ESTIMATION OF PROTEIN CONCENTRATION IN THREE PLANT PARTS AT FOUR GROWTH STAGES IN WHEAT BY NEAR INFRARED REFLECTANCE

Abstract

Near Infrared Reflectance was examined to be used as a technique of estimating protein concentration in the head, flag leaf, and peduncle of Newana, hard red spring wheat (Triticum aestivum L.) at four growth stages. The plant samples were taken from a field experiment including three N levels. The standard Kjeldahl method was used to estimate protein concentration in these plant parts. Protein concentration in these samples ranged from 2.7% in the peduncle to 16.7% in the flag leaf. The NIR was calibrated using these plant parts. Using 3 of 19 available filters the R2 for the calibration between Kjeldahl and NIR was 0.98. The validity of the NIR calibration was tested using an independent set of plant parts of winter wheat taken at three growth stages. The r2 obtained between Kjeldahl and NIR was highly significant. It was concluded that NIR provides an accurate, rapid, and economical technique for estimating protein concentration in aerial plant tissues. This should facilitate the screening of wheats for genotypic variation in aerial plant protein.Key words: Wheat, Kjeldahl N, protein translocation, protein estimation, Triticum aestivum L.