Location: Sugarcane Field StationTitle: Sugarcane plant growth and physiological responses to soil salinity during tillering and stalk elongation
|ZHU, KAI - Guangxi University|
|GAO, XINXIN - Yunan Academy Of Agricultural Sciences|
Submitted to: Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/7/2020
Publication Date: 12/8/2020
Citation: Zhao, D., Zhu, K., Momotaz, A., Gao, X. 2020. Sugarcane plant growth and physiological responses to soil salinity during tillering and stalk elongation. Agriculture. https://doi.org/10.3390/agriculture10120608.
Interpretive Summary: A pot study was conducted to investigate sugarcane plant growth and physiological responses to soil salinity. Two sugarcane cultivars (CP 96-1252 and CP 00-1101) and an Erianthus were exposed to five soil salt concentrations with 0, 38, 75, 150, and 300 mM of NaCl added. Results showed that effects of salinity on plant growth, carbon fixation, and photo-assimilate translocation depended on soil salt concentration. Plant height was the most sensitive while the number of nodes was the most tolerant to salinity among the three growth parameters. Leaf photosynthetic rate declined 13-35% when plants were exposed to the 75-300 mM salt treatments. The low leaf photosynthesis due to salinity was associated with decreases in not only stomatal conductance but also the non-stomatal factors. High soil salt concentration depressed photo-assimilate translocation from leaves to other tissues. These findings can improve our knowledge in better understanding of physiological mechanisms of salinity influence on sugarcane growth and yields.
Technical Abstract: A pot study was conducted to investigate influences of salinity on sugarcane (Saccharum spp.) plant growth, leaf photosynthesis, and other physiological traits during tillering and stalk elongation. Treatments included two commercial sugarcane cultivars (Canal Point (CP) 96-1252 and CP 00-1101) and an Erianthus with five different soil salt concentrations (0 [Control], 38, 75, 150, and 300 mM of NaCl added). Growth (tillers, plant height, and nodes) and physiological (leaf net photosynthetic rate [Pn], stomatal conductance [gs], intercellular CO2 concentration, and leaf water soluble sugar concentrations) characters were determined during the experiment. Responses of sugarcane growth, photosynthesis, and photoassimilate translocation to salinity depended on soil salt concentration. Plant height was the most sensitive while the number of nodes was the most tolerant to soil salinity among the three growth traits measured. CP 96-1252 differed from CP 00-1101 significantly in response of shoot:root ratio to high salt concentration. Leaf Pn of plants treated with the 38 mM salt did not differ from that of the control plant, but plants treated with the 75, 150, and 300 mM salt had 12.7, 18.7, and 35.3% lower leaf Pn, respectively, than the control. The low leaf Pn due to salinity was associated with not only the decrease in gs, but also the non-stomatal factors. Results of leaf sugar composition and concentrations revealed that high salt concentration also depressed photoassimilate translocation from leaves to other plant tissues. These findings are important for better understanding of some physiological mechanisms of salinity influence on sugarcane growth and yields.