内源激素IAA和ABA含量与黑杨苗期高生长关系

Correlation between Endogenous IAA, ABA Contents and Height Growth of Black Poplar at the Seedling Stage

以黑杨派3个无性系为材料对其生长进行定位观测,用石蜡组织切片技术研究伸长节间和成熟节间的结构区别,并用GC-MS-SIM法测定幼叶等有代表性组织的内源IAA和ABA含量。结果表明:1)节间数月增量与苗高月增量间呈显著正相关,第1和第2节间总长与苗高月增量、IAA含量、ABA含量及IAA/ABA无显著相关;2)伸长节间细胞较小,排列紧密,次生木质部不明显;成熟节间细胞较大,排列松散,有明显的次生木质部;3)5—7月,凌丰1号3个幼嫩组织部位的内源IAA含量、ABA含量、IAA/ABA、节间数月增量和苗高月增量都在增大;7月,3个无性系的节间数月增量和苗高月增量的排列顺序与幼嫩组织的IAA含量没有相关性,与幼叶的ABA含量呈显著负相关,与顶芽的IAA/ABA呈显著正相关。不能用幼叶等组织的内源IAA含量来预测多个无性系苗高顺序,幼叶的ABA含量可作为预测多个无性系苗高顺序的参考指标,建议用顶芽的IAA/ABA对杨树苗高进行早期预测。

The contents of endogenous IAA and ABA in different tissues at the seedling stage of three black poplar clones were determined by GC-MS to investigate correlation between the height growth of poplar and the endogenous hormones,and to identify influence factors of early selection in poplar seedling height.At the same time,height growth of the seedling was measured,and tissue structure of the elongating internode and mature internode were discriminated by paraffin section.The results showed that：1） Increase in monthly internode numbers was significantly positively correlated with the monthly seedling height increment.There were no significant correlation between the total length of the first internode and the second internode and seedling monthly increasing height,IAA content,ABA content,the ratio of IAA to ABA.2） The cells of elongating internode were small and arranged compactly,and the secondary xylem was not distinct.The cells of mature internode were bigger and arranged loosely,and the secondary xylem was distinct.3） the monthly increasing internode numbers,monthly increasing seedling height,IAA content,ABA content and the ratio of IAA to ABA of three young tissues of the clone ‘ Lingfeng1 ＇ increased from May to July.In July,sequence of monthly increasing internode number and monthly increasing seedling height were not correlated with endogenous IAA content,and were significantly negatively correlated with endogenous ABA contents of young leaves,and were significantly positively correlated with the ratio of IAA to ABA of apical buds.Endogenous IAA content of young leaves and other organs could not be used as the index to predict sequence of seedling height of clones.But Endogenous ABA content of young leaves was able to be used as the reference index.Early prediction of seedling height in poplar can be conducted by using the ratio of IAA to ABA of apical buds.This study lays the groundwork for early selection of prior clones in seedling height and the basis of genetic engineering breeding for IAA and ABA.