不同干旱环境对赤松、樟子松、彰武松生理的影响

Effects of Extreme Drought Environment on Physiology of Pinus densiflora,Pinus sylvestris var. mongolica and Pinus densiflora var. zhanguensis

选择赤松、樟子松、彰武松3年生苗木为试验材料,研究植物体在极端干旱环境内生理生化的变化。结果表明:(1)正常状态下叶比导率(LSC)表现为彰武松>赤松>樟子松;木质部导水率损失百分数(PLC)为赤松>彰武松>樟子松;边材导水率为赤松>樟子松>彰武松,叶片水势日间平均樟子松最高,赤松清晨水势最低,丙二醛含量彰武松最高,3树种性状各有高低。(2)随着干旱胁迫强度的增加,3树种叶片水势和枝条导水性均呈下降趋势;木材栓塞程度和丙二醛含量呈增加趋势,3树种的PLC均值在轻度胁迫时达到20%,中度胁迫时达到32%!40%,重度胁迫时达到52%!65%,重度干旱胁迫已经对枝条的脆弱性产生了影响,但仍然较自然干旱下的重度胁迫所造成的导水率损失(80%)要小,PLC增加顺序为樟子松>彰武松>赤松;丙二醛含量在轻度干旱中变化并不明显,但中度和重度时有明显增加,增至20~25 mmol·g-1,增幅顺序为彰武松>赤松>樟子松。

Taking 3-year-old Pinus densiflora,Pinus sylvestris var. mongolica and Pinus densiflora var. zhanguensis as the research materials,the physiological and biochemical changes of plant in extremely arid environments were studied. Result shows that：（1） Under normal conditions,leaf special conductance（LSC） Pinus densiflora var. zhanguensis 〉 Pinus densiflora 〉 Pinus sylvestris var. mongolica;in terms of percentage loss of xylem hydraulic conductivity（PLC）,Pinus densiflora〉 Pinus densiflora var. zhanguensis 〉Pinus sylvestris var. mongolica;in terms of sapwood-specific hydraulic conductivities,Pinus densiflora 〉 Pinus sylvestris var. mongolica Pinus densiflora var. zhanguensis. The water potential of the leaves of Pinus sylvestris var. mongolica is the highest during the day. The lowest water potential of Pinus densiflora is in the early morning. Concentration of malondialdehyde in Pinus densiflora var. zhanguensis is the highest,traits of three kinds of pine have their own high and low.（2） With the increase of drought stress intensity,the water potential and the hydraulic conductivity of the three kinds of pine leaves showed a decreasing trend： The degree of embolism and the content of MDA increased. At the time of mild stress,the mean value of PLC is 20%,and 32-40% in moderate stress,52-65% in severe stress,it could achieve 80% in severe stress under natural drought,and the increased order of PLC is P. sylvestris var. mongolica P. densiflora var. zhanguensis 〉 P. densiflora. The content increase of MDA in the mild drought is not obvious,but in the moderate and severe drought conditions it increase 20-25 mmol·g^-1,the increased order is P. densiflora var. zhanguensis 〉P. densiflora 〉 P. sylvestris var. mongolica.