Abstract:

The study of downiness of Hippophae rhamnoides L. subsp. sinensis Rousi is intended to clarify the chaos of definitions of different downiness, approachs the morphology and evolutionary relationships among downiness groups which provides a reasonable basis for the toxonamy, ecology and system evolution of Hippophae. Observed under light microscope and scaning electron microscopes, two types and six groups of downiness of Hippophae rhamnoides subsp. sinensis are indentified. The first type is spiral downiness, including spiral stellate, spiral stellate-peltate and spiral peltate downiness groups; The second non-spiral downiness, including stellate, stellate-peltate and peltate downiness groups. In systematic development, stellate peltate downiness, derived from stellate downiness, developsinto peltate downiness, and spiral downiness are derived from non-spiral downiness. Therefore, stellate and spiral stellate downiness are primitive character type; stellatepeltate and spiral stellatepeltate downiness are derived type; peltate and spiral peltate downiness are evolutionary type. In ontogeny, stellate and spiral stellate downiness generate first, stellate-peltate and spird stellate and spiral stellate downiness second, and then peltate and piral peltate downiness. The main function of the downiness of Hippophae mainly is to protect the buds overwintering.

Key words: Hippophae rhamnoides subsp. sinensis, Downiness, Morphology, Calssification, Function