Predicting germination of Medicago sativa and Onobrychis viciifolia seeds by using image analysis

Abstract

IntroductionThe ultimate object of testing for germination is to gain information with respect to the field planting value of the seed and to provide results that can be used to compare the value of different seed lots (ISTA, 2005). However, the standard germination test often overestimates actual field emergence (Hampton, 2009). The major reason for this overestimation is that germination tests are conducted under conditions that are more favorable than typically encountered in the field. In order to provide a more accurate appraisal of seed quality for estimating field emergence, the concept of seed vigor was established to measure the quality of a seed lot, based on sampled observations of seedling growth (Sako et al., 2002).Vigor testing not only measures the percentage of viable seeds in a sample; it also reflects the ability of those seeds to produce normal seedlings under the less-than-optimum or adverse growing conditions that may occur in the field (ISTA, 2005). Low-vigor lots having poor field emergence may not necessarily be detected by standard germination (Demir and Mavi, 2008). Demir (2007a, 2007b) identified that vigor test regimens correlated well with field emergence potential.Although vigor testing provides useful information, most vigor tests are time-consuming and costly, and they produce variable results from laboratory to laboratory (Sako et al., 2002). In plants that have small seeds, such as Medicago sativa and Onobrychis viciifolia, these problems are serious and have prevented the widespread, standardized use of seed vigor testing. The vigor tests that have been proposed can be grouped into 3 categories (Bennett, 2002): stress tests (e.g., cold test, accelerated aging), biochemical tests (e.g., electric conductivity, tetrazolium test), and germination evaluation and seedling growth tests (e.g., first count of the germination test, normal seedling emergence in peat, image analysis).Accelerated aging is one of the 2 frequently used ISTArecommended vigor tests (

Machine vision based alternative testing approach for physical purity, viability and vigour testing of soybean seeds (Glycine max)

“…The seed samples possessing low-vigor exhibit poor field emergence (Behtari et al 2014). Demir and Mavi (2008) reported that the low vigour condition of the seeds might not necessarily be detected by standard germination tests.…”

Image Analysis: A Modern Approach to Seed Quality Testing

“…Delta-T© (Delta-Instrumental Device-Cambridge, UK) image analysis system is an another example which was used by Vijaya Geetha et al [8]; Sumathi and Balamurugan [9] with the help of custom written software ''WinDIAS' [10] for characterization of mustard and oat respectively by measuring variation in seed morphology. Behtari et al [11] used ImageTool V.3.0 software point tools to extract, independently, the RGB components of the pixels representing the seed images taken by a digital camera and then manually the intensity of each color component was measured. The relation between the RGB density values and the vigor of Medicago sativa and Onobrychis viciifolia seeds was modeled by combining information obtained from germination experiments and image analysis.…”

“…With the help of this technique, germinated and non-germinated seeds can be easily distinguished and moreover, seed characteristics such as radicle length and seed area can also be measured. Behtari et al [11] used image analysis system for predicting germination of Medicago sativa and Onobrychis viciifolia seeds. In this study, images were processed by a computer to generate numerical red-green-blue (RGB) density values.…”

Assessment of seed quality using non-destructive measurement techniques: a review

“…In recent years, non-destructive techniques, mainly spectroscopy and hyperspectral imaging, have been widely used to predict seed viability (Table 4). A machine vision system was used to predict alfalfa and sativa seed germinability using the RGB (red, green, blue) density value with correlation coefficients of 0.982 and 0.984 for alfalfa and sativa, respectively (Behtari et al ., 2014). Researchers have also studied soybean and snap bean seed germinability using electric impedance spectroscopy in the frequency range of 60 Hz to 8 MHz (Vozáry et al ., 2007).…”