温度和湿度对草果花柱卷曲的影响

草果（Amomum tsaoko）为姜科植物，有花柱卷曲机制。研究表明温度和湿度均影响草果上举型花和下垂型花的花柱卷曲，相对恒定的低温和高湿可促使花柱的同步卷曲。当8∶00-19∶30期间的平均温度小于18℃、平均湿度大于90%时，花柱卷曲没有滞后现象，卷曲的同步性较好。当平均温度大于18℃、平均湿度小于90%时，随着温度的升高和湿度的降低，花柱卷曲滞后愈加明显。和上举型花相比，下垂型花的花柱卷曲对湿度变化更为敏感；可能两种花型之间存在一定的分化。居群初花期19.17~19.52℃的平均温度和51.00%~51.44%的平均湿度，导致单朵下垂型花的寿命由1d延长为2d。温度和湿度变化对花柱卷曲的影响导致在居群水平上没有完全形成功能上的雌雄异株，可能影响草果的繁育和降低其适合度。从不同角度对花柱卷曲机制的深入研究，有助于更好的探索其起源和进化。

The Influence of Temperature and Humidity on Stylar Curvature in Amomum tsaoko (Zingiberaceae)

Flexistyly is a floral mechanism involving extreme curving of the style first described in Amomum tsaoko Crevost & Lemarie. We examined the influence of temperature and humidity on stylar curvature in this species. Although floral behavior was similar to that reported previously in this species and other flexistylous gingers, there was a delay in stylar movement in two morphs, which differed strikingly from previous observations. When mean temperature and humidity between 8∶30 and 19∶30 hrs were below 18℃ and above 90%, respectively, style movement of both morphs was not delayed; however, there was a delay in style movement when temperature was increased above 18℃ and humidity fell below 90%. Stylar curvature of cataflexistylous flowers was more sensitive to change of humidity than anaflexistylous ones. When mean temperature and humidity were between 19.17-19.52℃ and 51.00%-51.44%, respectively, the anthesis of a single cataflexistylous flower was prolonged from 1 day to 2 days, and stylar curvature downwards was asynchronous. The asynchronous stylar movement did not ensure complete functional dioecy within a population, which would decrease successful cross fertilization (outcrossing) between the two different forms, and affect the breeding and fitness of plants. Flexistyly is a special form of heterodichogamy, which requires further study to fully understand its origin and evolution.