الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
SUMMARY
The objectives of this work tend to reveal the following:
1- The growth behaviour of some ”Araceae” plants, i.e. Scindapsus aureus, Philodendron
scandens, P. bipinnatifidum; and P. erubescens.
2- Try to control or break the apical dominance to increase lateral branch formations in the
above mentioned four plant species.
3- Try to improve the vegetative propagation of Scindapsus aureus and Philodendron
scandens by using single node leafy soft stem cuttings.
To approach the aim of this study, series of experiments were carried out from 1988
till 1991 under the conditions of Plant Physiology Laboratory, Faculty of Agric.,
Moshtohor, as such tested plant species are used as indoor decorated plants. The study of
improving vegetative propagation included: (a), the best propagated medium; (b), the
proper time of the year during which the cuttings could be collected; (c), effect of node
position on the mother plant axes; (d), the role of some growth regulators and some growth
co-factors on the success of cuttings. In additions, chemical analysis of: some macro-and
micro-nutrients, carbohydrate fractions, amino acid fractions, chloroplast pigments, phenolic
compounds and some phytohormones, were carried out in an attempt to elucidate the
mechanism of rooting ability and the effects of some chemicals under investigations on
rooting process itself. During the course of vegetative propagation treatments, aquious
nutrient medium was initially used for root initiation and its development of such semihydrophytic
plants. In many experiments, the study was extended under pot culture
conditions (mixture of solid medium), to get some clue information about the long term
effects of the tested rooting factors, till the plants reached into marketable stage.
The obtained results may be summarized as follows:
1- Growth Behaviour:
1- It was suggested that the four tested species of A.raceae display
11Thigmonwrphogenesis” responses induced by many environmental factors, such as light
direction, gravity, and the contact of aerial foots and stems with the adjacent surface of any
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solid bodies. This II Thigmomorphogenesis” was more abvious in Scindapsus aureus and
Philodendron scandens.
2- All tested species exhibited complete and strong apical dominance.
3- Climber rootlets, ”aerial climber internoded rootlets” were grown in Scindapsus
aureus only, while such type of roots seemed to be absent completely in the tested three
species of Phelodendron.
4- All different tested four speciees emerged ”noded aerial functional roots” which
vary in their numbers according to the method of growing.
5- Complete discussion about the moorphological aspects were recorded usmg
modern technical termonology, as the growth behaviour and the type of leaves, nature of
axes development, and root formation, are not defined till now under cultivated conditions,
and that connected with their propagation methods. In other words, the growth pattern and
their shoot organization are completely varied according to environmental conditions, and
that may playa role in the apical dominance and their dormant state during a definite time of
the year.
6- The growth curves of different plant parts seemed to be more or less, sigmoid
shape, and the growth activity began slightly during February and increased continously till
it reached into the maximum during August and decline after that till it reached into nill
during January.
7- It was suggested that the four tested species were in dormant or rest state during
the coldest season, and their growth activity increased greatly during the warmest season, as
they are tropical plant.
11- Break of Apical Dominance and Stimulation of Lateral Branch Formations, in
Scindapsus aureus, Philodendron scandens, P.bipinnatifidum, and P. erubescens:
1) The removal of apical bud permits the formation of only one lateral branch, in the
four tested species.
2) GA3 at the rate of 4 ppm applied directly on axillary buds in the absence of apical
bud gave the best results to break apical dominance. as the highest lateral branch formations
were gained by such treatment, in Scindapsus aunus.
(225)
3) The presence of apical bud minimized the stimulatory effect of GA3 on the
oreakdown of apical dominance in Scindapsus aureus.
4) The new formed branches in GA3 treated plants possessed prophyll and cataphylls
leaves, as bladeless or reduced leaves were formed on such branches, in Scindapsus
aureus.
5) Foliar spray of GA3, BA both at the level of 100 ppm and PPJJJ at the rate of
5ppm seemed to have a slight effect on the break of apical dominance, as the resulted lateral
branch formations were very low and not developed into functional branches in the four
tested plant species. Thus, it was suggested that foliar application of the above mentioned
growth regulators at the forementioned rates seemed to have partial effect on apical
dominance.
