微波对老化甜菜种子萌发和早期碳氮代谢的影响

Effects of Microwave Pretreatment on Germination of Aging Beet Seed and Carbon and Nitrogen Metabolism in Early Stage Seedlings

采用2450MHz频率,以不同时间和功率的微波对老化甜菜种子进行预处理,比较了不同处理剂量对其种子萌发及早期碳、氮代谢的影响。结果表明,微波能不同程度地影响老化甜菜种子的发芽状况及早期代谢中的物质转化,其影响强度因微波处理时间不同而异,呈现出明显的剂量效应和微波调控植物代谢的双重作用。低剂量(90W、20s)处理对芽长、芽活力指数、蛋白水解酶活力及游离氨基酸总量起促进作用(P<0.05);中等剂量(270W、10s)处理,种子发芽率、芽长、芽活力指数、可溶糖、可溶蛋白含量及淀粉酶活性在处理与对照之间及各处理之间差异显著(P<0.01);高功率(450W)则随微波辐射时间的延长,种子活力及萌芽内物质转化能力均呈下降趋势。说明适宜剂量的微波辐射,提高了老化甜菜种子的生理生化代谢机能。综合评价270W 10s不仅加速了原有储存物质的水解,而且促进早期的合成代谢,为形态建成奠定了基础,为促进老化种子萌发和早期发育的最佳处理。

In present study, seeds of aging beet were exposed to microwave irradiation （240 MHz frequency） in different time length and power. Seed germination and early stage carbon and nitrogen metabolism parameters were recorded and compared for seeds treated with different doses. The results showed that microwave pretreatment affected aging beet seeds germination and resources conversion in early stage metabolism to various degrees according to different time length of microwave radiation. Dual functions of dosage effect and regulation and control of plant metabolism by microwave have been revealed. Seedling length, vigor index, proteolytic enzyme activity and total free amino acid increased under low dosage treatment （90 W, 20 s）（ P〈0.05）; Rate of seed germination, Seedling length, vigor index, soluble sugar, soluble protein concentration and activity of amylase showed significant difference not only between treatment and control, but also between each treatment （P〈0.01） under moderate doses （270 W, 10 s）; Pretreatment with 450W power decreased both seed vigor and resources conversion capabilities following the extension of microwave radiation time. The results demonstrated that physiological and biochemical metabolism of aging beet seed have been improved after treatment with appropriate dose of microwave radiation. Pretreatment dose of 270 W 10s not only accelerated the hydrolysis of the reservoir matter, but also promoted early synthetic metabolism, laid the foundation for the morphogenesis, and therefore is the best treatment to promote aging seed germination and early seedling development.