الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
~e present study was conducted during two
consecutive seasons, 1985 and 1986 at the Faculty
of Agriculture Moshtohor, Zagazig University,
Kalubia Governorate.
Bio_fertilization studies have called the
attention toward soil microorganisms as a good
alternative to chemical fertilization because of
its cheep costs and it causes no pollution. Mycorrhizal
fungi is considered as one of the biefertilizers
which live between plant rootS.
Consequently, this investigation was carried
out, to study the effect of endomycorrhizal fungi
inoculation and phosphorus fertilization on soil
properties, infection and intensity, mycorrhizal
dependency ratio (MDR) of rootstock, dry weight of
different parts of seedlings, top/root ratio, root
growth and distribution, leaf and root minerals
content, leaf chlorophyll and carotene contents,
leaf sugars and stem total carbohydrates, leaf and
root amino acids content, and leaf cyto~inins
content of two citrus rootstocks.
Two-year-old seedlings of two citrus rootstocks,
i.e. Cleopatra mandarin and sour orange were
transplanted in woody boxes filled with clay loam
soil disinfected with 2% Formalin solution (2 Seedlings
per each box).
The treatments used in this study involved I
1. Boxes left untreated as control.
2. Boxes fertilized with phosphorus at the rate
of 5g P205 as superphosphate (control).
3. Boxes unfertilized with P but the soil Was
inoculated with glEm~ m~££E£§rp~fungi.
4. Boxes unfertilized with P but soil was inoculated
with Glo.!!\l~1..!§!!i~£~ fungi.
5. Boxes fertilized with phosphorus at the rate of
5g P205 as superphosphate and the soil Was
inoculated with g12m~.§m~££9~§EPus fungi.
6. Boxes fertilized with phosphorus at the rate of
5g P205 as superphosphate and the soil Was
inoculated with Q1Em~§ ~ustrale fungi.
On the other hand, other set of seedlings were
planted in 30 cm diameter clay pots treated with
mycorrhizae and fertilized with phosphorus with the
same rate for boxes for the infection and intensi’t7
stUdies.
The obtained results could be summerized as
follows :
5.1 IDfecUoD I
1. Mycelium and arbuscules of mycorrhizae
fuugi on roots of Cleopatra mandarin and sour
orange started with low percentages in May
followed by a gradual increase in July to
reach the maximum (l~) in September. However,
in both rootstocks vesicles percentages on
citrus roots were almost l~ in all sampling
dates.
2. Mycelium, vesicles, and arbuscules on roots
of control rootstocks used were nil.
:3. In May and July, seedl~. inoculated with
mycorrhizae fuugi and unfertilized with phosphorU8
gave hip;herpercentages of myc.eliWll aDd arbuscules
on their roots as compared to that of inoclllated
and fertilized ones.
4. Generally, in all sapling dates, $ll0!!l1lS
austrw fwl8i was associated with higher percentages
of arbusclllesthaD ’su’CPM 88&rocarplMl
mycorrhi ••••
179
5.2. Intensity:
1. Number of mycelium. vesicles. and arbuscules
on roots of the two studied citrus rootstocks
started with low numbers in May followed by an
increase in July and a sudden increase in September.
2. Citrus seedlings inoculated with mycorrhizae
and unfertilized with phosphorus had roots with
higher number of mycelium. vesicles. and arbuscules
as compared with those treated with mycorrhizae
and fertilized with phosnhorus.
3. Glomus australe fungi caused a hip;her increase
in number of vesicles and arbuscules on
rootl or o1trua rootltocks aore thaD ~QlY’
macrocarpus mycorrhizae. On the other hand,
the effect of mycorrhizae species on ayc.li_
number depended upon the rootstock Wled. In
this respect, whUe GlomUS aLl!trW funsi were
superior in increasing number of mycelium on
roots of Cleopatra mandarin seedl1Dgs as coapared
to GlomW! macrocarpy!!. the picture was
changed to the opposite when lour oraus. s.84-
1illgs were concerned.
5.3. ~corrhizal dependency ratio (1IlJil) I
1. Cleopatra mandarin dependecl51.ightly_
on mycorrhizae than sour orange rootstock.
2. QJ,0l!I!.l1 .9lacfocarplWf’UJ:l6iwas more effective
on MDR of seedlings than the .Ql..£I!l.9!
austral,!! fungi.
