الفهرس 
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Abstract
This study was carried out in the Tissue Culture Laboratory,
Department of Horticulture, Faculty of Agriculture, Moshtohor,
Zagazig University during the period from 1995 to 1998 to study the
best possibilities of raising up some clonal nucellar citrus rootstocks
through in vitro techniques.
Homogenous certified mother trees from trifoliate orange,
rough lemon, rangpure lime, cleopatra mandarin, volkamer lemon,
and sour orange rootstocks were selected. Immature fruits were
collected at different ages following fruit setting. The collected
immature fruits were washed, surface sterilized and the nucellus
embryos were excised and cultured on different of types medium.
Callus production was initiated and increased using different auxin
types at different concentrations different additives, modifications in
medium strength, cytokinin types and thidiazuron as well as
different concentrations of BAP. Different medium strengths, GA3 at
different . concentrations, different medium states, different auxin
types with different concentrations and growth retardant were
involved in this study. The in vitro rooted plantlets were
acclimatized using different agricultural media. Furthermore, the
finger print for the rootstocks under study were performed using
SOS-PAGE.
The obtained results could be summarized as follow:
VI.I. Establishment stage
1- Nucellar embryos of trifoliate orange rootstock were superior in
plantlets regeneration ability and improved the greening while
reduced both necrosis and browning.
2- The older nucellar embryos (8 weeks-old) succeeded in increasing
plantlets regeneration and greening. However, callus production,
necrosis and browning were at the lowest level.
3- Trifoliate orange rootstock showed higher callus production
capacity from 4 weeks old embryos when cultured on Murashige
and Tucker medium.
4- Continuous increase ill auxin concentration up to 4.0mg/L
resulted in maximizing callus production. In this respect, 2,4-D
surpassed NAA.
5- Murashige and Tucker medium was superior than Murashige and
Skoog in reducing necrosis and increasing all other parameters
including, plantlets regeneration, growth, greening and medium
efficiency.
6- Malt extract was superior than other additives in improving callus
development through increasing the number of gloubs/callus,
number of somatic embryos/callus and in tum increasing number
of regenerated plantlets/callus which resulted in maximizing
plantlets regeneration efficiency. However, greening was
improved when either yeast extract or malt extract was added.
7_ Sour orange and trifoliate orange rootstocks surpassed other
rootstocks in enhancing callus development and increased
gloubs, somatic embryos, plantlets regeneration, plantlets
regeneration efficiency and greening.
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8- Half-medium strength ofMurashige and Tucker was optimum for
growth, plantlets regeneration and greening of majority of the
used rootstocks.
V.2. Proliferation stage
1- Kinetin was more effective than both BAP and thidiazuron in
enhancing growth and greening, while proliferation efficiency
was maximized by using BAP.
2- The highest proliferation of the most used citrus rootstocks was
achieved by supplementing the culture medium with either 1.0 or
2.0mg/L BAP.
V.3. Rooting stage
V.3.l. Shoot elongation
1- Application of half medium strength increased root formation
while. using one-fourth medium strength shoot elongation and
greenmg,
2- Gibberellic acid at 1.0mg/L and 2.0mg/L induced shoot
elongation, while only 2.0rng/L improved greening of trifoliate
orange.
V.3.2. Root formation
3- Liquid medium resulted introduction in necrosis and stimulated
rooting of trifoliate orange, while, solid and liquid medium states
succeeded in improving greening.
4- Indole-3-butyric acid (IBA) surpassed Naphthalene acetic acid
(NAA) in increasing greening and rooting. However, both of
IBA and NAA had similar effect on callus production, necrosis,
and shoot elongation.
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5- The low concentration of auxin (1.0mg/L) gave the lowest values
for callus production and necrosis, while enhanced shoot
elongation and greening. However, using 2.0mg/L of auxin
maximized rooting.
6- The lower coumarin concentrations (O.5mg/L and l.Omg/L)
surpassed paclobutrazol in reducing necrosis and increasing
shoot elongation, greening, and rooting.
VA. Acclimatization
Combination of soil mixture containing 330/0 peat moss + 330/0
sand + 330/0 loam was found to maximized survival percentage
which, reached up to 770/0. However, different combinations
showed a highly increase of survival percentage compared to the
use of soil any agricultural soil alone.
IV.5. Finger print
1-A specific identification of rootstocks under study was detected
using SDS-PAGE finger print. Also, different protein types and
different concentrations appeared charactarizing each rootstock in
this study.
2- A protein type number 5 (MW.49.50 KDa) may ’be used as
identifying parameter for the finger print of the citrus rootstocks.