不同品种杜鹃花朵自动脱落相关酶活性比较

Comparative study on related enzyme activities of blossom automatic abscission process in different varieties of azalea

【目的】探讨不同品种杜鹃花朵花冠离区相关脱落酶活性的变化规律,为杜鹃花期调控和新品种选育提供参考依据。【方法】观测春潮、红精灵、春之舞和神州奇等4个品种杜鹃花朵的自动脱落率,分析其与杜鹃开花过程中花冠离区多聚半乳糖醛酸酶(PG)、果胶甲酯酶(PME)和β-葡萄糖苷酶活性的关系。【结果】红精灵和春潮的花朵自动脱落率较高,分别为92.280%和88.030%。除神州奇花冠离区的PG活性呈先上升后下降变化趋势外,其余3个品种呈先下降后上升再下降的变化趋势;除春之舞花冠离区的PME活性呈先下降后上升再下降的变化趋势外,其余3个品种呈先上升后下降的变化趋势。盛花期时,红精灵的PG和PME活性较高,分别为0.993 mg/(g·h)和0.069 U/gFW。春潮和红精灵开花过程中,其β-葡萄糖苷酶活性呈上升趋势,春之舞和神州奇的β-葡萄糖苷酶活性呈下降趋势;在开花过程的各时期,红精灵的β-葡萄糖苷酶活性均显著高于其他品种(P<0.05,下同)。相关性分析结果表明,PG与PME呈极显著正相关(P<0.01),二者均与自动脱落率呈显著正相关;β-葡萄糖苷酶活性与自动脱落率及PG和PME活性相关不显著(P>0.05)。【结论】PG和PME是促使杜鹃花朵脱落的关键酶,β-葡萄糖苷酶在杜鹃花朵脱落过程中也发挥积极作用。

【Objective】The variation patterns of related abscission enzyme activities in the abscission zone of corolla in different varieties of azalea were explored to provide reference for controlling the flowering period of azalea and breeding new varieties.【Method】The automatic abscission rates of four varieties(Chunchao,Hongjingling,Chunzhiwu and Shenzhouqi)of azalea were observed to analyze the relationships between them and polygalacturonase(PG),pectin methylesterase(PME)as well asβ-glucosidase activities in the abscission zone of corolla during flowering process of azalea.【Result】The automatic abscission rates of Hongjingling and Chunchao were relatively high,being 92.280%and 88.030%respectively.The PG activity in the abscission zone of corolla of Shenzhouqi increased firstly and then decreased,however the PG activities in other three varieties of azalea decreased firstly and then increased and decreased again finally.The PME activity in the abscission zone of corolla of Chunzhiwu decreased firstly and then increased and decreased again finally,however the PME activities in other three varieties of azalea increased firstly and then decreased.At full flowering stage,PG and PME activities of Hongjingling were high,which were 0.993 mg/(g·h)and 0.069 U/gFW respectively.During the flowering processes of Chunchao and Hongjingling,theirβ-glucosidase activities showed an increasing tendency,while theβ-glucosidase activities of Chunzhiwu and Shenzhouqi showed a decreasing tendency.Theβ-glucosidase activity of Hongjingling were always significantly higher than those of other varieties(P<0.05,the same below)in the different stages during flowering process.The result of correlation analysis showed that there was extremely significant positive correlation(P<0.01)between PG and PME,and both PG and PME had significant positive correlations with automatic abscission rate.Automatic abscission rate had no significant correlation withβ-glucosidase,PG and PME activities(P>0.05).【Conclusion】PG and PME are the key enzymes to impel blossom abscission of azalea,andβ-glucosidase also plays an active role in the blossom abscission process of azalea.