3. Applying phosphorus to citrus seedlings
decreased visually MDR as compared to unfertilized
plants.
1. Higher Values of dry weight parameters
were observed for sour orange seedlings as
compared to Cleopatra mandarin.
2. Mycorrhizae fungi treatments increased cU7
weight of different parts of seed.l1np:s and top/
root ratio as compared to control plants •
.ilO!!lW! lIacfocarpW! flUUl:iwas 1I0re prOlllis1ng
in iDCreasi~ dr;y weights of whole seed.lilUl.,
leaves, stem and roots than ’suQ!I,Y! ,,,,trw.
Such reSQIt was not clearly noticed ror top/
root ratio.
3. Applying phosphorus only to citrus Seed-
1111gscaused. s1gn1finant 1Dcreue ill cU7
.
weight of roots whereas other parameters of
dry weight used in this study were decreased
under phosphorus fertilization.
5.5. Boot growth :
1. Cleopatra mandarin and sour orange seedlings
unfertilized with phosphorus and inoculated
with lilolll,.mWa!crocarpus fungi gave
higher Values of root growth expressed as
root coefficient.
2. Cleopatra mandarin seedlings gave general.Q’
higher Values of root growth as cOlllparedto the
analogouS ones of sour orange rootstock.
3. Generally as a Spec1tic effect of mycorrhizal
fungi. Glomus austral, enhanced better
root growth of citrus seedl~8 than GIO!i!
iterooarpYi fun~i under the experimental 8011
environment.
4. Unfertilized seedlings with phosphorus
8urpas8ed in their root growth the P fertUize4
ones.
5.6. Root distribution ,
1. Cleopatra mandarin seedlings inoculated
With GIOJllusaustraJ& fungi and unt’ertilized
with phosphorus was preferable cOJllbination
for encouraging root distribution of plants
among the other treatments used whUe sour
orange seedlings received phosphorus and
treated with GIOJllusmacrocarRB!! fungi surpassed
all other treatments relDaTkably in this
respect.
2. Cleopatra mandarin plants had higher number
of 3-5 m.m. and 2-3 m.m. roots whereas sour
orange seedlings were Superior in 1-2 m.m. roots
and total number of roots.
3. Mycorrhizae fungi treatments increased s1g_
n1ficantly root number of different diameters
and total root number. In the same time, ~!,y
macrocarpy’! fungi wart more promising in increasing
number of’1-2 m.m. and 3-5 a.m. roots.
On the other hand, ~.Y§ ~.&U III¥corrhi••e
f’ungi. encouraged developing of’2-3 m.m. roots
and total number of’roots.
4. P unfertilized seedliDgs not only increased
root number of different diameters but also the
total number of roots than fertilized seedlings.
5.? Lea:t1Il1neJ.’aclosntent :
1. Generally 10weJ.’amounts of N and Ca and were
higher levels of K and Zn/existed in leaves
of sour orange rootstock as compared with those
of Cleopatra mandarin. No statistioidifference
between the two rootstocks used was observed
concerniDg leaf P and Mg contents.
2. Mycorrhizae species raised up Leaf N. P, I,
and Kg contents and decreased lea:t Oa and 2Q
contents in respect of contJ.’olplants. GlaRy!
austrai§ fungi were more positive in stimulating
leaf p. K. and Mg contents than Gl!Ml\Llm!acJ.’ocarpus
spec~e. The significant difference was
lackiDg in case of leaf N and Oa contents.
3. Phosphorus fertilizer eitheJ.’added for SOUl.’
oJ.’aDgeOJ.’Cleopatra mandarin seedlings increased
lea:t p. K. and Oa contents and decJ.’easedlea:t _,
JIg. and Zn l.”els.
5.8. Root minerals content I
1. Control seedliDKs fertilized with phosphorus
had roots with higher amounts of N and P and
lower levels of K and Mgas coapared with unfertilized
control plants. No clear trend or difference
was noticed in case of zn anrl Ca nutrients.
2. Roots of sour or~e seedliDKs contained
higher amounts of N, K, Ca, Mg, and zn
than those of Cleopatra mandarin seedliDKs
which were more rich in root P content.
3. ~corrhizae fungi decreased root P, Ca, Mg,
and zn contents and in the S8llletime increased JIT
and K levels as compared with non inoculated
seedlings (control). §lomus austrw flUlgi had
increased root N and zn contents aDd
decreased root P, K, Ca, and JIg levels. lio
significant difference was observed betweeo
the two species of I117corrhiz.e in their effect
on root minerals content.
