scholarly journals Source–sink relationships during early crop development influence earliness of sugar accumulation in sugarcane

2019 ◽  
Vol 70 (19) ◽  
pp. 5157-5171
Author(s):  
Julio V Saez ◽  
Jorge A Mariotti ◽  
Claudia R C Vega

The dynamics of tiller production and senescence modify early source–sink relationships in sugarcane and the thermal time from crop emergence to the end of the tiller mortality phase appears to be a key trait in identifying earliness of sucrose accumulation.

2010 ◽  
Vol 61 (2) ◽  
pp. 111 ◽  
Author(s):  
N. G. Inman-Bamber ◽  
G. D. Bonnett ◽  
M. F. Spillman ◽  
M. H. Hewitt ◽  
D. Glassop

While substantial effort has been expended on molecular techniques in an attempt to break through the apparent ceiling for sucrose content (SC) in sugarcane stalks, molecular processes and genetics limiting sucrose accumulation remain unclear. Our own studies indicate that limiting expansive growth with water stress will enhance sucrose accumulation in both low- and high-sucrose clones. Sucrose accumulation was largely explained (72%) by an equation with terms for photosynthesis, plant extension rate (PER), and plant number. New research was conducted to determine if this simple model stands when using temperature rather than water stress to perturb the source–sink balance. We also applied a thinning treatment to test the proposal implicit in this equation that SC will increase if competition between plants for photo-assimilate is reduced. Four clones from a segregating population representing extremes in SC were planted in pots and subjected to warm and cool temperature regimes in a glasshouse facility. A thinning treatment was imposed on half the pots by removing all but 6 shoots per pot. Temperature as a means of reducing sink strength seemed initially to be more successful than water regime because PER was 43% lower in the cool than in the hot regime while photosynthesis was only 14% less. PER was a good indicator of dry matter allocation to expansive growth, limited by water stress but not by temperature, because stalks tended to thicken in low temperature. Thinning had little effect on any of the attributes measured. Nevertheless the clonal variation in plant numbers and the response of PER to temperature helped to explain at least 69% of the variation in sucrose accumulation observed in this experiment. Thus the earlier model for sucrose accumulation appeared to be valid for the effect on sucrose accumulation of both temperature and water stress on the source–sink balance. The next step is to include internodes in models of assimilate partitioning to help understand the limiting steps in sucrose accumulation from the basics of source–sink dynamics.


Agriculture ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 136 ◽  
Author(s):  
Nguyen ◽  
Dang ◽  
Nguyen ◽  
Tran ◽  
Giang ◽  
...  

The use of plant growth regulators is one effective solution to improve sugarcane yields and sugar content in several countries. In this study, we examined the role of gibberellin acid (GA3) and glyphosate (Gly) plant growth regulators to determine the appropriate concentration of GA3 and Gly to increase the yield of sugarcane and sugar accumulation, respectively. The statistical results showed that GA3 was sprayed at 150 ppm to increment the actual yield by 19.94%; sucrose accumulation increased by 2.21%. With Gly treatment, although the yield decreased by 3.17%, sucrose accumulation increased by 11.27% compared to control trials. In this study, the combined concentration of 150 ppm of both GA3 and Gly gave the best results, for which sucrose accumulation increased from 2.21% to 10.74% and from 19.94% to 20.97% for actual yield. The results led to increased net income compared to the control. To address concerns about residues of plant growth regulators, residues of GA3 and Gly were evaluated after the sugarcane harvest using the HPLC and UV-vis methods, respectively. The analyzed results showed that their residues were lower than what is permitted in several countries. This showed the applicability of the study, on a large scale, to increase sucrose accumulation, productivity of sugarcane, and profit for farmers.


HortScience ◽  
2008 ◽  
Vol 43 (3) ◽  
pp. 792-794 ◽  
Author(s):  
Yasutaka Kano ◽  
Youichi Ikeshita ◽  
Yuri Kanamori ◽  
Nobuyuki Fukuoka

To investigate the effects of night temperature on sugar accumulation in watermelon fruit, fruits were treated with higher nighttime temperature under a greenhouse. The minimum nighttime ambient temperature of the heating box (18 °C) was ≈6 °C higher than that of the control. The heat-treated fruit weighed at the end of heating treatment, 16 days after anthesis (DAA), was greater than that of control, but fruit weight at harvesting, 42 DAA, was almost the same in both treatments. Cells of all portions of the heat-treated fruit at 16 DAA were much larger than those of the control, and cells in the outermost rectangular parallelepipeds (RPs; 15-mm long samples that were serially collected from a 10-mm thick disk along a 10-mm wide strip removed at the maximum transverse diameter of the fruit) of the heat-treated fruit were 80 μm or more larger than those of the control. At 16 DAA, the number of RPs with sucrose contents of 2 g·L−1 or more were six and nine in control and heat-treated fruit, respectively. At 42 DAA, content in the outer RPs of the heat-treated fruit was greater than that in the outer RPs of the control. The number of RPs with sucrose contents of 40 g·L−1 or more was five in the control and 11 in heat-treated fruit. Mean sucrose, glucose, and fructose in fruit at 16 DAA did not differ in the treated fruit from the control. However, the sucrose content of heat-treated fruit was 32% higher than that of the control at 42 DAA. Glucose and fructose content were lower in heat-treated fruit than in the control.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Jason P. Smith ◽  
Everard J. Edwards ◽  
Amanda R. Walker ◽  
Julia C. Gouot ◽  
Celia Barril ◽  
...  

