Novel Findings on Leaf Photosynthetic Rate under Low Light as a Major Determinant of Biomass Production

With the stagnancy of crop yield improvements, identifying new options to promote crop yields has become a major challenge for plant biologists and breeders. A large number of experimental and theoretical studies show that improving canopy photosynthesis is one of the few remaining options to dramatically increase crop yields.

Leaf area index, canopy architecture and leaf photosynthetic properties jointly determine canopy photosynthetic rate. Traditional breeding in the past few decades has improved canopy photosynthesis mainly through manipulating canopy architecture, such as selecting semi-dwarf erect lines with higher leaf area index; however, mainly due to the lack of effective parameters to select during the breeding programs, little has been done to the improvement of leaf photosynthetic properties.

Recently, professor ZHU Xinguang and his colleagues at the Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, developed a natural diversity panel including 215 rice cultivars. In their study, global linear regression model and stepwise feature selection approach were applied to uncover the genetic relatedness of key photosynthetic traits attributing to biomass accumulation. Additionally, 2.3M filtered SNPs from the 215 rice cultivars were employed to determine genomic heritability regarding key photosynthetic traits.

The results demonstrate that photosynthetic rate under low light (Alow) is highly inheritable, having a high correlation with biomass accumulation. Importantly, within 11 modern commercial cultivars, Alow shows great natural variation suggesting Alow has not been effectively used in the traditional breeding and hence is an important new parameter that can be exploited in the future rice high-yield breeding programs. 

This study entitled, "leaf photosynthetic parameters related to biomass accumulation in a global diversity survey" was published online on 25th July, 2017. It is funded by the Strategic leading project of the Chinese Academy of Sciences, Ministry of Science and Technology of China, the National Science Foundation of China, Bill and Melinda Gates Foundation and Shanghai Natural Science Foundation.

Article website:
http://www.plantphysiol.org/content/early/2017/07/27/pp.17.00332
 

Caption:
(A). The Pearson correlation between leaf photosynthetic parameters and biomass accumulation under different locations;
(B). Identification of critical photosynthetic parameters controlling biomass accumulation using stepwise feature selection method.
(C-D). The distribution of photosynthetic rates under low light (Alow) in 204 rice diversity panel and 11 modern commercial lines.


Author contact:
ZHU Xinguang, Professor and principal investigator
Institute of Plant Physiology and Ecology (SIPPE)
Chinese Academy of Sciences (CAS)
300 Fenglin Road, Shanghai 200032, China
Phone: (86) 21-54924163
Email: zhuxinguang@picb.ac.cn