不同发育时期和生长条件下香椿种苗亚硝酸盐含量的动态变化

采用GB/T 5009.33 — 2003 盐酸萘乙二胺分光光度法，对香椿种子休眠期、露白期、子叶期、幼苗期等不同发育时期亚硝酸盐含量进行系统测定，同时对香椿幼苗期不同部位的亚硝酸盐含量、生长于室内和室外的香椿体内亚硝酸盐含量进行测定。结果表明：香椿种子在萌发和生长过程中，其体内的亚硝酸盐含量呈递减趋势：种子内的亚硝酸盐含量最高，幼苗的亚硝酸盐含量最低，露白期和子叶期幼苗的亚硝酸盐含量居中；不同立地条件下，生长于室内的香椿苗亚硝酸盐含量高于生长于室外的香椿苗。

Nitrite Content in Toona Tissues at Different Developmental Stages and Growth Conditions

Nitrite content in Toona tissues of dormant seeds, sprouting seeds, young seedlings at cotyledon stage, and fully grown seedlings was determined by nitrite-N-(1-naphthyl)ethylene diamine dihydrochloride spectrophotometric method. Meanwhile, nitrite content in different parts of seedlings grown indoors and outdoors was also determined at different developmental stages. Endogenous nitrite content exhibited a decrease trend during sprouting stage and growth stage of seedlings. Nitrite level was the highest in Toona seeds, and the lowest in Toona seedlings. At cotyledon stage, nitrite content in root was higher than in shoot, whereas at late seedling stage, nitrite content in shoot was higher than in root. Nitrite content in the buds and newly formed shoots of Toona grown indoors was higher than those grown outdoors.