Changes of Endogenous Hormones in Macadamia during Flower Bud Differentiation

[Objective] The study was to research the effect of endogenous hormones in Macadamia on its flower bud differentiation.[Method] With 5 years old Macadamia varieties of Own Choice(O.C.) and Beaumont(695) as the tested materials,their phenophases of the flower bud differentiation were observed and their contents of endogenous hormones in fine root,branch and leaf were detected during their flower bud differentiation.[Result] The appearance time of flower bud,the inflorescance elongation time and full-bloom stage of O.C.were all earlier than that of 695.In the middle ten days of October,the contents of GA3 in leaf and branch of O.C.were lower(213.78,250.00 ng/g),but those in 695 were higher.The contents of ABA and ZT in leaf and branch of O.C.reached the peak(132,48,178,111 ng/g)in the middle ten days of October,but the ABA content in leaf and ZT content in branch of 695 were lower from September to the middle ten days of October.The value of ABA/GA3,ABA/IAA,ZT/GA3,ZT/IAA in each organ of O.C.were all higher than that of 695.[Conclusion] The Macadamia with low level of GA3 and high level of ABA,ZT,ABA/GA3,ABA/IAA,ZT/GA3 and ZT/IAA in fine root,branch and leaf were beneficial to its flower bud differentiation.