不同铵硝配比营养液对生菜内源激素的影响

采用水培试验探讨了不同铵氮和硝氮配比(简称铵硝配比)对不同品种生菜(Lactuca sativa L.)内源激素的影响.结果表明,不同铵硝配比对生菜根系和叶片中的内源激素含量有显著影响.随着营养液中NH4+-N比例的增加,生菜根系和叶片的生长素(IAA)含量及异戊烯腺嘌呤(iPAs)含量均随着增加,并在营养液中NH4+-N比例为25％时达最高.然后,随着NH4+-N比例进一步增加到50％,生菜根系和叶片的IAA含量及iPAs含量反而下降.生菜根系和叶片的脱落酸(ABA)含量随着营养液中NH4+-N比例的增加而下降,并在营养液中NH4+-N比例为25％时达最低.然后,随着NH4+-N比例进一步增加到50％,生菜根系和叶片的ABA含量反而增加.随着试验进程从4叶期推进到6叶期、8叶期,供试生菜根系和叶片中的内源激素水平随之下降.

Effects of NH4+-N to NO3-—N Ratios on Endogenous Hormones of Lettuce Cultivars

The effects of different NH4+-N to NO3-—N ratio on content of endogenous hormones of lettuce(Lactuca sativa) were studied by solution.The results showed that the effects of different NH4+-N to NO3-—N ratio on endogenous hormones in roots and leaves of lettuce were significant.The content of IAA and iPAs in roots and shoots increased with the increasing of NH4+-N to NO3-—N ratio,and the contents reached the highest when the NH4+-N to NO3-—N ratio was 25∶75.However,the content decreased with further increase of the NH4+-N to NO3-—N ratio from 25∶75 to 50∶50.The change trend of ABA content was just opposite to that of IAA and iPAs content.With the growth of lettuce from 4-leaves to 6-leaves and 8-leaves,the content of endogenous hormones decreased in roots and shoots.