向日葵光合作用能力最强叶片探讨及其光合作用日变化研究

Exploration and Research on the Strongest Photosynthetic Capacity and Diurnal Photosynthetic Dynamics Leaf of Sunflower

以"先瑞9号"、"T9938"2个向日葵品种为试材,在其初花期利用Li-6400光合仪,依次从植株顶部到基部测定不同节位叶片的光合作用及光合能力最强叶片的光合作用日变化,以规范测定标准并为比较、分析向日葵叶片光合能力提供指导。结果表明:对不同节位向日葵叶片,光合速率、气孔导度"先瑞9号"以第5节位最高,"T9938"以第6节位最高;蒸腾速率"先瑞9号"以第6节位最高,"T9938"以第7节位最高;胞间CO2浓度"先瑞9号"以第5、6节位最低,"T9938"以第6节位最低;2个品种光合作用能力最强节位叶片分别是"先瑞9号"为第5节位叶片,"T9938"为第6节位叶片,其光合速率、气孔导度均在11:00时达到最高值,胞间CO2浓度在11:00时达到最低值;蒸腾速率"先瑞9号"在13:00时达到最高值,"T9938"在14:00时达到最高值;选择顶部完全发育、完全伸展的最高节位叶片,在11:00时测定,其测定值可代表初花期向日葵叶片的最大光合能力。

Taking two sunflower varieties of ＇Xianrui 9＇, ＇T9938＇ in early flowering stage as materials, using the Li-6400 portable photosynthesis system, from the top to the base of the plant, different nodes leaves photosynthesis been determined successively,and photosynthesis diurnal change of the strongest photosynthetic capacity leaf been determined soon after. The results showed that the highest photosynthetic rate and the highest stomatal conductance in different nodes leaves of ＇Xianrui 9＇ were the 5th node, ＇T9938＇ were the 6th node. The highest transpiration rate in different nodes leaves of ＇Xianrui 9＇ was the 6th node, ＇T9938＇ was the 7th node. The lowest intercellular CO2 concentration in differem nodes leaves of ＇Xianrui 9＇ was the 5th and 6th node, ＇T9938＇ was the 6th node. The highest photosynthetic rate,stomatal conductance of the strongest photosynthetic capacity leaf （the strongest photosynthetic capacity leaf of ＇Xianrui 9＇ was the 5th node, ＇T9938＇ was the 6th node） of two varieties were at 11：00, the lowest intercellular COx concentration were at 11 ： 00, the highest transpiration rate of ＇ Xianrui 9 ＇ was at 13 ： 00, and ＇ T9938＇ was at 14 ： 00. Selecting the top fully developed, fully extended leaf in the highest node, determining at 11 ： 00, the determination data could represent the biggest photosynthetic capacity of sunflower leaf in early flowering stage.