Rapid measurement of total non-structural carbohydrate concentration in grapevine trunk and leaf tissues using near infrared spectroscopy

Carbohydrate assays are commonly used in crops and plant research to understand the way in which carbohydrates are allocated within the vine and to assess its influence on the physiology and phenology of the plant. Total non-structural carbohydrate (TNC) concentration is normally assessed by wet chemistry methods which are time consuming and costly, especially when studying carbohydrate dynamics over seasons. Near infrared (NIR) spectroscopy is a fast and easy technique that has lately gained wide acceptance for the analysis of the chemical composition of grain, food, wine, pharmaceutical products, among others. Near infrared is the region of the electromagnetic spectrum between 750 nm and 2500 nm and it is used to gather information on the relative proportions of C[sbnd]H, N[sbnd]H and O[sbnd]H bonds of the organic molecules. This study collected NIR spectra from grapevine trunk and leaf tissues, measured TNC concentration of the same samples using a wet chemical method and compared the results using multivariate data analysis to develop a rapid procedure for the estimation of TNC concentration in grapevine tissues. Results showed that NIR spectroscopy could be used to predict starch and TNC concentration in freeze-dried and ground grapevine trunk and leaf tissues. Moreover, it has been demonstrated that a robust universal model could be applied to the prediction of TNC in both leaves and trunks. Therefore, this method could be used as a practical tool for a rapid screening of TNC concentration for high temporal and spatial assessment of grapevine tissues at given phenological stages. The main advantages of this technique over traditional methods are the rapidity and the ease-of-use protocol in routine analysis, which allows a considerable reduction of costs and time.