Seasonal course of total non-structural carbohydrates in the lignotuberous Mediterranean-type shrub Erica australis
Seasonal course of total non-structural carbohydrates in the lignotuberous Mediterranean-type shrub Erica australis
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DOI：
10.1007/s004420100664
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发表时间：
2001-08-01
期刊：
影响因子：
2.7
通讯作者：
Moreno, JM
中科院分区：
文献类型：
--
作者：
Cruz, A;Moreno, JM
在地中海型灌丛中，木质块茎植物经常占主导地位，储存在木质块茎中的总非结构性碳水化合物（TNC）被认为在火灾后的重新发芽中起着重要作用。然而，该器官和其他植物部位的TNC的季节性变化尚未得到适当的评估，特别是在火灾风险期间，在此期间，木质块茎TNC浓度应该是最高的。我们记录的TNC浓度的季节性过程中的茎，lignotubers和根的13个人口的地中海型，lignotuberous，resprorouter灌木埃里卡australis从西班牙中部。同时测量了植物水势，以将水供应的季节性变化与TNC浓度的波动联系起来。全年茎、木质块茎和根中的平均TNC浓度分别为55、73和120毫克/克（-1）干重。根中含有最高的TNC浓度，这是最大的晚春。淀粉浓度下降，在所有的植物部位在春季，当植物积极生长和繁殖。落叶松块茎TNC浓度在初夏最低，在最大火灾风险期间保持相对较低。单糖浓度显着增加，在所有的植物部位在夏季，与植物水势减少。结果表明，东北地区TNC的季节性波动与东北地区TNC的季节性波动密切相关。australis与植物生长和繁殖期有关，也是对压力条件的反应。没有证据表明，TNC的季节性波动可能是一种反应，以确保最高的TNC含量的木质块茎在火灾风险最大的时期。
Lignotuberous plants are frequently dominant in Mediterranean-type shrublands, and total non-structural carbohydrates (TNC) stored in the lignotuber are assumed to play an important role in resprouting after fire. However, seasonal variations in TNC in this organ and other plant parts have not been properly evaluated, particularly in relation to periods of fire risk, during which lignotuber TNC concentrations should be highest. We document the seasonal course of TNC concentrations in the stems, lignotubers and roots of 13 populations of the Mediterranean-type, lignotuberous, resprouter shrub Erica australis from central Spain. Plant water potentials were measured in parallel to correlate seasonal variations in water availability with fluctuations in TNC concentrations. Mean TNC concentrations in stems, lignotubers and roots throughout the year were 55, 73 and 120 mg g(-1) dry weight, respectively. Roots contained highest TNC concentrations, which were maximal in late spring. Starch concentrations decreased in all plant parts during spring, when plants were actively growing and reproducing. Lignotuber TNC concentrations were lowest in early summer, and remained relatively low during the period of maximum fire risk. Monosaccharide concentrations increased significantly in all plant parts during the summer, coinciding with a reduction in plant water potential. We conclude that seasonal fluctuations of TNC in E. australis are related to periods of plant growth and reproduction, and also occur in response to stressful conditions. No evidence was obtained supporting the idea that seasonal fluctuations of TNC may be a response to ensure highest TNC content in the lignotuber during periods with maximum fire risk.