环境因素对新疆不同地区田旋花种子萌发的影响

【目的】研究环境因素对新疆不同地区田旋花种子萌发的影响,为制定有效的杂草防除技术提供理论依据。【方法】通过室内测定,研究温度、盐碱度、干旱、pH值等环境因子对新疆阿拉尔市和新和县两个点田旋花种子萌发的影响。【结果】阿拉尔市、新和县田旋花种子在5～50℃恒温范围内,随着温度的升高发芽率先升高后降低;田旋花种子最低发芽温度为5℃,当温度上升到30～40℃,两个县市的田旋花种子发芽率均达到最大值,种子在15℃/5℃～45℃/35℃的变温条件下均可发芽,且当温度为40℃/30℃时发芽率最高。盐碱胁迫可降低田旋花种子的发芽率,当NaCl浓度大于300 mmol/L或NaHCO₃浓度大于250 mmol/L时,两个县市的田旋花种子不能萌发;同时,田旋花种子的萌发受水势的影响较大,随着水势的增加,田旋花种子的发芽率逐渐降低,当水势达-0.6 MPa时,新和县田旋花种子已不能萌发,当水势达到-1.0 MPa时,阿拉尔市田旋花种子的萌发率仅为2%;pH值5～10,两个县市的田旋花种子均能正常萌发。【结论】室内模拟实验条件下,温度、盐碱和水势均是影响新疆不同地区田旋花种子萌发的关键环境因素,而农田生态系统中,干旱胁迫和pH不是限制田旋花萌发的主要因素。

Seed Germination of Field Bindweed (Convolvulus arvensis L.) from Different Areas of Xinjiang in Response to Different Environmental Factors

【Objective】 To study the influence of environmental factors on the seed germination of the field bindweed (Convolvulus arvensis L.) in different areas of Xinjiang in the hope of providing a theoretical basis for the development of effective weed control techniques. 【Method】Laboratory experiments were conducted to examine the influence of environmental factors, including temperature, salinity-alkalinity, drought and pH, on germination of field bindweed seeds collected from Aral and Xinhe.【Result】Seeds did germinate at 5℃ and had a maximum germination at 30-40℃, followed by a decline in germination at 45 and 50℃. Seeds germinated at alternating temperature regimes from 15℃/5℃ to 45℃/35℃, with maximum germination at the alternating temperatures of 40℃/30 ℃. Germination was reduced by saline and alkaline stresses and no germination occurred at ≥ 300 mM NaCl or ≥ 250 mM NaHCO₃ concentrations. Moreover, germination decreased as water potential became more negative (-0.1 to -1.0 MPa). Seeds from Xinhe area could not germinate at -0.6 MPa and only 2% germination was observed at -1.0 MPa for seeds collected from Aral. However, pH values from 5 to 10 had no significant effect on germination, and pH was not a main factor limiting the seed germination of field bindweed.【Conclusion】Under the condition of laboratory simulation, temperature, saline-alkali and water potential were the key environmental factors affecting the seed germination of field bindweed (Convolvulus arvensis L.) in different areas of Xinjiang, while drought stress and pH were not the main factors restricting the germination in farmland ecosystem