Welcome to Chinese Journal of Ecology! Today is Share:

cje

Previous Articles     Next Articles

Stomatal and non-stomatal limitations on photosynthesis of flag leaf of medium mature indica rice at early earring stage under natural conditions.

YE Zi-piao1, ZHENG Zhou2, KANG Hua-jing3, WANG Fu-biao1, AN Ting1, DUAN Shi-hua2*   

  1. (1College of Math and Physics, Jinggangshan University, Ji’an 343009, Jiangxi, China; 2School of Life Sciences, Jinggangshan University, Ji’an 343009, Jiangxi, China; 3Wenzhou Academy of Agricultural Sciences, Wenzhou 325006, Zhejiang, China).
  • Online:2019-04-10 Published:2019-04-10

Abstract: This study aims to explore the characteristics of stomatal and non-stomatal limitations on photosynthesis of flag leaves of medium mature indica rice (Oryza sativa) under natural conditions in Jiangxi. Leaf gas exchange of four rice cultivars (i.e.restorer line R7-35, sterile line Jingda 3S, F1 hybrid of Jingda 3S/R7-35, and CK 9311) at the early earring stage were examined using a LI-6400 portable photosynthesis analyzer. The light-response curves of net assimilation rate (An), stomatal conductance (gs), intercellular CO2 concentration (Ci) and stomatal limitation value (Ls) were measured. The results showed that the saturated light intensity (Isat) values, corresponding to the maximum An, for the four cultivars were 1500, 1800, 1200, and 1200 μmol·m-2·s-1, respectively. The gs of R7-35, Jingda 3S and 9311 increased with the increases of light intensity (I). At higher I levels, non-stomatal limitation played a major role in limiting An of the four cultivars. The I values corresponding to the minimum Ci were 1600, 1600, 1400, and 1600 μmol·m-2·s-1, respectively. The saturation I values corresponding to the maximum Ls were 1400, 1200, 1400, and 600 μmol·m-2·s-1, respectively. If the decrease ofCi and the increase of Ls were the main reasons for the decreases of photosynthetic rate, the criterion of stomatal factor would be biased. Cultivar 9311 showed a decrease ofCi with the increases ofI until reaching 1600 μmol·m-2·s-1, an increase of Ls with the increases of I until reaching 600 μmol·m-2·s-1, and a nonlinear increase ofAn with the increases of I until reaching 1200 μmol·m-2·s-1. These results indicated that a combination of Ci decrease and ofLs increase would not necessarily lead to a decrease in An. Accordingly, we propose a new criterion for determining non-stomatal limitation whether it had Isat and for determining stomatal limitation whether it had the maximum gs.

Key words: Haitan Island, land use, ecological risk, exploratory spatial data analysis (ESDA).