ISHS Acta Horticulturae 773: XXVII International Horticultural Congress - IHC2006: International Symposium on Citrus and Other Tropical and Subtropical Fruit Crops
A STUDY ON SOME PHYSIOLOGICAL AND ANATOMICAL ASPECTS OF ROOTING 'NABALI' AND 'RASEEI' OLIVE SEMI-HARDWOOD STEM CUTTINGS |
| Authors: | S.J. Ayoub, M.M. Qrunfleh |
| Keywords: | abscisic acid, adventitious roots, cytokinin, gibberellin, indole-3-acetic acid, sclerenchyma ring |
| Abstract:
The physiology and anatomy of adventitious root (AR) formation in ‘Nabali’ and ‘Raseei’ olive semi-hardwood stem cuttings were investigated. This included changes in rooting promoters and inhibitors, and changes in plant hormones in buds and leaves; and the sequence of AR formation in both cultivars. The results indicated that ‘Raseei’ cuttings had significantly higher rooting percentage, higher average number of roots per cutting, and lower callus formation percentage than ‘Nabali’ cuttings in all sampling dates. These differences are believed to be related, firstly, to promoters and inhibitors of rooting as buds and leaves of both olive cultivars contained 3 fractions, which showed variations in content throughout the sampling dates. For instance, ‘Raseei’ leaves and buds contained only promoters of rooting while ‘Nabali’ leaves and buds contained both promoters and inhibitor of rooting. Secondly, buds and leaves of both olive cultivars showed variation in IAA, ABA, GAs and cytokinin contents. Thirdly, the cross sections of ‘Nabali’ and ‘Raseei’ cuttings were basically the same where root initials origin is the cambial zone. In both olive cultivars, sclerenchyma tissue did not act as a mechanical barrier for AR formation. However, a noticeable increase in cortex thickness was observed only in ‘Nabali’ during rooting of cuttings, which might act also as a barrier of root primordial development. Formation of root initials was found to occur in ‘Raseei’ and ‘Nabali’ cuttings, 2 and 4 weeks from planting time, respectively, indicating faster rooting ability in ‘Raseei’. Rooting of ‘Nabali’ cuttings was preceded by callus formation, which was not observed in ‘Raseei’. Based on the results obtained, ‘Nabali’ can be described as being difficult-to-root, and ‘Raseei’ is easy-to-root olive varieties. | |
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