The development of automated analysis algorithms for characterizing wheat seeds'morphological traits and internal components using multispectral imagery
The increasing global climate change is impacting wheat(Triticum aestivum)production,a sta-ple crop that is key to ensure China's food security.In order to safeguard wheat seed quality and vigor for better crop performance,it is important to assess seed morphological features and internal contents reli-ably and at a large scale,resulting in the importance of rapid and non-destructive seed analysis and the necessity of advancing analytical methods in this research domain.In the study presented here,we have combined multispectral seed imaging,computer vision and automated image processing techniques to address methodological problems in seed phenotyping and seed-based phenotypic analysis in terms of throughput and accuracy.We have developed an automated algorithm that can segment individual seed from hundreds of wheat seeds acquired by multispectral imaging device,through which morphological traits(e.g.seed area,length,width,and roundness)and internal components(e.g.plant pigments,starch,vegetable oil and water content,etc.)can be quantified.We have selected 15 wheat varieties and per-formed correlation analysis between computational results of morphological traits and manual measures for 1 347 wheat seeds,resulting in coefficient of determination(R2)0.900 for area(RMSE=1.504),0.981 for length(RMSE=0.188),and 0.911 for width(RMSE=0.795),P<0.001;also,the R2 of six key spectral band-widths between computational and manual scoring for 513 seeds were 0.973,0.970,0.983,0.953,0.891,0.893,with P<0.005.Then,we utilized morphological and spectral traits in clustering and principal compo-nent analysis,establishing a classification method to differentiate wheat seed varieties;finally,we ex-plored several important agronomic traits at the seed level,including seed coating damage and embryo.Hence,we believe that the methods described here provide new approaches for high-throughput seed phe-notyping,enabling biological discoveries with regards to seed quality and vigor studies.