低温胁迫对3种柱花草幼苗抗性生理指标的影响

PHYSIOLOGICAL INDEXES EFFECT OF 3 KINDS OF STYLOSANTHES BY COLD STRESS

通过测定柱花草叶片质膜相对透性、可溶性糖含量和叶绿素含量等生理指标,研究3个柱花草品种即热研二号柱花草(Stylosanthes guianensis cv ReyanⅡ)、热研五号柱花草(Stylosanthes guianensis cv.ReyanⅤ)、西卡柱花草(Stylosanthes scabra Vog)在自然条件下和人控低温条件下这些生理指标连续7d的变化规律,比较这3个柱花草品种抗寒能力的差异。结果表明,在5℃时胁迫第7d,热研5号柱花草叶绿素a含量从2.31下降至1.17,下降率为49.78%,下降幅度最小;质膜透性从0.237上升至0.590,变幅为148.94%,上升幅度最小;可溶性糖含量从12.127上升至28.980,变幅为205.71%,上升幅度最大,可溶性糖积累最多。3种牧草中,热研5号柱花草的抗寒性较强,热研2号柱花草次之,西卡柱花草对低温的适应性较差。

Measured physiological indexes of plasma permeability, the content of soluble sugar, the content ofchlorophyll, 3 kinds of Stylosanthes spp. Cultivars （Stylosanthes guianensis cv.ReyanⅡ, Stylosanthes guianensiscv.Reyan Ⅵ, Stylonsanthes scabra Vog.）,we found that leaves under controlled cold conditionand and naturalconditions the Change law of these physiological indexes in seven days compare among the three physiologicalprocess species the cold tolerance. The results shows that：Under 5℃ for 7 days, the content of chlorophyll ofStylosanthes guianensis cv.Reyan Ⅵ declined from 2.13% to 1.17%,the significantly is 49.78%, the declinedsignificantly is minimal; The increasing of plasma permeability from 0.237% to 0.590%, the significantly is148.94%, the increasing significantly is minimal; The increasing of the content of soluble sugar from 12.127%to 28.980%, the significantly is 205.71%, the increasing significantly is maximal; Soluble sugar content of wasdramatically increased. So the Stylosanthes guianensis cv.Reyan Ⅵ was suited to low-temperature and had high？er ability of resisting cold, the order of chilling resistance for those kinds grasses was Stylosanthes guianensis cv.ReyanⅡ, Stylonsanthes scabra Vog.