1. A method of three-dimensionally imaging an apical dome of a plant embryo, comprising: obtaining three-dimensional information of the apical dome of the plant embryo with an image detector or a spectrometer; ascertaining at least one morphological feature of the apical dome based on the obtained three-dimensional information with image recognition and/or analysis software running on a computer; and classifying the plant embryo according to its putative germinant vigor based on the at least one ascertained morphological feature of the apical dome with a classification algorithm running on a computer, wherein the at least one morphological feature is selected from the group consisting of apical dome size, apical dome volume, apical dome shape, apical dome symmetry, apical dome color, and apical dome surface texture.