不同处理对喜马拉雅紫茉莉种子萌发和幼苗生长的影响

Effects of Different Treatments on Seed Germination and Seedling Growth of Mirabilis himalaica

为了提高濒危藏药植物喜马拉雅紫茉莉种子的发芽率,采用培养皿纸床发芽法,研究不同消毒方法、浸种时间和植物生长调节剂对种子萌发和幼苗生长的影响。结果表明,用无菌水冲洗5次后直接接种的种子,带菌率为3.74%,发芽率为31.67%。用75%乙醇1 min+0.1%HgCL^(-1)2 min和75%乙醇1 min+3%H;O;3 min消毒效果较好,但对种子萌发具有一定的抑制作用。质量浓度为2~10 mg·L^(-1)的IBA、2,4-D、NAA和IAA对种子的萌发主要表现为抑制作用。6-BA 2~10 mg·L^(-1)和GA;20~400 mg·L^(-1)对种子的萌发主要表现为促进作用,其中用6-BA 10 mg·L^(-1)培养的种子发芽指标最好,发芽率、发芽势、发芽指数和活力指数分别为63.67%、62.00%、16.47和1.43,其次为GA;300 mg·L^(-1),4项发芽指标分别为55.00%、53.13%、14.44和1.38。质量浓度为2~10 mg·L^(-1)的6-BA、IBA、IAA和20~400 mg·L^(-1)的GA;对幼苗生长有明显的促进作用,其中GA;250~400 mg·L^(-1)处理下,幼苗平均干重大于8.00 mg。质量浓度为2~10 mg·L^(-1)的NAA和2,4-D不利于幼苗干物质的累积。

To improve the germination rate of the endangered Tibetan medicine plant Mirabilis himalaica, the effects of different disinfection methods, seed-soaking time and plant growth regulators on seed germination and seedling growth were studied by using the germinating method of paper bed in petri dish. The results showed that the bacteria-carrying rate and germinating rate were 3.74% and 31.67% respectively for the seeds directly inoculated after washing with sterile water for 5 times. The sterilization methods of the treatment with 75% ethanol for 1 min combined with 0.1% HgCL^(-1)for 2 min or 3% H;O;for 3 min had better disinfection effect, but both treatments had certain inhibitory effect on seed germination. There were inhibiting effects of IBA, 2,4-D, NAA and IAA on seed germination while the mass concentrations of these plant hormones varied from 2-10 mg·L^(-1). The 6-BA with concentration of 2-10 mg·L^(-1)and GA;with concentration of 20-400 mg·L^(-1)could promote seed germination, among which seeds cultured with 10 mg·L^(-1)6-BA had the best germination index. Germination rate, germination potential, germination index and vigor index were 63.67%, 62.00%, 16.47 and 1.43, respectively. Followed by 300 mg·L^(-1)GA;, the corresponding indexes were 55.00%, 53.13%, 14.44 and 1.38, respectively. The 6-BA, IBA and IAA with concentrations of 2-10 mg·L^(-1)and GA;with concentrations of 20-400 mg·L^(-1)promoted the growth of seedlings, and the average dry weight of seedlings under the treatment of GA;with concentration of 250-400 mg·L^(-1)was higher than 8.00 mg. The NAA and 2,4-D with concentration of 2-10 mg·L^(-1)were not conducive to dry matter accumulation in seedlings.