渗透胁迫和pH对中间锦鸡儿种子萌发和幼苗生长的影响

Response of Osmotic Stress and pH on Caragana intermedia Seed Germination and Seedling Growth

以中间锦鸡儿种子为试材,采用中心组合试验设计和响应曲面分析方法,在实验室条件下,探讨了渗透势(-1.76~0.00MPa)和pH(5.0~8.5)对中间锦鸡儿发芽指数(Gi)、活力指数(VI)、发芽率(GR)、相对发芽率(relative GR)、胚轴长(H)、胚根长(R)、茎粗(SD)的协同影响。结果表明:不同渗透势下,渗透胁迫越大,Gi、GR、relative GR越低。当渗透势为-0.88的情况下,pH过高(pH 8.5)和过低(pH 5.0)时均低于pH在6.8时的GR、relative GR。A^2(Ψπ~2)对SD的影响接近(P=0.050 4)显著水平;pH对5个指标的影响达到极显著或显著水平,即B-pH和B2(pH2)分别对Gi、VI有极显著(P=0.009 5,P=0.001 2)和显著(P=0.034 9,P=0.034 6)影响,B2分别对GR、relative GR有显著(P=0.048 7)影响,B-pH对R有显著(P=0.035 2)影响。相同pH处理下,渗透势越高茎粗值越大。基本上渗透势越靠近中心点SD越小,越往两边SD值越大。pH 6.9~8.5时,随着pH的增大,VI、GR、relative GR、H均呈逐渐变小的趋势。pH 6.0~8.5时,R随着pH的增大而降低;渗透势和pH分别为-0.26MPa和5.9时,各生长指标达到最优值,Ψπ、pH、H、R、SD、GR、relative GR、Gi、VI分别为-0.26 MPa、5.9、11.78 mm、7.45 mm、1.70mm、73.75%、92.19%、35.85、4.99,可靠性为0.75。可见微量的渗透胁迫和微偏酸的环境有助于中间锦鸡儿种子的发芽和幼苗的生长。

Taking C.Intermediaseed as test materials,by adopting central composite design and response surface analysis method,the synergetic effects of osmotic potential（-1.76-0.00MPa）and pH（5.0-8.5）on Gi,VI,GR,relative GR,H,R,SD of C.intermediaunder laboratory conditions were discussed.The results showed that the Gi,GR and relative GR decreased with increasing osmotic stress at differentΨπ.Too high（pH 8.5）and too low（pH 5.0）of pH,GR,relative GR were lower than these of pH 6.8,when the osmotic potential at-0.88 MPa.A^2（Ψπ~2）closed to significant（P=0.050 4）impact on SD;pH achieved extremely significant and significant effects on 5index,B-pH and B^2（pH^2）had extremely significant（P=0.009 5,P=0.001 2）and significant（P=0.034 9,P=0.034 6）impact on Gi and VI,respectively,B^2 had significant（P=0.034 9,P=0.048 7）impact on GR and relative GR,respectively,B-pH（P=0.035 2）had a significant（P=0.035 2）impact on R.SD increased with increasing osmotic stress in the same pH treatment.A smaller SD value when the osmotic potential closed to the center point,the value increased when the osmotic potential closed to edge,basically.When the pH 6.9~8.5,Gi,VI,GR,relative GR,H showed a tendency of gradually decreased with increasing pH value.When the pH 6.0~8.5,R decreased with increasing pH value;Osmotic potential and pH at（-0.26,5.9）,growth index reached the optimal value,Ψπ,pH,H,R,SD,GR,relative GR,Gi and VI,reached to-0.26 MPa,5.9,11.78 mm,7.45 mm,1.70 mm,73.75%,92.19%,35.85 and 4.99,respectively,the desirability were0.75.So osmotic stress of trace amounts and micro-acidic environment promote the seed germination and seedling growth of Caragana intermedia.