Arbuscular mycorrhizae in Paris polyphylla var.yunnanensis VEGETATIVE PROpAGATION OF PARIS POLYPHYLLA VAR.YUNNANENSIS Chemical constituents from rhizome of Paris polyphylla var.yunnanensis EFFECT OF COLD TREATMENT ON PLOIDY OF MICROSPORE IN PARIS POLYPHYLLA VAR. YUNNANENSIS STEROID SAPONINS OF AERIAL PARTS OF PARIS POLYPHYLLA VAR. YUNNANENSIS