Location: Sugarcane ResearchTitle: Photosynthetic and canopy characteristics of different varieties at the early elongation stage and their relationships with the cane yield in sugarcane Author
Submitted to: The Scientific World
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/5/2014
Publication Date: 6/22/2014
Publication URL: http://handle.nal.usda.gov/10113/59005
Citation: Luo, J., Pan, Y.-B., Xu, L., Zhang, Y., Zhang, H., Chen, R., Que, Y. 2014. Photosynthetic and canopy characteristics of different varieties at the early elongation stage and their relationships with the cane yield in sugarcane. The Scientific World Journal. 2014:1-9. Article ID 707095. DOI: 10.1155/2014/707095. Interpretive Summary: Sugarcane is a C-4 plant that is able to produce high amounts of sugar/sucrose by assimilation carbons through a process called photosynthesis. Potential production of sugar per unit of land is determined by total cane yield multiplied by sucrose content (%) of the variety. Therefore, when and how to identify and select varieties’ superior photosynthetic capacity are two challenging topics for the sugarcane breeders. This field experiment was designed to investigate the effects of photosynthetic and canopy parameters of sugarcane plants at the Early Elongation stage on cane yield. To facilitate statistical analysis, a randomized block design was adopted with three replications. During the early elongation growth stage, three photosynthetic (PN, E, and GS) and five canopy parameters (LAI, MFIA, TD, TR, and LD) were measured using digital scientific instruments conducted. Cane yield-related traits, including plant height (PH), stalk diameter (D), single stalk weight (SSW) and the number of millable stalks per hectare (NSH) were also collected before harvesting. Using a software program called DPS, four statistical analyses, namely, VAIANCE, CLUSTER, FACTOR, and REGRESSION, were conducted on all the data collected. A regression model for cane yield was established as Cane yield = 27.19 - 1.69 × PN + 0.17 × E + 90.43 × LAI - 408.81 × LD + 0.0015 × NSH + 101.38 × D (R2=0.928**). The model provides a theoretical formula and technical guidance for the sugarcane breeders to identify new sugarcane cultivars with superior photosynthetic rate and ideal canopy structure.
Technical Abstract: During sugarcane growth, the early elongation stage is critical to cane yield formation. In order to investigate the effects of photosynthetic and canopy characteristics on cane yield, parameters of 17 sugarcane varieties were determined at the early elongation stage using CI-301 photosynthesis measuring system and CI-100 digital plant canopy imager. The data analysis showed that there were highly significant differences in leaf area index (LAI), mean foliage inclination angle (MFIA), transmission coefficient for diffused light penetration (TD), transmission coefficient for solar beam radiation penetration (TR), leaf distribution (LD), net photosynthetic rate (PN), transpiration rate (E) and stomatal conductance (GS) among sugarcane varieties at the early elongation stage. Based on the photosynthetic or canopy parameters, the 17 sugarcane varieties were classified into four categories. Through the factor analysis, nine parameters were represented by three principal factors, of which the cumulative rate of variance contributions reached 84.73%. A regression for sugarcane yield, with relative error of yield fitting less than 0.05, was successfully established as follow: sugarcane yield = 27.19 - 1.69 × PN + 0.17 × E + 90.43 × LAI - 408.81 × LD + 0.0015 × NSH + 101.38 × D (R2=0.928**). This study helps provide a theoretical basis and technical guidance for the screening of new sugarcane varieties with high net photosynthetic rate and ideal canopy structure.