Abstract:

This study aimed to provide a basis for the evaluation of germplasm resources, variety classification and identification, and selection of excellent varieties for Lonicera japonica based on submicroscopic structure characteristics of pollen grains. Optical microscope and scanning electron microscope were used to classify and identify the plants, stems, leaves, flowers, pollens, and outer ornamentations of L. japonica varieties. The data were analyzed using statistical product and service solutions(SPSS). There were certain differences in the morphological traits, pollen shapes, germinal apertures, and outer ornamentations of the eight L. japonica varieties. The stem and crown of the Sijihua plants were obvious, and the Beihua No.1 plants were bush-like. The buds of L. japonica No. 24 were sparsely pubescent. The pollen grains were spheres, with dense thorn-like ornamentations on the outer wall. The pollen grains of Beihua No.1 and Sijihua were triangular spheres, with dense, thick, thorn-like ornamentations on the outer wall. The stems, branches, and buds of Damaohua had dense, long pubescence. The buds of L. japonica No. 16 were densely covered, with glandular hairs and acicular hairs. The pollen grains of L. japonica No. 1, L. japonica No. 15, and L. japonica No. 23 were blunt triangular spheres or spheroids, with sparse, thorn-like ornamentations on the outer wall. The morphological characteristics of the pollen grains of L. japonica varieties provide a palynological basis for variety classification and identification.

Key words: Lonicera japonica Thunb., variety, pollen grains, colporate, scanning electron microscopy