以大豆为实验材料,研究了波长为532 nm的Nd:YAG倍频激光不同功率密度和不同照射时间对大豆发芽率、幼苗平均株高、幼苗子叶及叶片异黄酮含量的影响。从光合效率和植物异黄酮合成代谢起始酶苯丙氨酸转氨酶(PAL)活性两方面探讨激光预处理大豆种子提高其幼苗异黄酮含量的机理。结果表明,大豆种子经激光预处理后,其幼苗可溶性糖、蔗糖、淀粉等光合同化产物及异黄酮合成代谢起始酶PAL活性均得到提高,其中以15 mW/mm2激光预处理大豆种子5 min的效果最佳。幼苗光合效率得到了提高,为异黄酮的大量积累提供了基础。

The pullulation ratio of the soybean,the content of the isoflavone for the cotyledon and laminae,and the mean height of the soybean seedling affected by a frequency doubled Nd:YAG 532 nm laser for different power density and time are presented in this paper. The mechanism is discussed from the activity of a phenylalanine ammonia-lyase (PAL) as an initial enzyme for synthesizing the isoflavone and the efficiency of the photosynthesis. The results show that the activity of the PAL and the products of the photosynthesis such as the soluble sugar,the sucrose,and the amylum are all increased after the soybean seed being irradiated by laser,in which the best result is occurred at 15 mW/mm2 of laser for 5 mins. At the same time,the efficiency of the photosynthesis of the soybean seedling is increased,which promotes the enormous accumulation of the isoflavone.