水分、氮肥及MeJA处理对白桦三萜积累特性的影响

Effects of Water,Nitrogen and Methyl Jasmonate Treatment on Triterpenes Accumulation in Birch(Betula platyphylla Suk.)

以一年半生白桦幼树为试材,研究水分、氮肥和茉莉酸甲酯(MeJA)处理对白桦三萜物质积累的影响,并对白桦植株中三萜积累规律进行了探讨。结果表明:(1)白桦幼树植株中总三萜主要分布在茎皮和叶片,根皮中最低,平均含量分别为71.94、81.60和25.45mg.g-1;叶片中总三萜积累高峰出现在6、7月份,茎皮和根皮中总三萜积累高峰分别出现在8月份和7月份。(2)干旱胁迫早期(6月)中度和重度干旱胁迫显著促进了叶中总三萜积累,分别是对照的1.24和1.27倍。茎皮中,除7月水分胁迫处理显著高于对照外,其它各月份水分胁迫不利于茎皮中总三萜含量积累,干旱胁迫不利根皮中三萜积累。(3)施氮早期(6月)不利于三萜在叶片和根皮中积累,中后期(7～10月),氮肥处理对三萜积累有显著促进作用;而施氮早期(6～7月)促进茎皮中三萜积累作用。(4)MeJA喷施处理对叶片和根皮中三萜积累(7月～10月)均具有显著的促进作用,在积累高峰期分别是对照的1.42倍和1.52倍。(5)轻度干旱、氮肥均促进了白桦幼树株高的增长和生物量的积累,而MeJA处理对整株生物量的积累不利。

With one year and a half birch saplings as experimental materials, we lnvestlgateo tne eilects oi water,nitrogen and methyl jasmonate（MeJA） treatment on the accumulation of triterpenes and the accu- mulated regulation of triterpenes in birch. The results showed that, total triterpene is mainly distributed in stem bark and leaf in birch sapling,the average content is 71.94 mg· g-1 and 81.60 mg · g-1 respectively, and the lowest in root bark,which is 25.45 mg · g-1. The accumulated peak of total triterpene in leaf is June and July;But accumulated peaks of total triterpene in stem bark and root bark are August and July, respectively. Moderate and severe drought stress had significantly contributed to the accumulation of total triterpene in leaf in the early stage of drought stress,which are 1.24 and 1.27 times of the control. The ac- cumulation of total triterpene for water stress in stem bark is significantly higher than at of control in July.Water stress has not conducived to total triterpene accumulation of the stem bark in other months. In addi- tion, drought stress is adverse to triterpene accumulation in the root bark. Nitrogen treatment in early stage （June） is not conducive to triterpenoids accumulation in the leaves and root bark,but has remarkably con- tributed to the triterpenoids accumulation in late stage （July-October）. However, the nitrogen treatment has contributed to the triterpenoids accumulation in the stem bark in early stage （June-July）. MeJA spra- ying has promoted the triterpenes accumulation in the leaf and root bark. In the accumulating peak stage, with 1.52 and 1.42 times of the control. Light drought,nitrogen fertilizer both contribute to height growth and biomass accumulation of birch saplings, but MeJA treatment is disadvantage on the whole plant bio- mass accumulation.