氮素营养对白及生长与多糖积累的影响

Effects of nitrogen on the growth and polysaccharides accumulation of Bletilla striata

为研究氮素营养对白及生长和多糖积累的影响,以1年龄的白及实生苗为材料进行温室盆栽培养,设置氮素形态处理组(硝态氮、铵态氮、铵硝混合)和氮素水平处理组(高中低浓度的铵硝混合处理),测定白及生长及品质相关指标。结果表明:氮素形态方面,铵硝混合处理利于白及的生长发育和干物质的积累,利于白及在弱光条件下生长,加快电子的传递且对白及块茎总多糖的积累有明显的促进作用;氮素水平方面,随着混合氮素水平增高,电子传递速率、酶活性、块茎总多糖等指标表现出先升高后降低的趋势,在15 mmol·L^(-1)时达到峰值。本研究首次对白及氮素营养的偏好进行试验,发现15 mmol·L^(-1)铵硝混合氮素有利于白及的生长和块茎总多糖的积累。

To investigate the effects of nitrogen on the growth and polysaccharides accumulation of Bletilla striata,we employed a combination of nitrogen form experiment(nitrate nitrogen,ammonium nitrogen,ammonium-nitrate mixed nitrogen)and nitrogen level experiment(ammonium-nitrate mixed nitrogen at low,middle,high concentration).One-year-old B.striata seedlings were cultured in pots as the research object,and the growth and quality related indexes were measured.Results showed that mixed nitrogen of ammonium and nitrate was beneficial to B.striata in many aspects,such as the growth,the dry weight,the adaptability to low light,the electron transport rate(ETR),and the accumulation of total polysaccharides in tubers.With the increase of nitrogen level,ETR,enzyme activities and the total polysaccharides increased first and then decreased,reaching the peak at 15 mmol·L^(-1).The preference of B.striata to nitrogen was tested for the first time.It indicates that ammonium-nitrate mixed nitrogen at the concentration of 15 mmol·L^(-1) is conducive to the growth and the accumulation of total polysaccharides in tubers of B.striata.