Know your plants with FT-NIR

Fourier-Transform (FT) NIR data should be collected for as many plant species as possible, say Brazilian and US scientists. This follows their discovery that FT-NIR spectroscopy can discriminate between even closely plant species more accurately than DNA fingerprinting.

Conventionally, plant species are identified by studying their flowers or fruits, which is a time-consuming process that requires a great deal of expertise. More recently, scientists have tried using DNA fingerprinting to identify plant species. Unfortunately, plants tend to lack the easy-to-detect, species-specific DNA markers found in animals and so the whole process is not particularly accurate, with researchers reporting success rates of less than 70% for closely related species.

Perhaps NIR spectroscopy could prove more successful. Already, a couple studies have indicated that FT-NIR spectroscopy can accurately distinguish between closely-related plant species, based on differences in the polysaccharide, lipid and protein compositions of their leaves. Now, in a larger scale study, a team of scientists from the US and Brazil, led by Albert Vicentini at the Instituto Nacional de Pesquisas da Amazônia, have used FT-NIR spectroscopy to distinguish between 10 different plant species from the Amazon.

In a paper in Forest Ecology and Management, Vicentini and his team report analysing 159 leaf samples from 10 different plant species, comprising two species from the Corythophora genus and eight species from the Eschweilera genus, including some of the most common tree species in the Amazon. Producing models from this FT-NIR data, the scientists found that they could identify the 10 plant species with an accuracy of over 96% from just one spectral reading. This accuracy could be increased to 99% by simply increasing the number of readings and analysing both the top and bottom of intact leaves.

Even more impressively, the scientists also found that the NIR spectra tended to differ more between more distantly related species, suggesting that FT-NIR data can also be used to determine evolutionary relationships between plant species. Even more reason to start analysing plant collections with FT-NIR spectroscopy.

Blog tags: