A Comparison of Growth and Sucrose Metabolism in Sugarcane Germplasm from Louisiana and Hawaii
- Sarah E. Lingle *a and
- Thomas L. Tewb
- a USDA-ARS, Southern Regional Research Center, 1100 Robert E. Lee Blvd., New Orleans, LA 70124
b USDA-ARS Sugarcane Research Lab., 5883 USDA Rd., Houma, LA 70360-5578. This research was supported in part by a grant from the American Sugar Cane League. Mention of a trademark or brand name does not imply endorsement by the USDA-ARS
Sugarcane (Saccharum sp. hybrids) genotypes bred in Hawaii are selected for maximum tonnage in a 2-yr production cycle and contain S. robustum germplasm. Genotypes bred in Louisiana are selected for high early sucrose yield after a 9-mo growing season, and contain S. spontaneum germplasm. We compared growth, sugar concentration, and enzymes of sucrose metabolism in four internodes of four Hawaii (HI) and two Louisiana (LA) genotypes during grand growth and ripening. On average, Sucrose concentrations were higher in LA than HI genotypes, especially at ripening. Fresh weight activities of soluble acid invertase (SAI) and neutral invertase (NI) were not different among genotypes at either growth stage. Significant differences in activities of sucrose synthase (SuSy), sucrose-phosphate synthase (SPS), and cell wall acid invertase (CWIN) among genotypes were not consistent between types. Sucrose concentration, total sugar concentration, and sucrose:total sugar ratio in the internodes were negatively correlated with water content, SAI activity, and NI activity, and positively correlated with the difference between SPS and SAI activity. These correlations seem to be a function of internode maturity. The consistent differences in sucrose content between LA and HI genotypes indicate the Louisiana and Hawaii breeding programs have produced very different genotypes, but these differences cannot be explained by differences in enzyme activities.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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