Abstract:

One-year-old semi-hard branches and hard branches from mother trees of feijoa at different ages were used to study the relationships between rooting characteristics and anatomical structure of the cutting and their development process of adventitious roots by the method of paraffin section. The results showed that no marked difference in rooting ability of the cuttings from mother trees with different ages was found, but there was difference in anatomical structure between hard branches and semi-hard branches from the same age tree. The cuttings of semi-hard branches were easier to root than the hard branch cuttings, probably because the two materials had different rooting characteristics. The adventitious root of feijoa cuttings is derived from a type of induced root primordium, which originates from the junction of vascular cambium and pith rays. Most roots were produced in a range of 0.1-2 cm from the cutting end. Callus tissue could not produce root primordia. There were cyclical and sequential sclerenchyma cells in the phloem and no root primordium in the stems. These structure features may be one of main reasons that feijoa cuttings have low rooting rate.

Key words: Feijoa sellowiana, stem, cutting, adventitious roots, anatomy