The ecological difference and activating characteristic of ineffective phosphorus of 608 accessions core collection (including 548 accessions landrace and 60 improved varieties) from 5 rice regions and 16 prefectures in Yunnan Province were evaluated when planted in P-deficient (effective P: 0.

253 flue-cured tobacco samples of C3F grade were collected from main tobacco-growing areas in Hunan Province,and total sugar content was determined by continuous flow method and smoke quality was quantitatively assessed to study eco-regional difference of total sugar content and their quantitative correlations with evaluation indices of smoke quality.