稻株内源iPA和GAs变化与再生芽的关系

RELATIONSHIP OF ENDOGENOUS iPA AND GAs IN RICE PLANTS WITH THE GERMINATION AND GROWTH OF RATOONING BUDS

采用中国农业大学提供的植物激素ELISA方法,研究了杂交水稻中后期各器官中内源激素iPA和GAs的变化及其与再生芽萌发生长的相关性。结果表明,内源激素iPA,GAs变化与再生芽萌发生长关系密切;头季稻齐穗后5 d至19 d植株内源激素iPA,尤其是GAs的含量较低,而稻穗中内源激素含量水平相对较高,再生芽生长缓慢或处于休眠状态;齐穗19 d以后,随着稻穗中内源激素含量水平的降低,稻株叶、鞘和茎、芽中内源促进类激素iPA,GAs含量水平的增加,再生芽萌发、伸长的速度相应加快;齐稳后19 d下部节茎中iPA,GAs含量水平高于上部节茎,低位芽长于高位芽;齐穗后26 d,33 d上部节位茎、芽的内源iPA,GAs整体含量高于下部节位,上位芽生长速度快于下位芽。表明在一定条件下提高内源激素的整体含量,能打破再生芽的休眠,促进其萌发生长。

ELISA was made to monitor the variations in the contents of iPA and GAs in various organs during the mid and late growth stages of hybrid rice plants and to study their relationship with the germination and growth of the ratooning buds. In the 5-15 days after full heading, iPA and GAs were low in the vegetative organs of the plant and high in its spike and the rationing buds were dormant or grew very slowly. Starting from the 19th day after full heading, as the levels of endogenous hormones declined in the spike they increased in the leaf, stem and sheath, and the rationing buds sped up their germination and elongation. During this period, contents of iPA and GAs were higher in the buds at the lower nodes than at the higher nodes and, accordingly, the buds at lower nodes grew faster. Such results suggest that the enhancement of endogenous hormone level of the rice plants help the dormancy of the rationing buds and promote their growth.