赤霉素和吲哚乙酸对轮叶黑藻冬芽萌发和幼苗生长的作用

为缩短轮叶黑藻冬芽的萌发时间,提高富营养化水体中轮叶黑藻冬芽的成苗率,研究了0、50、100、150、200 mg/L的赤霉素(GA)和吲哚乙酸(IAA)处理12h和24h后,轮叶黑藻冬芽的萌发状况与幼苗的生长状况.结果表明,适当浓度的GA和IAA能显著促进冬芽的萌发、提高幼苗的株高和干重、增加幼苗根的数目,但各处理对幼苗分枝数的影响不明显;冬芽的萌发对GA和IAA呈现较明显的浓度敏感性和处理时间敏感性:100、150 mg/L的IAA处理12h、50 mg/L的IAA处理24 h、150 mg/L的GA处理12h和50 mg/L的GA处理24 h,均能明显促进冬芽的萌发,而200 mg/L的IAA和GA处理24h对冬芽的萌发有明显的抑制作用;50、100 mg/L的IAA对幼苗株高的促进作用显著地大于GA,100、150 mg/L的IAA对幼苗干重的促进作用显著地大于GA,而150 mg/L的GA处理12 h和100mg/L的GA处理24h比IAA更有利于幼苗的生根.综合各指标,150 mg/L的IAA或GA处理12 h效果较好.

Effects of GA and IAA on winter buds sprouting and seedling growth of Hydrilla verticillata

In order to shorten sprouting time of Hydrilla verticillata winter buds and increase the rate of forming plantlets in eutrophic water bodies, experiments were carried out to examine the sprouting rates of H. verticillata winter buds and growth of the seedlings after the winter buds were treated with GA and IAA. The concentrations were 0, 50, 100,150 and 200 mg/L and the soaking time were 12 h and 24 h. Results showed that proper combinations of concentration and soaking time of GA and IAA could significantly accelerate the sprouting of winter buds, increase the height, dry weight and root number of seedlings. However, all the treatments had no significant effects on shoot number. Sprouting of winter buds was apparently accelerated after soaked in IAA concentrations of 100 mg/L and 150 mg/L for 12 h and 50 mg/L for 24 h,as well as in GA concentrations of 150 mg/L for 12 h and 50 mg/L for 24 h (P<0.05), but was significantly inhibited after soaked in IAA or GA concentration of 200 mg/L for 24 h (P<0.05). This indicated that sprouting of winter buds was susceptive to the concentration and soaking time of GA and IAA. IAA concentrations of 50 mg/L and 100 mg/L had stronger promoting effects on height of seedlings than GA (P<0.05), and IAA concentrations of 100 mg/L and 150 mg/L were more beneficial to dry matter accumulation (P<0.05), while rhizogenesis of the seedlings may be more promoted in GA concentrations of 150 mg/L for 12 h and 100 mg/L for 24 h than IAA (P<0.05). The results indicated that, soaking winter buds in IAA and GA concentration of 150 mg/L for 12 h would produce satisfying effects in application.