干旱胁迫条件下臭柏的生长

GROWTH OF SABINA VULGARIS ANT. UNDER DROUGHT STRESS

为了探讨干旱胁迫条件下臭柏(SabinavulgarisAnt.)的生长特性及适应机理,进行了长期的野外调查和室内模拟实验。野外调查是在毛乌素沙地的天然臭柏分布区,设置固定样方,定期测定样方内立地条件不同的24个臭柏群落。室内实验是将臭柏插穗带往日本冈山大学扦插,生根扦插苗移植于砾耕栽培装置中,设置对照区,弱干旱胁迫区,强干旱胁迫区(培养液渗透势分别为0MPa,-0.1MPa和-0.3MPa)3种处理进行长期的干旱胁迫室内模拟实验,研究各处理区臭柏的生长变化规律。结果表明:(1)毛乌素沙地的天然臭柏群落的半径以每年约11cm的速度逐渐扩大,随着干旱胁迫的加剧,群落的半径生长量及最大树高都减少;(2)室内干旱胁迫条件下,臭柏的伸长生长和地径生长逐渐减少,而且伸长生长优先受到抑制。

Sabina vulgaris is an evergreen coniferous shrub, and expands its area of patches by growth of stolon along the ground surface in Maowusu Sandy Land of China. It is an important tree for preventing desertification too. To discuss growth characteristics and adaptive mechanisms of Sabina vulgaris under drought stress,the growth characteristics of Sabina vulgaris were measured,by combining investigation in field and experiment in laboratory. Field investigation of 24 patches of Sabina vulgaris at Mowusu Sandy Land in different sites in China was done. Three treatments of control,light drought stress,strong drought stress in gravel culture system at Okayama University in Japan were set up in laboratory , the osmotic potential of the culture solution was maintained at 0 MPa,-0.1 MPa,-0.3 MPa. for all the experimental period by polyethylene glycol (PEG, molecular weight 6000).The results showed that(1)patches of Sabina vulgaris in Mowusu Sandy Land are expanding every year at 11 cm radial growth,where drought stress is strong,radial growth and maximum tree height are reduced;(2) Elongation growth and basal growth are decreased gradually,and first elongation growth is restrained under drought stress in laboratory.