Phenotypic traits of tomato seeds obtained by X-ray microCT imaging predictive of seed germination

The identification of predictive morphological traits of tomato seed quality and their germination has long beenattempted using conventional radiography as a technique to observe internal seed structures and to guide theseed sorting. Many studies observed that the main obtained feature, namely the amount of internal free space,cannot be used alone to predict germination behavior. In addition, the huge variation of the internal structuralabnormalities and structural damages affect germination depending on their extent and localization and theirdetection is not always possible by means of conventional radiography. Although the three-dimensional X-rayimaging has been increasingly common in seed science as allows much more accurate visualization of the internalseed parts, such approach has never been used to analyze tomato seeds. The aim of this work was to test theuse of the X-ray microCT imaging for the identification of phenotypic traits of tomato seeds related to thegermination capacity. A 100 seeds sample was scanned by a X-ray microtomograph and the internal and externalseed traits were quantified using morpho-densitometric parameters. Then a germination test was carried out onthe same seeds whose identity remained traced. The internal fragmentation degree and the Sauter meandiameter resulted as the morpho-densitometric parameters better correlated with not germinated individuals.Although such identified predictive traits are not quite rapidly detectable, further studies could allowidentification of correlations with some external parameters suitable for a rapid determination in a highthroughput sorting system.