桃芽休眠的自然诱导因子及钙在休眠诱导中的作用

以2年生低需冷量设施栽培适宜品种“春捷毛桃”为试材，研究桃植株进入休眠和发展抗冻性的自然诱导因子及Ca²⁺在此过程中的作用.结果表明：短日照和自然低温单个因子或其共同作用均能诱导桃植株停止生长，然后进入休眠状态和发展抗冻性，但短日照和自然低温的作用机制不同.短日照首先诱导桃植株进入休眠状态，然后诱导抗冻性发展；而自然低温则是首先诱导桃植株抗冻性发展，而后诱导其进入休眠状态；当短日照和自然低温共同作用即自然条件下时，短日照起主导作用，自然低温起辅助促进作用.短日照处理研究表明，短日照诱导桃植株停止生长、休眠诱导和抗冻性发展离不开Ca²⁺的作用，在此过程中Ca²⁺起着传递短日照信号的作用；在人工补光长日照条件下，随着温度的降低，Ca²⁺逐渐由细胞间隙、细胞壁和液泡流入细胞质和核内，同时植株生长速度变缓并最终完全停止，随后进入休眠状态并发展抗冻性.表明Ca²⁺作为传递自然低温信号的信使在自然低温诱导桃植株停止生长、抗冻性发展和休眠过程中起着重要作用.

Natural inducing factors of peach bud dormancy and roles of Ca2+ in the dormancy inducetion.

Taking two-year-old peach tree of cv ‘Chunjie’ as test material, the natural inducing factors of peach bud dormancy and the roles of Ca²⁺ in the dormancy induction were studied. The results revealed that peach plant was very sensitive to short sunlight and/or natural low temperature. These two factors could induce growth cessation, dormancy, and freezing-resistance development, but their action mechanisms differed with each other. Short sunlight induced the dormancy first and the freezing-resistance then, whereas natural low temperature was in adverse. In case of the co-function of short sunlight and low temperature, i.e., under the natural condition, short sunlight was the main factor inducing growth cessation, dormancy, and freezing-resistance development, while natural low temperature was the secondary one. The inducement effect of short sunlight was closely related to the actions of Ca²⁺, because Ca²⁺ played a messenger role in the signal transduction of short sunlight. In the experiment of supplemental light, it was found that with the decrease of temperature, the Ca²⁺ had an increasing influx from the vacuole, intercellular space, and cell wall to the cytosol and nuclei. At the same time, plant growth slowed down and finally ceased, dormancy started then, and freezing-resistance developed, which indicated that as a messenger in the signal transduction of natural low temperature, Ca²⁺ played an important role in the inducement of growth cessation, dormancy, and freezing-resistance development by natural low temperature.