摘要：

为探究大豆种子生活力测定的最适染色条件以及种子萌发期重要生理指标的变化,采用单因素和正交试验设计筛选适用于大豆种子生活力检测的氯化三苯基四氮唑(TTC)染色最佳组合;并分析大豆种子在不同萌发环境下的发芽率和种子内源细胞壁水解酶的变化。单因素分析结果表明,有无吸胀处理对于种子染色至关重要,且低浓度(0.1%)的TTC溶液会显著降低种子的染色率。多因素正交试验结果表明,大豆种子染色的最佳条件是:吸胀时间6 h,TTC浓度1%,染色温度35 ℃,染色时间60 min。该组合下的种子染色率为98.5%。萌发率试验表明,光、暗条件对于萌发进程无显著的影响;高水量下大豆萌发受到抑制,而低水量下种子却有着较高的萌发率;在一定温度范围内,低温可推迟种子萌发,但却提高了种子的最终萌发率。酶活性试验表明,种子在光、暗条件下萌发时,种胚内的纤维素酶、多聚半乳糖醛酸酶和β-半乳糖苷酶活性无显著变化,而木葡聚糖内转糖基酶在光照下的活性却显著高于其在暗环境下的活性。在不同吸胀水量下,纤维素酶和多聚半乳糖醛酸酶活性无显著变化;β-半乳糖苷酶活性随着水量的增加逐渐上升,而木葡聚糖内转糖基酶活性却呈现与之相反的趋势。值得注意的是,萌发温度的升高能够显著增加4种细胞壁水解酶在大豆胚中的活性。综上,TTC染色结果对于快速判断大豆种子生活力,完善大豆种子质量检测技术规程具有重要的实践意义;探索大豆种子在不同萌发条件下的细胞壁水解酶活性有助于揭示双子叶植物种子萌发的机制。

关键词: 大豆, 种子生活力, 种子萌发, 细胞壁水解酶, 活性氧

Abstract:

In order to investigate the optimal staining conditions for soybean seed viability determination and the changes of important physiological indexes during seed germination stage,single factor and orthogonal tests were used to design and screen the optimal combination of Triphenyltetrazolium chloride(TTC)for soybean seed viability determination.The changes of germination rate and endogenous cell wall hydrolase of soybean seeds under different germination conditions were also analyzed.Univariate analysis showed that the presence or absence of imbibition treatment was critical for seed staining,and low concentration(0.1%)TTC solution significantly reduced the seed staining rate.The results of multi-factor orthogonal test showed that the optimal dyeing conditions of soybean seeds were as follows:imbibition time 6 h,TTC concentration 1%,dyeing temperature 35 ℃,dyeing time 60 min.The dyeing rate of seeds in this combination was 98.5%.Germination rate test showed that light and dark conditions had no significant effect on germination process.Seed germination was inhibited under more water and promoted under less water.In a certain temperature range,low temperature delayed the germination process of seeds,but increased the final germination percentage of seeds.The activities of cellulase,polygalacturonase and β-galactosidase did not change significantly when seeds germinated under light and dark conditions,while the activities of xyloglucan endoglycosylase under light were significantly higher than those under dark conditions.The activities of cellulase and polygalacturonase did not change significantly when seed were imbibed in various water content.The activity of β-galactosidase increased gradually with the increase of water,while the activity of xyloglucan endoglycosylase showed an opposite trend.It is noteworthy that the activities of four cell wall hydrolases in soybean embryos were significantly elevated with the increase of germination temperature.In conclusion,TTC staining results have important practical significance for the rapid determination of soybean seed viability and the improvement of soybean seed quality testing technical regulations.Exploring the activity of cell wall hydrolase in soybean seeds under different germination conditions will help to reveal the mechanism of seed germination in dicotyledons.

Key words: Soybean, Seed viability, Seed germination, Cell wall hydrolase, Reactive oxygen species