低温锻炼期光周期对笃斯越橘脂肪酸和碳水化合物含量的影响

利用气质联用法和高效液相色谱法研究低温锻炼期不同光周期处理对笃斯越橘(Vaccinium uligiuosum L.)枝条脂肪酸和碳水化合物含量影响,探究抗冻性与脂肪酸和碳水化合物含量关系,阐明抗冻性形成生理生态机制。文章以3年生笃斯越橘苗为材料,将苗木分别置于4℃低温下短日照(10 h)和长日照(14 h)人工环境,处理21 d后测定枝条相对电导率、脂肪酸、可溶性糖及淀粉含量。结果表明,低温和短日照共同作用显著降低饱和脂肪酸含量,提高总不饱和脂肪酸比例和脂肪酸不饱和度。硬脂酸含量和脂肪酸不饱和度与抗冻性有关。低温锻炼期蔗糖、葡萄糖、果糖和总可溶性糖含量显著提高,主要与低温诱导作用有关,受光周期影响较小。低温锻炼期短日照处理对淀粉积累诱导作用显著高于长日照。低温锻炼期温度对笃斯越橘抗冻性起主要作用;短光周期可提高低温锻炼效果,主要与脂肪酸不饱和度提高及淀粉含量增加有关。研究揭示笃斯越橘抗冻性形成的生理生态机制,为越橘属植物抗寒栽培、种质筛选和新品种培育提供理论依据。

Effect of photoperiod on contents of fatty acids and carbohydrate in shoot of Vaccinium uligiuosum L.during cold acclimation

Effect of photoperiod treatments on the fatty acid contents and carbohydrate contents in shoot of Vaccinium uligiuosum L.during cold acclimation was studied by GC/MS and HPLC,aimed to explore the relationship between freezing resistance and fatty acids or carbohydrate and elucidate the physiological and ecological mechanism of freezing resistance formation.The three-year-old seedlings of Vaccinium uligiuosum L.were selected as the testing materials.The seedlings were exposed to short day (10 h),4℃ and long day (14 h),4℃ under controlled conditions for 21 d,respectively.The changes of relative conductivity,fatty acid content,soluble sugar content and starch content in shoot after treatments were recorded.The results showed that the saturated fatty acid content was reduced,the proportion of unsaturated fatty acids and fatty acid unsaturation were significantly increased by interaction of low temperature and short day.Stearic acid content and fatty acid unsaturation were associated with the freezing resistance.The contents of sucrose,glucose,fructose and the total soluble sugar were increased during cold acclimation,which mainly related to the low temperature,not to photoperiod.The accumulation of starch induced by short day treatment was significantly higher than that induced by long day treatment during cold acclimation.The results indicated that low temperature played a major role for the formation of freezing resistance in shoot of Vaccinium uligiuosum L.during cold acclimation;short photoperiod improved the effect of cold acclimation,which was related to the increasing of the fatty acid unsaturation and the starch content.The results preliminarily revealed the physiological and ecological mechanism of the freezing resistance formation,which provided the theoretical evidence to some extents for the cultivation of cold resistance,screening of germplasm and the breeding of new variety in Vaccinium.