摘要： 研究黄顶菊生长特性及光合特性,为黄顶菊的有效防治提供理论依据。在非耕地上人工播种黄顶菊,对其出苗率、株高增长、叶片增长及单位面积黄顶菊鲜质量变化等指标进行了测定,同时对黄顶菊出苗率与土壤温湿度关系进行了调查。采用丙酮直接浸提法测定了黄顶菊苗期、生长期、开花初期叶片叶绿素含量。利用LI-6400光合作用测定系统,测定了黄顶菊叶片不同生长时期的净光合速率、净光合速率日变化,同时测定了黄顶菊光合-光响应曲线。结果表明,黄顶菊出苗高峰期发生在播种后8周,出苗率为74.67%,黄顶菊开始出苗温度为土壤日平均温度≥10℃,最佳出苗温度为土壤日平均温度达25℃,土壤湿度为25%～30%对黄顶菊出苗影响不大;黄顶菊株高和叶片数播种后前8周变化不大,播种后8～22周增长迅速,黄顶菊最终株高和叶龄分别为280cm和44叶;黄顶菊单位面积鲜质量变化为播种后8～22周鲜质量增长幅度较大,平均增加2275g/周,到播种后22周黄顶菊鲜质量达到最大值26781g/m²。黄顶菊苗期、生长期及开花初期叶片叶绿素含量分别为0.392%,0.409%及0.508%。黄顶菊苗期、生长期及开花初期叶片最大净光合速率分别为23.6,37.5和41.5μmol/(m²·s)。黄顶菊在苗期、生长期、开花初期的净光合速率日变化均呈现单峰式曲线变化,无光合"午休"现象,最大净光合速率出现在11:00,且三者的变化趋势不同。黄顶菊的光饱和点为1512μmol/(m²·s),光补偿点53.7μmol/(m²·s)。

关键词: 黄顶菊, 生长特性, 光合作用, 生物入侵

Abstract: Growth and photosynthetic characteristics of Flaveria bidentis were studied. The results provided scientific basis for effective controlling Flaveria bidentis. Flaveria bidentis were sown by hand in no tillage. The Flaveria bidentis indexs of seedling emergence rate,plant height growth,leaves growth and fresh weight changes per square unit were measured. Relationships between Flaveria bidentis seedling emergence rate and soil temperature and moisture were surveyed. Flaveria bidentis leaves chlorophyll content were measured using acetone direct lixiviating method at seedling stage,vegetation period and early flowering stage. Net photosynthetic rate and diurnal changes of net photosynthetic rate at different growth stage of Flaveria bidentis leaves,and photosynthesis-light response curve were measured using LI-6400 portable photosynthesis system. The results showed that,Flaveria bidentis seedling emergence peak occurred after sown 8 weeks,and the seedling emergence rate was 74. 67%. Average soil temperature was more than 10℃ Flaveria bidentis beginning emergence,and the optimal soil average temperature for Flaveria bidentis emergence was 25℃. It had little effect on Flaveria bidentis emergence when the soil temperature and moisture was at 25% to 30%. The plant height and leaf number of Flaveria bidentis had little change before sown 8 weeks,but from sown 8 to 22 weeks grown rapidly. The final plant height and leaf number was 280 cm and 44 leaves.The fresh weight of Flaveria bidentis per square unit increased rapidly from sown 8 to 22 weeks,and the average increment one week was 2 275 g. The fresh weight maxium value was 26 781 g /m2 after sown 22 weeks. Flaveria bidentis leaves chlorophyll content were 0. 392%,0. 409% and 0. 508% respectively at seedling stage,vegetation period and early flowering stage. Flaveria bidentis leaf most net photosynthetic rate were 23. 6,37. 5 and 41. 5 μmol /(m²·s) respectively at seedling stage,vegetation period and early flowering stage. Diurnal changes of net photosynthetic rate were one-peak curve at the three growth stage of Flaveria bidentis leaves. There was no photosynthesis midday depression phenomenon. The peak of net photosynthetic rate was measured at 11: 00 a. m.. The curve of durnal changes of net photosynthetic rate were different from each other which measured at the three growth stage of Flaveria bidentis. Light saturation point of photosynthesis was 1 512 μmol /(m²·s). Light compensation point of photosyntesis of Flaveria bidentis leaves was 53. 7 μmol /(m²·s).

Key words: Flaveria bidentis, Growth characteristic, Photosynthetic characteristic

中图分类号: 

• Q948