摘要
利用稳定碳同位素比技术与光合速率的测定 ,比较了高、中、低磷素利用效率共 8个小麦品种的水分利用效率 ( WUE)与光合作用特性。土壤干旱条件下 ,叶片宽度和单叶干重显著减少 ,δ13C值提高约 2‰ ,光合速率降低 16%～ 75% ,长期的水分利用效率增大 2 .3～ 3.0μmol/ mmol,因磷效不同而异。高磷效的小麦的δ13C和对 13C的分馏率Δ值较低 ,不论在正常的田间土壤水分或干旱下 ,其瞬时的水分利用效率或长期的水分利用效率皆高于磷效中等或低磷效的品种。正常条件下品种间的光合速率 ( Pn)差别不大 ,干旱下则高磷效品种可保持 68%～ 84 %的 Pn,而低磷效小麦的 Pn 只为其对照的2 5%～ 4 9%。小麦种子的 Δ值与单株籽粒重呈负相关性 ,r2 =- 0 .7184。高磷效的冀 87- 4 617是供试小麦中 Pn 和 WUE最高的品种。
Photosynthetic rate, Water use efficiency and leaf wideness were compared among eight wheat varieties differing phosphate use efficiency by using stable carbon isotope technique and portable photosynthetic apparatus. Under water stress conditions, leaf wideness, dry weight per leaf and net photosynthetic rate (P n) decreased considerably, while δ 13 C value increased 2‰ and the integrated water use efficiency increased 2.3~3.0 μmol/mmol, which depends on the genotypes of wheat. Less δ 13 C and isotope discrimination (Δ) were found in wheat varieties with high phosphate use efficiency (PUE), and their instantaneous or integrated water use efficiency (WUE) were higher than in the cultivars with middle nad low PUE under both normal or drought soil conditions. No obvious differences of P n among tested varieties at normal field water condition was observed, whereas the relative decrease caused by water deficit was 16%~32% of the correspondent control in high PUE varieties, and it was declined by 51%~75% in low PUE varieties. The Δ value was negative related to grain weight per plant (r 2=-0.7184). Variety Ji 87 4617 with high PUE showed the highest P n and WUE under two cases of two soil water status.
出处
《作物学报》
CAS
CSCD
北大核心
2000年第5期543-548,共6页
Acta Agronomica Sinica
基金
中国科学院特别支持项目KZ957-02资助
