INNOVATIVE TECHNIQUES TO EVALUATE EARLY SEEDLING VIGOUR

Abstract

Seedling vigour, the capacity of a seed lot to produce rapid, uniform, and robust seedlings under a wide range of field conditions, is a critical determinant of crop establishment, yield potential, and ultimately food security. Traditional vigour assays, including the standard germination test, accelerated ageing test, electrical conductivity test, cold test, and tetrazolium test, remain the backbone of seed testing laboratories worldwide, yet they are frequently destructive, labour-intensive, subjective, and slow, limiting their utility for high-throughput breeding and quality-control pipelines. Over the past two decades, an expanding suite of innovative, largely non-destructive technologies has emerged to complement and, in some cases, replace conventional bioassays. This review synthesises recent advances in image-based phenotyping and computer vision, machine learning and deep learning classification, hyperspectral and multispectral imaging, near-infrared and Raman spectroscopy, chlorophyll fluorescence imaging, X-ray radiography and micro-computed tomography, root system architecture phenotyping, thermal imaging and unmanned aerial vehicle (UAV)-based field emergence monitoring, electrophysiological assays, and omics-based biomarker discovery (proteomics, metabolomics, transcriptomics, and epigenomics). The principles, analytical workflows, reported accuracies, crop applications, and comparative strengths and limitations of each approach are discussed, alongside emerging trends in multi sensor data fusion and artificial intelligence-driven decision support. The review concludes by identifying key bottlenecks constraining commercial adoption, including throughput, cost, standardisation, and cross-laboratory reproducibility, and outlines priority research directions for translating laboratory-scale innovations into routine, non-destructive seedling vigour evaluation for the global seed industry.