柴胡幼苗越冬抗寒性及其相关生理指标筛选

以北柴胡、地产柴胡、三岛柴胡的根为试验材料,以早春植株成活率为越冬抗寒性指标,测定越冬期不同柴胡品种根系生理生化特征,进行柴胡抗寒性综合评价,并对主要抗寒生理指标进行通径分析和相关性分析,以探讨冬季自然低温条件下柴胡生理特性与抗寒性的关系,筛选适合柴胡越冬抗寒性鉴定的生理指标。结果表明:(1)北柴胡、地产柴胡、三岛柴胡返青期的返青率依次为80%、50%、10%,且各品种间差异显著。(2)3个品种柴胡越冬期根系可溶性糖含量、游离脯氨酸含量、可溶性蛋白含量、根系活力与返青率大小顺序一致,其中北柴胡根系游离脯氨酸平均含量分别为地产柴胡和三岛柴胡的2.44倍和4.49倍,且可溶性蛋白含量显著高于地产柴胡、三岛柴胡,但3个品种柴胡的相对电导率、丙二醛含量水平与返青率大小顺序相反。(3)自然越冬过程中,各柴胡品种的根系活力均呈下降趋势,且以三岛柴胡根系活力下降幅度最大,达80%,而北柴胡根系活力下降幅度最小为52.04%。(4)越冬期3个柴胡品种的越冬抗寒性综合排序为:北柴胡地产柴胡三岛柴胡;柴胡根中脯氨酸含量、可溶性蛋白含量与综合评价值呈极显著正相关关系,相对电导率与综合评价值呈显著负相关关系;生理指标决策系数的大小顺序依次为脯氨酸含量可溶性蛋白含量电导率。研究表明,越冬期柴胡根系游离脯氨酸含量是影响其抗寒性的主要影响因素,其含量可作为评价柴胡抗寒性的指标。

Cold Resistance and Related Physiological Indexes Identification of Bupleurum Seedlings during Wintering Stage

This experiment takes Bupleurum chinense DC.,Bupleurum chinense DC.(lushi) from Lushi of Henan Province and Bupleurum falcatum L.roots as the materials.In early spring,with the survival rate of plants as winter hardiness indexes,the physiological and biochemical indexes of different varieties of Bupleurum root were detected during winter period.Path analysis and phase analysis were used to evaluate Bupleurum cold resistance and cold resistance physiological indicators.The purpose is to explore the relationship between dynamic changes and cold resistance physiological indexes of Bupleurum in natural low temperature conditions and to filter out the most suitable physiological indicators that identify Bupleurum winter hardiness.The results as follows:(1)The overwinter survival rate in turn was 80%(B.chinense DC.),50%[B.chinense DC.(lushi)],10%(B.falcatum L.),and there were differences between different cultivars.(2)The change of soluble sugar content,proline content,soluble protein content and root activity were consistent with that of the overwinter survival rate,but the relative electrolytes and MDA content of the 3 cultivars were in an opposite order.Among them,the free proline content of B.chinense DC.was 2.44 fold of B.chinense DC(lushi).and 4.49 fold of B.falcatum L..The soluble protein content of B.chinense DC.was much higher than that of others.(3)During natural overwintering,the root activities of all cultivars showed a decreasing trend.The decrease margin of B.falcatum L.was the largest(80%),the decrease margin of B.chinense DC.was the smallest(52.04%).(4)The winter hardiness of three Bupleurum species of comprehensive order was:B.chinense DC.>B.chinense DC.lushi>B.falcatum L.,the comprehensive appraisal was significantly positively correlated with the contents of protein and proline,but it had significant negative correlation with the relative electrolytes.The decision coefficient of physiological indexes in size order was proline content>soluble protein content>conductivity.The results showed that:the free proline content of roots was the main factor which influenced cold resistance during natural overwintering,which could be used as evaluation index of cold resistance of Bupleurum.