Relative effects of temperature vs. photoperiod on growth and cold acclimation of northern and southern ecotypes of the grass Arrhenatherum elatius
Relative effects of temperature vs. photoperiod on growth and cold acclimation of northern and southern ecotypes of the grass Arrhenatherum elatius
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DOI：
10.1016/j.envexpbot.2014.02.007
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发表时间：
2014-10-01
影响因子：
5.7
通讯作者：
Kreyling, Juergen
中科院分区：
文献类型：
--
作者：
Malyshev, Andrey V.;Henry, Hugh A. L.;Kreyling, Juergen
多年生牧草在秋季的生长代表了生长季节延长和对霜冻的脆弱性增加之间的平衡。在物种内，沿着纬度梯度，植物可能会表现出生态类型特定的敏感性的温度和光周期的线索，影响冷驯化。因此，对于给定的纬度，气候变暖将如何改变冷驯化的时间和程度，从而对霜冻事件的脆弱性尚不清楚。我们评估了两个北方（瑞典）和两个南方（意大利）生态型的普通牧草Arrhytherum elatius在模拟冷驯化过程中的相对温度和光周期敏感性。将三个温度水平（Temp（低）：3 ℃，TeMP高+低：8 ℃，随后3 ℃，和Temp（高）：8 ℃）与2个光周期水平（光（短）：6小时，和光（长）：12小时）交叉，并对植物施用三周的适应期。然后将所有植物在-8 ° C冷冻1天，并在3周后测量霜后生长。温度（高）和光（长）增加霜冻前的增长，但导致霜冻后的增长下降。温度对糖浓度、生物量和花的存在的影响取决于光周期，温度仅在光（短）下影响糖浓度和开花，而光（长）仅在高温下增加生物量。南方A.霜冻前的elatius生态型，结合足够的冷驯化，导致霜冻后较高的生物量积累。南方生态型的快速生长习性可能有利于积累较高的夏季生物量，即使在秋季中度霜冻事件后。(C)© 2014 Elsevier B. V.保留所有权利。
Growth of perennial grasses in the fall represents a balance between an extended growing season and increased vulnerability to frost. Within species along latitudinal gradients, plants may exhibit ecotype-specific sensitivities to the temperature and photoperiod cues that influence cold acclimation. Therefore, it is unclear for a given latitude how climate warming will alter the timing and extent of cold acclimation, and thus vulnerability to frost events. We evaluated relative temperature and photoperiod sensitivities during simulated cold acclimation for two northern (Swedish) and two southern (Italian) ecotypes of the common forage grass Arrhenatherum elatius. Three temperature levels (Temp(low): 3 degrees C, TeMPhigh+low: 8 degrees C followed by 3 degrees C, and Temp(high): 8 degrees C) were crossed with 2 photoperiod levels (Photo(short): 6 h, and Photo(long): 12h) and administered to the plants for a three week acclimation period. All plants were then frozen at -8 degrees C for 1 d, and post-frost growth was measured after 3 weeks. Temp(high) and Photo(long) increased growth prior to frost, but resulted in decreased growth after frost. The effects of temperature on sugar concentration, biomass and flower presence depended on photoperiod, with temperature only influencing sugar concentration and flowering at Photo(short), while Photo(long) increased biomass only at the high temperature. The faster growth rate of southern A. elatius ecotypes before frost, in combination with sufficient cold acclimation, resulted in higher biomass accumulation after frost. The faster growth habit of southern ecotypes may be advantageous in accumulating higher summer biomass even after moderate frost events in the fall. (C) 2014 Elsevier B.V. All rights reserved.