Submitted to: Agronomy Society of America, Crop Science Society of America, Soil Science Society of America Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2007
Publication Date: 11/7/2007
Citation: Lingle, S.E., Tew, T.L., Viator, R.P., Johnson, R.M. 2007. Effect of Recurrent Selection for Sucrose on Growth and Sugar Accumulation in Sugarcane Internodes [abstract]. In: Agronomy Society of America, Crop Science Society of America, Soil Science Society of America, 2007 International Annual Meetings Abstracts, November 4-8, 2007, New Orleans, Louisiana. CDROM.
Technical Abstract: Commercial sugarcane cultivars are complex, polyploid, interspecific hybrids, primarily of Saccharum officinarum and S. spontaneum. Most breeding programs need about twelve years to develop a new cultivar. Since the 1920’s, Louisiana sugarcane breeding programs have used modified recurrent selection to improve sucrose yield, a product of cane yield and juice sucrose content. We were interested in how this recurrent selection program had changed growth and sugar accumulation of sugarcane internodes. In this study, we planted five cultivars from each of seven cycles of recurrent selection for sucrose in a randomized complete block with four replications in November 2004. On 3-4 November 2005 we sampled stalks from five cultivars each in the first and seventh cycles of recurrent selection. Defining the first internode as that below the point of attachment of the leaf with the topmost exposed collar, we sampled the 2nd, 5th, 8th and 11th internodes. The internodes were measured, weighed, freeze-dried, weighed again, and then ground to a 1 mm screen using a Wiley mill. Simple sugars (glucose, fructose and sucrose) were extracted in 80% ethanol and quantified by high performance anion chromatography with pulsed amperometric detection. On average, internodes of the oldest cultivars were longer than internodes of the most recent ones, but the newest cultivars accumulated more sucrose, suggesting that recurrent selection for sucrose has altered the partitioning of assimilate between growth and storage. Internodes of newest cultivars also reached a higher sucrose:total sugar ratio faster than internodes of oldest cultivars. Since this ratio is a major indicator of maturity in sugarcane, the newest cultivars appear to mature faster than the oldest cultivars. We conclude that recurrent selection to improve sucrose yield has had fundamental effects on growth and sugar accumulation in sugarcane internodes.