Abstract: The authors research the different rooting capacity of shoot cuttings of some cypress tree species, including Sabina vulgaris Ant., Platycladus orientalis(L.)Franco cr.'Sieboldii' ,P.orientalis(L.)Franco cv.'Semperaurescens' ,S.chinensis(L.) Ant., S.chinensis(L.) Ant. cv. 'Kaizuca',and Juniperus rigida Sieb. Et Zucc, and emphatically in quire into the physiological bases causing such different rooting capacity. According to the results, those cypress tree species can be divided into three types: easy rooting, more difficult and most difficult. The effects of NAA or IBA supplied in stimulating rooting of shoot cuttings are very complicated,as the differences are not only from tree species but also from different cuttings. Further the authors point out that these different effects are related to endogenous IAA/ABA ratio in cuttings. The higher IAA/IBA ratio may be the conditions for inducing adventitious roots. NAA application to cuttings can induce ETH production,whose level has correlations to NAA treatment and rooting capacity of tree species.

Key words: Shoot cutting, Growth regulator, Rooting capacity, Cypress tree species