The abstract of

Effect of Different Factors on Rooting Ability and Shooting in Olive (Olea europaea L., cv. Dgel) Cuttings

By Banaz Abdullah Hussein

September/2016

 

The present study was carried out between 2014 and 2015in the Central Plant Nursery of Ainkawa, Erbil. The current study consisted of five greenhouse experiments using hardwood stem cuttings of olive; Dgel cultivar growing at Ainkawa ornamental nursery. The experiments included the study of the effects of different factors related to rooting ability. The first experiment was composed of the effect of IBA at concentrations of (0, 2000, 3000, 4000 and 5000 mg.l-1) on rooting ability. The second experiment included using of cuttings from the different parts of the shoot, including intermediate, basal, apical and lateral positions, to evaluate their effects on rooting capacity. The third experiment was involved the effect of different collection dates on rooting ability and the fourth experiment consisted of the effect of some different rooting media; coarse river sand, garden soil, perlite and peatmoss on rooting ability. While in the fifth experiment, the effects of IBA at 0 and 4000 mg.l-1 were examined on biochemical changes occurring in cutting bases during root formation, as well as on anatomical features to find out their interactions to rooting ability.

Data were analyzed statistically by Statistical Package for Social Sciences using C.R.D. design for greenhouse experiments with five replicates and factorial experiment in C.R.D. design with three replicates for chemical analysis. When ANOVA showed a significant (P < 0.05 or 0.01) effect, Duncan’s Multiple Range Test where used to compare mean treatments. The results could be recapitulated as follows:

1- Cuttings treated with different concentrations of IBA (0, 2000, 3000, 4000 and 5000 mg.l-1) by quick dip method showed significant differences in rooting characteristics. The maximum rooting percentage (68.00%) was obtained with 3000 mg.l-1, while the largest roots number (14.40); the longest root length (10.12 cm); the highest root fresh and dry weight (0.241 g,0.097g) respectively were achieved at 4000 m g.l-1. Significant increases in shooting percentage and shoot characteristics were observed with IBA concentrations as compared to control. The highest rate of branches number, shoot length, fresh and dry weight (3.200, 4.940 cm, 0.278 g and 0.114 g) respectively were recorded at 4000 mg.l– 1 IBA.

2- The cuttings developed from lateral branches had greater rooting and shoot characteristics and the basal portion of the shoot was better than intermediate section within the same shoot.

3- Cutting’s collection date showed significant differences on rooting and shooting properties. The highest values were registered on April 15, whereas, the failure cuttings growth or the minimum values for root-shoot characteristics were noted during November and December months.

4- Compared to others, sand media demonstrated better results than others in all criteria, followed by peat moss, garden soil and perlite except for the shoot length (6.580 cm), where peat moss was found better (7.040 cm). In sand medium the highest values of rooting percentage, root number/cutting, root length, fresh weight and dry weight of roots were (46.00%, 13.20, 7.420 cm, 0.304 g 0.131g) respectively, as well as the highest shooting percentage, branches number, leaves number, fresh vegetative weight and dry vegetative weight were (56.00%, 3.400, 14.80, 0.404 g, and0.183g) respectively, were noted with sand.

5- IBA caused significant increase in total soluble sugars, total nitrogen and total phenolic compounds content in the bases of cuttings during root formation. At the same time the starch, C/N ratio and total carbohydrates decreased significantly.

6- Anatomical structure of olive cuttings were similar to that of the woody dicotyledon stems, where continuous sclerenchyma ring surrounding the primary phloem layer. Adventitious roots arised inside sclerenchyma layer which were observed between the phloem and cortex, and they grew through tissues located outside the point of origin. This sclerenchyma ring did not constitute a barrier to emergence of adventitious roots. During the rooting period, the continuous sclerenchyma ring was broken into disunited pieces or partially disappeared from some locations especially in IBA-treated cuttings.