4. Phosphorus fertilization 1Dcreased JIT aDdP
contents of citrus rootstocks whilst it had no
effect on root K, Ca, Mg, and 2’.D since the
difference was small.
5.9. Leaf chlorop~ll and carotene contents :
1. Leaves of sour orange seed1iDP;scontained
higher amounts of chlorop~ll (A) and total
chlorophyll and lower level of carotene in
respect of Cleopatra mandarin. Citrus sPecie.
s had no statistical effect on leaf
chlorophyll (B).
2. Mycorrhizae species used were promising in
building up more leaf chlorophyll and carotene
over the control. Meanwhile. G10ll1!laSustaale
1’uIlll:ias comparedwith Glom!lSmacrocarpys decreased
leaf chlorophyll (A) and carotene whilst
they increased leaf chlorop~ll (B) and total
chloropb.vll. Such effect was not statistical17
observed in case of leaf total chlorop~ll.
3. ceedlings receiving phosphoru. were iD1’erior
in their leaf chlorop~ll and carotene contents.
However, significant di1’1’ereaces were
lacking whenleaf chlorop~ll (B) end carotene
contents were concerned.
186
5.10. Leaf susars and stem total carbohydrates :
1. Sour orange seedlings had leaves with
higher amounts of non redu~and total susars
as iliellas stem total carbohydrates in respect
of those of Cleopatra mandarin. Leaf
reducUg sugars of sour orange wereslightly
less than those of Cleopatra mandarin.
2. ,@,omlas.!,!ustralf,u§ngi decreased significantly
leaf non-redu~ and total sugars
and slightly reducUlg susars than the control.
3. Applying phosphorus to citrus plants induced
a significant decrease in leaf non-reduciag
sugars but it had no statistical effect on leaf
reduciJtgand total sugars as well as stem total
carbohydrat es•
5.11.Leaf nitrogen fractions :
1. Leaves of Cleopatra mandarin seedlillgs
contained higher amounts of soluble nitrogen,
rest nitrogen, and ammonium nitrogen and lower
level of crystalloid nitrogen as compared with
those of sour orange. Citrus rootstocks had no
statistical effect on leaf nitrate content.
2. Comparing £llomus!!§.crocarpusfungi treatment
with the control, it significantly decreased
leaf crystalloid nitrogen and nitrate contents
as well as increased leaf rest nitrogen but
without any effect on leaf soluble nitrogen
and ammonium nitrogen contents. Glomus aus~.!
fungi, from other hand, increased leaf
crystalloid nitrogen and ammonium nitro~en and
decreased leaf rest nitrogen and nitrate contents.
3. Phosphorus application decreased leaf soluble
nitrogen, rest nitrogen and nitrate contents and
increased leaf ammonium nitrogen. Phosphorus,
by all means, had no effect on leaf CJ:,Ystall01d
nitrop;en.
5.12 Boot nitrogen fract10DB :
1. Roots of Sour orange seedlinp;swere more
rich in soluble nitro~en and poor in nitrate
content in respect of Cleopatra mandarin. No
visual difference was observed between sour
orange and Cleopatra mandarin regarding root
crystalloid nitrogen, rest nitr08en, BDd
emaonium nitrogen confents.
2. )fycorrhiaae 1’uDgifluctuated in their e1’fec_
on root nitrogen fractions content. In this
concern, Glomus australe fungi succeeded
in increasing root soluble nitrogen, cr,ystal10id
nitrogen, rest nitrogen, and nitrate
contents whereas ~s macrocarRU’ fungi
raised up only root rest nitrogen, and nitrate
contents. Both two mycorrhizae fungi used in
this study failed to increase root ammonium
nitrogen over the control.
3. Adding phosnhorus to citrus seedlinp;s increased
only root nitrate content whilst it decreased
the other root nitrogen tractions determined
in this study.
5.13 Leaf and root •.ino acids conten’ I
1. Cleopatra mandarin seedlings generally gave
hill:hervalues of leaf and root _inc acids content
than those of sour orange.
2. l’ unfertilized but mycorrhisae inoculated
plants of both rootstocks were hisher in their
values of leaf •.ino acids content than corresponding
uni.noculated ones.1he opposite w•• t~Qe
whan ~corrhi..u fllDgi and fertilized seedlings were
caapared with fertilized control ones.
