Pear rootstocks growing in the tissue culture lab. PHOTOS BY GERALDINE WARNER   A high-tech nursery based in Pullman, Washington, is propagating Washington State University’s new WA 38 apple through tissue culture in anticipation of its commercial release. Phytelligence holds a propagation license for WA 38, which is one of the first varieties to be released by the university’s apple breeding program. Propagating through tissue culture, starting with explants—small pieces of plant tissue—growing in petri dishes, is a much faster way to produce budwood than the traditional method of growing mother trees in the ground, which can take several […]