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以塔里木河下游的胡杨为对象,研究胡杨母株与其克隆幼株间的克隆水分整合特征及对克隆幼株生理机能的影响.结果表明:胡杨母株与其克隆幼株间存在明显的以顶向传输为特征的水分整合,母株对克隆幼株的日平均水分整合流量为同区域长势相近的实生幼株通过自身根系日平均获取水量的3倍,克隆幼株因水分整合而能够获取与母株相似且较实生幼株水分来源相对较深层的土壤水,拥有更好的水分获取能力.这使胡杨克隆幼株较实生幼株保持显著更高的叶片水分含量,且黎明前和正午叶水势分别显著增加10.0%和29.7%.更好的水分生理状态使克隆幼株的光合电子传递速率与光适应下实际光化学效率显著高出实生幼株23.4%和11.5%,并能够保持显著更低的光系统Ⅱ过剩激能比例和光抑制风险.这可能让胡杨克隆幼株在极端干旱生境中较实生幼株保持更高的生存优势.
The Populus euphratica in the lower reaches of the Tarim River was used to study the clonal-water integration characteristics of Populus euphratica and its cloned young plants and the effect on the physiological function of the cloned young plants.The results showed that there was obvious top transmission between the Populus euphratica and its cloned young plants , The integrated daily average water flow rate of the young plants to the cloned young plants was three times of the average daily water intake of the young seedlings of the same growing region through their own roots. The relatively deeper water source soil water had better water harvesting ability, which made the young clone of Populus euphratica maintain a significantly higher leaf water content than that of the young plant, and the water potential before and mid-day significantly increased by 10.0% and 29.7% respectively. Better hydropathic conditions made the photosynthetic electron transfer rate and the actual photochemical efficiency under light adaptation of clonal young plants significantly higher than that of the young seedlings by 23.4% and 11.5%, respectively, and maintained a significantly lower excess energy ratio and photoinhibition risk of photosystem Ⅱ. This may allow Populus euphratica clonal young plants to maintain a higher survival advantage than the live seedlings in extremely arid habitats.