3. Glomusaustral,!! fu.ogi resulted in an
increase in leaf amino acids content than
Glomusmacroc~ mycorrhizae.
4. Leucine and Isoleucine, Proline, and
Hydro.xyProline existed in citrus leaves with
higher amounts whereas leaf Valine, T,yrosine,
Threonine, Glysine, Arginine, and Histidine
showedan opposite trend.
5. Cleopatra mandarin and sour orange seedli.
ogs fertilized with phoRohorus and inoculated
with Glom~ macrocarpul fungi gave higher values
of root amino acids content than those unfertilized
and inoculated with the seme mycorrhizae
fungi.
6. M3’corrhizae fungi treatments increased root
amino acids level as COJllparedto non-inoculated
control plants. At all ”’ents, GJ.oags aac£OCarpg
fungi were more promisi.og in increasiug root
emino acids content than GleaM austrMe.
7. !pplyiDg phosphorus to citrus seedlings
induced a general inerease in root -.ino acids
content as coapared with unfertiliZed and. !lbat
was true in either inoculated or non-inoculated
plants.
8. Leucine and Isoleucine. Proline. and
Uydroxy Proline were hi~her in roots of citrus
seedli~s wnilst Valine. ~hreonine. Glysine.
Arginine. and Histidine were inferior in roots
of citrus rootstocks studied in this research.
5.14 Leaf cytokiniDa content I
1. .Applying phosphorus to control seedliJ:Igs
decreased leaf cytokinins content in June but
in September the effect was changed to the
reverse. Such result was more clear in case
of Cleopatra mandarin rootstock.
2. Inoculati~ P unfertilized plants With
mycDrrhizae increased leaf cytokinins content
in both June and September samples. In sour
orange rootstock such effect was not so 8tro~
as in Cleopatra mAndarin.
,. jpplyinl ph08phoru8 to inoclllatecl8Hdlqa
of both citru. rootstocks iDCre ••eclleat c71iokinins
content in Sept_ber as coapered with P
unfertilized and inoculated plants. The picture
was chaDKedto the reverse in June.
4. GlomuslIlacrocarpus fungi raised up leaf
total cytokinins content in June in respect
of GlolllQsaustrale fungi. The opposite was
generally true whenleaves were sampled in
Septelilber.
5. Leaf total cytokinins content was highest
in June then decreased r6lllarkably in Sept6lllber.
5.15 8011 propertle. I
1. At the termination of the experilllent, analysis
of soil showedthat phosphorWifertUization
for Cleopatra lIlandarin resulted in an increase
in available N and a.decrease in F, K, Ca, and
1IIg nutrients. In the case of sour orange, pho-
8~horus fertilization decreased 80il available
N, P, and Ca contents and. increased avaUable
K.
2. Adding G1Cll!RlIulascrocarpWlfuugi for unfertilized
soil of Cleopatra lIlandarin 1J:Iducedan
increase in its contents of avaUable 1f, P, and
Ca and a decrease in soU K 8Dd Irs levels. In
addition. Glomus aqstrale was superior in
increasing soil available nutrients discarding
P. Moreover. inoculating unfertilized soil of
sour orange with mycorrhizae generally increased
available macro-nutrients in the soil.
3· Soil fertilized with phospho~us and treated
with Q!omu§ mac~carpus fungi contained higher
levels of available N. p. and Ca.
Similarly. m.~ aqstral! mycorrhizae
caused an increase in soil available N. p.
and Ca contents and a decrease in soil K level.
mandarin and Sour orange
Generally. inoculation of Cleopatra/ seedlings
grown in stere1ized soil with endomycorrhizal fungi
enhanced vegetative growth. root growth and distribution.
and Chemical constituents of bo~h Cleopatra
mandarin and sour orange seedl1nP:s. lPnrthemore •
.9.lC!llH! australe fungi and no phosnhorus fertilization
for Cleopatra mandarin seedlings and Gl.~
,acrocarpus fungi and no phosnhorus fertilization
for sour orange plants gave the best results of seedlings
growth.
Therefore. Gl.qs maerocarPUI or .§l-BI llWIYW
fun~i could be used as bio-fertilization for citrus
seedlings in fuaigated clay loam soil for producing
good seedlings free from diseases.