الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
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Summary
The relationship between the two soil b~ne fungi
fW!!ar~~ oxysP.9Y}DJlf. sp. fab.- Yu and :rang, and Cephalosporium
acremonium Corda as wilt pathogens to broad
bean ( Vicia Ieba L.), and grain sorghum (Sorghum b1color
Moench), respectively was studied. The results -could be summarized as fo1lows:-
I - Broad bean:
1) The healthy and diseased roots, hypocot1l, and ep1-
cotyl at different ages grown in tubes and pots
were histologically studied.
2) In regard to diseased plants ( in dishes), penetration
of the root, hypocotyl and base of epicotyl
occurred directly through the epidermal cells,in
between two epidermal cells, in addition, penetration
also occurred through the ~ot hairs.
3) After penetration ( in tubes) hyphae developed
intercellularly and intracellularly witbin tbe
cortex of the root until reacbing the x11 •• vessela,
which were seen plugged. In older agee, cortical
•
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cells began to collapse, and the percentage of
plugged xylem vessels increased in the successive
older ages. There was a decrease in diameters
af cortex, vascular cylinder, and pith ,
and in number and diameter of xylem v •••• ls in
diseased roots than in healthY ones due to retardation
of the secondary growth in tbe,forller.
4) In pota, the collapse of cells successivel1
increased according to the age of the root, and
finally, there was a general collapse ,and
xylem vessels and adjacent oells were plugged.
In contrast to the diseased root grown ,in tube,
percentage of plugged xylem vessels of the diseased
ropt grown in pots decreased in the successive
older ages.
5) The effect of the pathogen wa’ prominent on roots
grown in tubes than on those grown in pot ••
6) D,iseased lateral roots in tub •• or pots •• re ••• -
ller, a’ expected, than the healtbY on•• , glob~
lar bodies were seen in the cortical cella of
the former.
7) Hypocotyl of diseased plant was _ller in di.etel’
than in the healthy on., xyl ••••••• 1. nuab.r and
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diameter were also smaller and their plugging was
pronounced. The outer layers of the cortex were
collapsed.
8) In diseaoed epicotyls of plants grown in tubes,
hyph~e were not detected , but the effect of
the pathogen waS greater than in the root system,
there was a severe collapse in the cortex, and a
great decrease in number and diameter of xylem
vessels which were almost plugged.
9) In epicotyJs of older ages grown in pots, tbe collapse
of cells increased, and the percentage of
plugging decreased due to the increase in secondary
xy~em vessels which was retarded in diseased
plants ~han in the healthy ones.
II- -Gr-a-in--s-or-gh-u-m-:
10) The diseased radiole root grown in tube resembled
the healthy one in structure , penetrat10n occurred
in between two 81>1d81’11al c8118 by a hypha with nallen
tip,
1:1
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11) At older ages, hyphae aggregated in the cortez
of the root. then penetrated the endoder.mis causing
darken~ng of its cells, and extended to the YaSC~
ular cylinder especially the xy1 •• v•••• ls• No
plugging of xylem vessels -.& observea. At th.
age of 12 days , the root b.gan to deteriorate.
12) .In the mesocotyl of diseased plant- grown in
tube • the disease deYeloped atml1ar17 to that
in the root, except the preseence at a dark material
1p the intercellular space. ot tbe oortex,
and plugging of xyl- vessels was pronounoed.
13) In colt!Pptile and leat blades, there were longitudinal
streaks due to the (lark.ning ot the •••-
eular bundles, and bJpbae were .eeD b.twe.n the
eoleoptile and the outer leaf and among the inner.