目的 为紫苏合理栽培和综合利用提供科学依据。方法 从2013年7月5日开始每隔25 d测定1次光合和生长指标。结果 首次建立了紫苏干物质积累的Logistic方程。0～75 d为生长渐增期即苗期；76～84 d为花蕾期，85～95 d为开花期，花蕾期和开花期为快速生长期；96～125 d为生长缓增期即落叶期。叶绿素a、叶绿素b、叶绿素量的变化趋势一致，在开花期达到最高，而后逐渐下降；可溶性蛋白量的降低早于叶绿素量；希尔反应活力、Ca²⁺-ATP酶和Mg²⁺-ATP酶活性均为单峰曲线，均于花蕾期达到最高；苗期光合速率日变化为双峰曲线，但是其他时期的光合速率日变化呈单峰曲线；气孔导度和蒸腾速率的变化趋势一致。结论 紫苏在开花期之前或落叶期之后收获为宜，且在生长速率最快到来之前实施促长措施。

Objective To provide basic theory for rational cultivation and comprehensive utilization of Perilla frutescens. Methods The photosynthesis and growth characteristics were measured every 25 d from July 10th, 2013. Results Logistic equation of dry matter weight was firstly established, and the slightly increasing stage was also called seedling stage (0—75 d); The flower budding stage was 76—84 d, the blooming stage was 85—95 d, and the 20 d was called period of accelerating growth stage; The period of decelerating growth was defoliation period (96—125 d). As was observed both specimens “a” and “b”, chlorophyll content increased and reached the peak value during flower budding before going on a gradual decline, but not before that of soluble proteins. The Hill reaction, as well as Ca²⁺-ATPase and Mg²⁺-ATPase activities all reached the peak values just before blooming began; The photosynthesis rate was at peak twice during seedling stage, which was once more than in any other stage of the growth of Perilla frutescens. Strong positive correlation was observed between stomatal conductance and transpiration rate. Conclusion For maximum yield of leaf, stem, or seed, harvesting should take place either before flowers bloom or after leaves fall. All growth-spurring measures should be implemented before growth rate reaches a zenith or risk not being effective.

国家粮食丰产工程项目（2011BAD16B08S10）；河北省科技支撑计划项目（10225520）；唐山市科技支撑项目（12120202A）