Abstract Background Elucidating the effect of source-sink relations on berry composition is of interest for wine grape production as it represents a mechanistic link between yield, photosynthetic capacity and wine quality. However, the specific effects of carbohydrate supply on berry composition are difficult to study in isolation as leaf area or crop adjustments can also change fruit exposure, or lead to compensatory growth or photosynthetic responses. A new experimental system was therefore devised to slow berry sugar accumulation without changing canopy structure or yield. This consisted of six transparent 1.2 m3 chambers to enclose large pot-grown grapevines, and large soda-lime filled scrubbers that reduced carbon dioxide (CO2) concentration of day-time supply air by approximately 200 ppm below ambient. Results In the first full scale test of the system, the chambers were installed on mature Shiraz grapevines for 14 days from the onset of berry sugar accumulation. Three chambers were run at sub-ambient CO2 for 10 days before returning to ambient. Canopy gas exchange, and juice hexose concentrations were determined. Net CO2 exchange was reduced from 65.2 to 30 g vine− 1 day− 1, or 54%, by the sub-ambient treatment. At the end of the 10 day period, total sugar concentration was reduced from 95 to 77 g L− 1 from an average starting value of 23 g L− 1, representing a 25% reduction. Scaling to a per vine basis, it was estimated that 223 g of berry sugars accumulated under ambient supply compared to 166 g under sub-ambient, an amount equivalent to 50 and 72% of total C assimilated. Conclusions Through supply of sub-ambient CO2 using whole canopy gas exchange chambers system, an effective method was developed for reducing photosynthesis and slowing the rate of berry sugar accumulation without modifying yield or leaf area. While in this case developed for further investigations of grape and wine composition, the system has broader applications for the manipulation and of study of grapevine source-sink relations.


2016 ◽  
Vol 96 (5) ◽  
pp. 765-775 ◽  
Author(s):  
Manasah Mkhabela ◽  
Guy Ash ◽  
Mike Grenier ◽  
Paul Bullock

Predicting crop development stages is fundamental to many aspects of agronomy (e.g., pesticides and fertilizer applications). Temperature is the main factor affecting plant development and its impact on crop development is often measured using thermal-time. We compared different thermal-time models to identify the best model for simulating spring wheat development in western Canada. Models compared include (i) North-Dakota growing-degree-day (NDGDD), (ii) growing-degree-day base-temperature zero (GDD0), (iii) growing-degree-day base-temperature five (GDD5), (iv) beta-function (BF), and (v) modified-beta-function (MBF). We utilised agro-meteorological data collected across western Canada from 2009–2011. Results showed that accumulated heat units/daily growth rates from the different models correlated well with spring wheat phenology with R2 ≥ 0.91 and P < 0.001. However, when the developed models were used to predict time (calendar-days) from planting to anthesis for cultivar AC-Barrie, the BF and MBF models performed poorly. Average predicted times from planting to anthesis by NDGDD, GDD0, GDD5, BF, and MBF models were 63, 63, 62, 65, and 64 d, respectively; while the actual observed time was 60 d. Root-mean-square error (RMSE) for NDGDD was 4 d, 5 d for GDD0 and GDD5, and 6 d for BF and MBF. These findings suggest that simple GDD-based models performed better than more complex BF-based models.


2010 ◽  
Vol 32 (4) ◽  
Author(s):  
Leonardo Bianco Carvalho ◽  
Caio Dória Guzzo ◽  
Robinson Antonio Pitelli ◽  
Arthur Bernardes Cecílio Filho ◽  
Silvano Bianco

1990 ◽  
Vol 115 (5) ◽  
pp. 798-802 ◽  
Author(s):  
Natalie L. Hubbard ◽  
D. Mason Pharr ◽  
Steven C. Huber

Muskmelon (Cucumis melo L.) fruit lack a stored starch reserve and therefore depend on translocated photoassimilate from the leaf canopy for sugar accumulation during ripening. The influence of canopy photosynthesis on sucrose' accumulation within muskmelon fruit mesocarp was examined. Canopy photosynthetic activities were estimated in a sweet and a nonsweet genotype. Photosynthetic rate of the nonsweet genotype, on a per-plant basis, was only 56% of that of the sweet genotype. The effect of limiting leaf area of the sweet genotype on carbohydrate concentrations and sucrose metabolizing enzymes within the fruit was evaluated. A 50% reduction of leaf area 8 days before initiation of fruit sucrose accumulation resulted in canopy photosynthesis similar to that of the nonsweet genotype. Reduced photosynthetic activity resulted in slightly lower soluble-carbohydrate concentration in the fruit; however, fruit sucrose concentration was three times higher than that reported previously for the nonsweet genotype. The extent to which `fruit sucrose phosphate synthase (SPS) activity increased during maturation was diminished by leaf removal. Acid invertase activity declined in all fruit in a similar manner irrespective of defoliation. A reduction of leaf area of a sweet genotype reduced sucrose accumulation within the fruit. Lower fruit sucrose concentration was associated with lower concentration of raffinose saccharides and lower SPS activity within the fruit. Additionally, insufficient assimilate supply was judged not to be the factor responsible for low sucrose accumulation in a nonsweet genotype.


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