6) It was suggested that the type of apical dominance in the four tested species is
from the strongest one, as only one lateral branch is formed after the removal of terminal
bud, and new formed branch established dominance over the remaining buds and cause them
to become inactive again.
III- Improving Vegetative Propagation of Scindapsus aureus and Philodendron
scandens.
ID-A) Preliminary studies:
1) The best medium used for the highest success of Scindapsus aureus and
Philodendron scandens cuttings was 1/4 Hewitt’s aquious nutrient solution.
2) The highest rooted cuttings percentage was gained by the cuttings collected from
June till August. However. it may be reccommended to collect the cutting during all of the
year except during December till February (the coldest sason).
3) The collecting cuttings during June till August stimulate early root initiation on
Scindapsus aureus and Philodendron scandens.
4) Node position on the axis seemed to have no significant effect on the rooting
ability of Scindllpsus aureus and Philodendron scandens cuttings.
(226)
5) Undesirable deformed roots were obtained by using relatively high rates ofIBA
md NAA, i.e from 5-20 ppm from both. Such deformed roots were more pronounced by
using NAA than lBA.
6) IBA, NAA stimulate the rooting ability of Scindapsus aureus and Philodendron
scan dens, however, IBA seemed to be superiour in this respect.
7) Rooting ability of Scindapsus aureus and Philodendron scandens cuttings
decreased with increasing the rate of IBA or NAA from 5 till 20 ppm. Accordingly, IBA
was used during the detail studies with very low rates, i.e. 0.1 or 0.2 ppm.
DI-B) Detail studies:
1) IBA, BA and their combinations affected the rooting ability of Scindapsus
aureus cuttings.
2) IBA at the very low rates, 0.1 or 0.2 ppm. Stimulate higher rooting ability of
Scindapsus aureus cutting. BA stimulated early root initiation and rooting ability of
Scindapsus au reus cuttings.
3) BA seemed to have a sinergistic effect of IBA in rooting ability and the number of
formed roots.
4) IBA and BA affected the number of root initiation in Scindapsus au reus cutting,
the best effect was gained by BA at the rate of 5 or 10 ppm, without any deformed effect on
roots, as there was no harrnoful effect on root shape by using any growth regulator under
the very low tested rates.
5) IBA, BA and their combinations regulated and controlled growth behaviour of
the developing cuttings during water culture phase (35 days from the begining of the
experiment) and also during pot culture phase which extended into 147 days after
retransplanting the plantlets.
6) The regulatory effect of rnA BA and their combination controlled the absorption
of many essential elements, and plant metabolism such as carbohydrate and amino acid
fractions in ScilldapSUS au reus.
(227)
7) rnA, BA and their combinations regulate the balance between different macroand
micro-nutrients in Scindapsus aureus tissues either during water culture phase or
during solid culture phase.
8) The controlling effect and regulating balance between the differnt nutrients and
the organic matters by using rnA and BA seemed to play an important role in the regulation
of rooting ability of Scindapsus aureus cuttings.
9) According to the abtained results from the previous experiment, another
experiment was carried out using IBA at the rate of 0.0 or 0.2 ppm, BA at the of 0.0 or
0.2ppm. and GA3 at the rate of 0.0 or 5 ppm.
The results of such expiment indicate that GA3 at the rate of 5ppm. retarded the
stimulatory effect of IBA and BA on root initiation in Scindapsus aureus cuttings.
Different treatments affected the uptake of most essential element and carbohydrate
and amino acids metabolism in Scindapsus aureus cuttings. The role of every growth
regulators in plant metabolism was discussed.
10) It could be mentioned that many growth co-factors seemed to have a role on the
rooting ability of Scindapsus aureus cuttings, as well as Philodendron scam/ens.
11) Endogenous and exogenous phenols modify plant growth in several bio-assays,
and they participate in many complicated chains of reactions which are reflected on the
whole processes of plant metabolism, including endogenous auxin and abscisic acid and the
development of the cuttings.
12) Finally, it may be concluded that different growth regulators and co-factors
affecting plant metabolism by differentces mode of actions and that play an important role in
the proportion cuttings success.