Grain Size Distribution and Head Rice Yield of Some Rice Breeding Lines using Flat-Bed Scanning and Digital Image Analysis

Naela V. Delmo1, Arvin Paul P. Tuaño2, and Ernesto J. del Rosario1,2,*

1Institute of Chemistry, College of Arts and Sciences,
University of the Philippines Los Baños, Laguna, Philippines
2National Academy of Science and Technology Philippines

https://doi.org/10.57043/transnastphl.2021.1128

ABSTRACT

Rice grain quality evaluation is crucial in rice breeding and  production of selected varieties. Characterization of rice grain  fractions after milling is important; these include brown rice,  milled rice, and head rice yield (HRY). The latter is the main  determinant for the market price of rice. The present study aims  to utilize image analysis as a tool for assessing HRY. Digital image  analysis (DIA) was used to quantitatively determine HRY for  eight selected rice breeding lines and the results were compared  with those obtained by the conventional method of manual  inspection (MI). Digital images of the rice grains were taken  with a flat-bed scanner (FBS) and analyzed using free-access  software (ImageJ). Areas of individual grains were determined,  and percent grain area was calculated in terms of the ratio of  actual-to-whole grain areas (AWGA). Size grain distribution plots  were generated per breeding line, and those grains with values  of the AWGA ratio greater than or equal to 75% were classified  as head rice. The HRY value was calculated in percent-by-mass  basis using the mass of 100 whole rice grains. Values of HRY  obtained using DIA showed no significant difference compared  to those obtained using the conventional method. This was  done according to the paired samples t-test at 95% confidence  interval, which showed a high correlation coefficient (R2 = 0.99).  The DIA method showed good repeatability and reproducibility  based on different precision parameters indicating its potential  as a practical, inexpensive, and quantitative method for  determining HRY of rice breeding lines.  

*Corresponding Author: ejdros@yahoo.com