低温胁迫对李属4种砧木几个抗寒指标的影响

以李属天山樱桃、毛樱桃、榆叶梅和野生樱桃李的休眠枝条为试材,采用人工冷冻降温的方法,设置温度梯度分别为-18,-21,-24,-27,-30,-33,-36,-39,-42℃,以-15℃为对照(CK),测定不同低温胁迫下休眠枝条的电解质渗出率、萌芽率、脯氨酸含量和丙二醛含量,利用Logistic方程对电解质渗出率变化曲线进行拟合,计算半致死温度,并用主成分分析法对4项指标进行分析。结果表明,低温胁迫下4种果树休眠枝条的电解质渗出率都随温度下降而上升,半致死温度为-25.3～-40.1℃,恢复生长法与半致死温度的结果基本一致,游离脯氨酸含量和抗寒性相关性明显,而丙二醛含量不十分吻合。4种李属砧木抗寒性大小依次为天山樱桃>榆叶梅>毛樱桃>野生樱桃李。

Effects of Low Temperature Stress on Some Cold Resistance Indexes of Four Kinds of Root Stock Prunus

In this paper,the dormant branches of Cerasus tianschanica,Cerasus tomentosa,Prunus triloba and Prunus divaricata were used as test materials,the penertrating rate of electrolyte,the germination rate,the proline content and the MDA content four cold resistance indexes under different low-temperatures treatment CK（-15 ℃）,-18 ℃,-21 ℃,-24 ℃,-27 ℃,-30 ℃,-33 ℃,-36 ℃,-39 ℃ and-42 ℃ were determined by using artificial freezing temperature.The semi-lethal temperature（LT₅0）was obtained on the basis of conductivity and Logistic equation and the indexes of four cold resistances were analysised by pricinpal component.The results showed that the penertrating rate of electrolyte were increased with temperature decreased,the semi-lethal temperature ranged from-25.3 ℃ to-40.1 ℃,this corresponded well with LT₅0 result.The free Pro content changed significantly with the cold resistance but the MDA content had no relationship with the cold resistance.The abilities of cold resistance was listed as Cerasus tianschanica> Prunus triloba> Cerasus tomentosa> Prunus divaricata.