Selection of crown type provides a potential to improve the content of isorhamnetin in Ginkgo biloba.

• The wide-crown medium type favors the tree height growth and leaf yield. • Crown types significantly affects isorhamnetin contents. • Selection of a wide-crown medium type will increase active substance contents. Ginkgo (Ginkgo biloba L.) has attracted much attention due to its medicinal properties, such as its high flavonoid and lactone contents. To improve its content of active substances through phenotypic selection, variation in crown type and its association with the main active substance contents were investigated at four test sites. The results showed significant differences in the tree height (HT), diameter at breast height (DBH), branching angle (BA), leaf area (LA), and leaf density among the crown types. The results also indicated that the isorhamnetin contents in Ginkgo leaves differed significantly among the crown types and tended to increase with increasing crown size, suggesting the effectiveness of the classification in crown types and its potential use in selective breeding. Trees with the wide-crown medium type had the highest growth rate in HT and DBH, and the greatest leaf yield. Selection of wide-crown medium types will greatly increase active substance contents, but selection of individuals whose crown type has a high content is also necessary to fully exploit the variation among Ginkgo individuals and enhance breeding efficiency. This study will provide a basis and effective method for selection, breeding, and industrial production. [ABSTRACT FROM AUTHOR]