石斛顶叶组物种的碳同化途径类型
Elucidating the types of carbon assimilation pathways in Dendrobium section Densiflora
林雅君 1吴宇苇 1韦春怡 1兰思仁 1李明河1
作者信息
- 1. 福建农林大学风景园林与艺术学院,福建 福州350002
- 折叠
摘要
石斛顶叶组(Dendrobium section Densiflora)物种具有重要的观赏和药用价值,为更科学高效地对其进行育种和栽培管理,以该组所有国产的8个原生物种:长苏石斛(D.brymerianum)、鼓槌石斛(D.chrysotoxum)、密花石斛(D.densiflorum)、苏瓣石斛(D.harveyanum)、具槽石斛(D.sulcatum)、球花石斛(D.thyrsiflorum)、小黄花石斛(D.jenkinsii)和聚石斛(D.lindleyi)为研究对象,通过进行稳定碳同位素分馏值(δ13C)、全天CO2净吸收值和早晚可滴定酸值测定,探究其光合碳同化途径类型.结果表明:聚石斛和小黄花石斛的δ13C值大于-20‰,为景天酸代谢(CAM)途径植物;其余6种均小于-20‰,为C3植物.干旱胁迫后,小黄花石斛的整个夜间净CO2吸收速率为正值,聚石斛2/3以上的夜间净CO2吸收速率为正值,聚石斛和小黄花石斛的暗期CO2净吸收量显著高于昼期,同时早晚可滴定酸差值(△H+)显著高于C3植物,进一步支持聚石斛和小黄花石斛为CAM植物;C3植物昼期CO2净吸收量均显著高于暗期,其中长苏石斛的△H+小于0,为C3植物中的专性C3物种,而其余5个物种的△H+均大于4 mmol·kg-1,为C3植物中的兼性CAM物种.
Abstract
Dendrobium section Densiflora species hold important ornamental and medicinal value. To improve the efficiency of breeding and cultivation,in this study,we aimed to elucidate the types of photosynthetic carbon assimilation pathways in D. brymerianum,D. chrysotoxum,D. densiflorum,D. harveyanum,D. sulcatum,D. thyrsiflorum,D. jenkinsii,D. lindleyi,all of which are known native Chinese species of Dendrobium section Densiflora,by analyzing stable carbon isotope ratios (δ13C),diurnal net CO2 assimilation,and titratable acidity. The results showed that the δ13C values of D. Jenkinsii and D. Lindleyi were greater than-20‰,identifying as crassulacean acid metabolism (CAM) plants,while the δ13C values of other 6 species were less than-20‰,identifying as C3 plants. Following drought stress,D. Jenkinsii had net CO2 uptake during the whole night,and D. Lindleyi had net CO2 exchange for over two-thirds of the night. The difference in titratable day and night acid level (△H+) between these two plants was markedly higher than that of C3 plants,providing further evidence that both are CAM plants. All C3 species exhibited marked net CO2 uptake during the daytime;however,acid accumulation in them was more markedly at night,exceeding 4 mmol·kg-1 . The only exception was D. Brymerianum,which did not show night acid accumulation,indicating that this effect is unique to the obligate C3 plants,while the remaining five species were facultative CAM plants.
关键词
石斛属/顶叶组/碳同化途径/干旱胁迫/景天酸代谢Key words
Dendrobium/section Densiflora/carbon assimilation pathways/drought stress/crassulacean acid metabolism引用本文复制引用
基金项目
国家自然科学基金面上项目(32271957)
出版年
2024
国家科技期刊平台
NSTL
万方数据