体积、地上部鲜重、地下部鲜重、地上部干重、地下部干重及SPAD值。结果表明，不同时期的热激处理对种子萌发及幼苗生长发育的影响最大，处理温度及处理时间影响较小。吸胀期前热激处理的发芽率(89.86%)显著高于吸胀期及萌动期；吸胀期前与萌动期热激处理促进地上部生长，抑制地下部生长；吸胀期热激处理表现为抑制株高生长，但促进根系发育，同时增加生物量积累。通过主成分分析对10个测定指标进行综合评价，其中，萌动期、45℃、8 h处理组合最优。

Abstract:

To investigate the effects of heat shock treatment on cotton seed germination and seedling growth and development, experiments were conducted under different treatment stages(before imbibition, during imbibition,and at the germination stage), various heat shock temperatures(39 ℃, 42 ℃, and 45 ℃), and different heat shock durations(4 h, 8 h, 12 h, and 16 h). The measured indicators included germination rate, germination potential, germination index, plant height, root volume, aboveground fresh weight, underground fresh weight, aboveground dry weight, underground dry weight, and SPAD value. The results showed that the timing of heat shock treatment had the most significant impact on seed germination and seedling growth and development, while the effects of treatment temperature and duration were relatively minor. The germination rate(89.86%) under heat shock treatment before imbibition was significantly higher than that under treatments during imbibition and at the germination stage. Heat shock treatments before imbibition and at the germination stage promoted aboveground growth but inhibited underground growth; in contrast, heat shock treatment during imbibition suppressed plant height growth while enhancing root development and increasing biomass accumulation. Principal component analysis(PCA)was employed to comprehensively evaluate the 10 measured indicators, revealing that the optimal treatment combination was heat shock applied at the germination stage, 45 ℃, and for 8 h.