烟水对云南松及地盘松种子萌发的影响

Effects of smoke water on seed germination of Pinus yunnanensis and P. yunnanensis var. pygmaea

关键词:  云南松, 地盘松, 烟水, 种子萌发, 生理响应

Key words:   Pinus yunnanensis, Pinus yunnanensis var. pygmaea, smoke water, seed germination, physiological response

摘要:

为探究烟水处理对云南松及其变种地盘松种子萌发、胚生长及生理指标的影响,明确二者响应差异及烟水作为模拟火信号刺激林木生长发育的可行性,该研究以不同浓度的烟水进行种子处理,分析其萌发特性、胚生长状况及相关生理指标的变化。结果表明:(1)烟水处理对两种种子的萌发及生理指标均具有显著浓度效应(P<0.05),呈低促高抑趋势。(2)二者发芽指标均在0.5%浓度时达到峰值,此时云南松发芽率与发芽势较对照(蒸馏水处理)分别提高22.80%和62.54%,地盘松则分别提高12.50%和110.83%。(3)胚生长最优浓度存在物种差异,云南松下胚轴长度与胚根长度在1%浓度时最大(较对照提高31.96%和67.89%),地盘松则在0.25%浓度时最佳(较对照提高18.18%和60.77%)。(4)低浓度烟水还可增强α-淀粉酶、蛋白酶、脂肪酶的活性,提高可溶性糖和可溶性蛋白的含量,降低丙二醛含量,改善种子代谢和抗氧化能力。(5)云南松种子对烟水的敏感性高于地盘松种子。综上所述,低浓度的烟水可通过增强贮藏物质转化并调控抗氧化系统促进萌发与胚生长,可作为安全可控的模拟火信号应用于苗木培育。

Abstract:

This study aimed to explore the effects of smoke water treatment on seed germination, embryo growth, and physiological indices of Pinus yunnanensis and its variety P. yunnanensis var. pygmaea, and to clarify their response differences and the feasibility of using smoke water as a fire signal mimic to stimulate tree growth and development. Seeds of two pines were treated with smoke water of different concentrations, and changes in their germination characteristics, embryo growth status, and related physiological indices were analyzed. The results were as follows:(1)The germination and physiological indices of two species seeds were significantly affected by the concentration of smoke water(P<0.05), showing a trend of promotion at low concentrations and inhibition at high concentrations.(2)The germination indices of two species peaked at 0.5%, at which the germination rate and germination energy of P. yunnanensis increased by 22.80% and 62.54%, respectively, while those of P. yunnanensis var. pygmaea increased by 12.50% and 110.83%, compared with control(distilled water treatment).(3)Two species differed in the optimal smoke water concentration for embryo growth. The longest hypocotyl and radicle of P. yunnanensis were observed at 1%(increased by 31.96% and 67.89%, respectively, compared with control), while those of P. yunnanensis var. pygmaea were observed at 0.25%(increased by 18.18% and 60.77%, respectively, compared with control).(4)At low concentrations, the smoke water enhanced the activities of α-amylase, protease, and lipase, increased soluble sugar and soluble protein contents, and reduced malondialdehyde content, thereby improving seed metabolism and antioxidant capacity.(5)P. yunnanensis seeds showed higher sensitivity to smoke water than P. yunnanensis var. pygmaea seeds. In conclusion, the smoke water promotes seed germination and embryo growth at low concentration by enhancing the mobilization of storage substances and regulating the antioxidant system, and thus can be applied as a safe and controllable fire signal mimic for seedling cultivation.