Rapid analyses of dry matter content and carotenoids in fresh cassava roots…

… using an ASD Vis/NIRS spectrometer

Cassava is a main staple for over 800 million people around the world. Ugochukwu Ikeogu with Cornell University’s College of Agriculture and Life Sciences, conducts research on high throughput phenotyping and genomics-assisted breeding for quality traits in cassava. Ugochukwu is part of the NEXTGEN Cassava project funded by the Bill and Melinda Gates Foundation, and UK Aid has recently published his research work, involving the use of a portable visible-near-infrared (Vis/NIRS) ASD QualitySpec Trek instrument.

Case study

In the PLOS One online publication, “Rapid analyses of dry matter content and carotenoids in fresh cassava roots using a portable visible and near infrared spectrometer (Vis/NIRS),” Ugochukwu details his study involving the development of calibration models for dry matter content (DMC) and carotenoids in fresh cassava roots using the ASD portable Vis/NIRS system.

“In cassava breeding, the adoption of new breeding methods such as genomic selection has necessitated standardized, accurate and high throughput phenotyping protocols for efficient improvement, especially complex traits. Availability of phenotyping tools for rapid and large-scale screening of materials, particularly at early stages of cassava breeding will reduce the loss of important genetic information and facilitate the breeding of end-user and farmer-preferred varieties.” … “Obtaining a good relationship between calibrations from processed (mashed) and intact samples could enable field-based screening of materials on different important traits leading to an overall reduction of breeding time and cost.”

In this study, the effects of eight data pre-treatment combinations on calibration models and the relationship between calibrations on processed and intact root samples were examined. The Vis/NIRS derived-DMC was compared to standard oven-drying and a commonly used gravitational phenotyping method. Robust calibration models were developed using Vis/NIRS device even though, the choice of pre-processing and sampling methods can affect the calibration performance. Compared to other methods, Vis/NIRS-derived DMC was highly correlated (0.95 and 0.98 from intact and processed roots, respectively) with the ideal oven-drying as against 0.49 correlation between specific gravity and oven-drying. There was equally a high correlation (0.94) between the intact and processed Vis/NIRS DMC. Therefore, it was concluded that the portable Vis/NIRS could be employed for the rapid analyses of DMC and quantification of carotenoids in cassava for nutritional and breeding purposes.

“NIRS technique is rapid and cost-effective. It is a good alternative for quality and unbiased evaluation of traits especially in low-cost breeding programs, where standard laboratories are not available or their operation is hampered by factors such as poor infrastructure and lack of highly skilled experts. In addition to being a non-destructive analytical tool that only requires minimal sample preparation, the portable [ASD QualitySpec Trek] is very useful in direct field analyses and will further reduce sample degradation.

It is believed that the investment in [Vis/NIRS] is cheaper than the establishment of many protocols for laboratory analyses of different traits, which in most cases are slow, costly and impractical for large-scale screening in plant breeding and nutritional quality analyses.” … “The handheld Vis/NIRS has great potential for standardized and unbiased analyses of traits in cassava breeding. It provides a good alternative for the evaluation and improvement of conventional and novel traits which otherwise, would have been difficult or costly to measure.”

Malvern Panalytical’s ASD QualitySpec Trek is a hand-held, full-range (350-2500 nm), portable spectrometer that delivers accurate spectral results in seconds. By optimizing spectral collection workflow, portability, and ease of use, the ASD QualitySpec Trek saves time in the field and maximizes research budget investment.