الفهرس 
Effect of salt stress on growth and physiological processes of banana plantOnly 14 pages are availabe for public view
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Abstract
This investigation was carried out to study the effect of gamma irradiation, salinity and
interaction between them on. banana cultivars, Williams and Grand Nain using tissue culture
technique. MS medium supplemented with growth regulators was used during this course of
studu. The results obtained could be summarized as follows:
1- Effect of gamma irradiation on banana cultivars a- growth parameters
Banana cultivars (Williams and Grand Nain were exposed to 0, 20, 40 and 60 Gy. With increasing
gamma irradiation doses:
- Survival percentage, number ofleaves/plant and length of plant have decreased in vitro.
-Number of roots and length of root decreased.
- All growth parameters of ex vitro (survival percentage, Number of leaves and length of plants
were reduced on exposure to gamma irradiation.
b- physiological characters of banana cultivars
-There was a decrease in photosynthetic pigments (chlorophyll a, chlorophyll b,and corotenoids)with
increasing gamma irradiation doses both in vitro and ex vitro.
- Gamma irradiation reduced total souble sugars, reducing sugars and nonreducing sugars of banana
cultivars both in vitro and ex vitro.
- Polyphenol oxidase and peroxidase activities wereincreased at low doses of gamma irradiation but
at higher irradiation doses there were significant decrease.
- There was an increase in phenolic compounds due to the increase in exposure doses both in vitro
and ex vitro.
- At low doses of gamma irradiation protein content was increased and at high doses the content was
decreased.
- Proline concentration was increased significantly in both cultivars as the irradiation doses
increased up to 40 Gy but at 60 Gy the reverse was occurred.
2- Effect of sodium chloride concentration on banana cultivars
a- Growth parameters
Banana cultivars i.e.Williams and Grand Nain were treated with · NaCl,the concentrations used were
0, 2000, 4000 and 6000 ppm.
- Survival percentage, number of leaves I plants and length of
plant in vitro growth were decreased with increasing NaCl concentration
- Growth of root (no. of roots and length of root )was decreased
significantly with increasing NaCl concentration up to 4000ppm. High level 6000ppm caused death to
all treated plants.
- Low concentration (2000ppm)of NaCl in irrigated water caused a significant decrease in all growth
parameters studied of ex vitro. Higher concentrations of salts (4000 - 6000ppm) caused death of
plants.
b- Physiological characters of banana cultivars
-Photosynthetic pigments i.e. (Chlorophyll a, chlorophyll band carotenoids) were decreased
significantly with increasing NaCl concentrations in vitro at ex vitro plants.
-NaCl concentration caused a reduction in reducing sugars, non reducing sugar and total soluble
sugar both in vitro and ex vitro plants.
- Polyphenol oxidase and Peroxidase activities in vitro plants were increased at (2000-4000ppm)
NaCl, while a sharp decrease
in activity has been occurred at high concentration (6000 ppm). Ex vitro plants showed an increase
in the activity of both polyphenol oxidase and peroxidase at 2000 ppm, while 4000- 6000ppm caused
death of all plants.
-Phenolic compounds were significantly increased with
increasing NaCl concentration both in vitro and ex vitro plants.
-At concentrations of2000-4000ppm NaCl protein contents was increased. However at higher
concentration 6000ppm NaCl protein content was decreased in vitro plant. In ex vitro plant protein
content was increased at 2000ppp NaCl, while higher concentration ofNaCl caused death of plants.
-Proline concentration was increased at low concentration of
NaCl (2000-4000 ppm) while at high doses (6000ppm) proline content was sharply decreased in vitro
growth. Meanwhile, proline content with (2000 ppm NaCl)was increased.Whereas 4000-6000 ppm caused
death of plants.
3 Interaction effect of gamma irradiation and salinity a- growth parameters
Shoot buds of banana cultivars (Williams and Grand Nain) were exposed to combination between
different doses of gamma irradiation i.e. 0, 20, 40 and 60 Gy and different NaCl I.e.
concentrations 0, 2000, 4000 and 6000 ppm ..
-Survival percentage, number ofleaves and length of plants were decreased with increasing
irradiation doses and NaCl concentration.
-Growth of root was decreased significantly with increased gamma irradiation doses and NaCl
concentrations.
-There was a significant decrease in all growth parameters that recorded on ex vitro plants.
-Plants treated with the interaction of20 Gy and 2000ppm NaCl showed enhancement in growth over all
interaction treatments used.
-At 40 Gy I 4000ppm NaCl there was a slight increase in growth
parameters compared to 4000ppm NaCl treated plants.
b- Physiological characters of banana cultivars
-Photosynthetic pigments (chlorophyll a, band carotenoid) were decreased with increasing
interaction between gamma irradiation and NaCl concentrations.
- Carbohydrate fractions were. decreased significantly with
increasing interaction between gamma irradiation and NaCl ·
concentrations.
,_•·)
- Polyphenol oxidase and peroxidase enzymes showed an· · increase in the activity at low doses of
gamma irradiation and 11 NaCl concentrations, while higher levels of irradiation and salts i
showed a sharp decrease in the activity. ···
-Phenolic compounds were increased with increasing gamma i·
irradiation and NaCl concentrations. _;J
-Interaction between gamma irradiation and salinity caused ari·JJ increase of protein content at
low dose of irradiation and low ”i NaCl concentration, but below protein content of control
plants,+ while at high doses the protein content decreased. ·.
-There was a slight increase in proline content at low doses of:? both irradiation and NaCl
concentrations, while at higher doses
and higher concentration there were a sharp decreases. ·’
4- SDS-PAGE protein electrophoresis
- Control plant of Williams cultivars showed bands of
. molecular weight 123.07, 54.35 and 38.20 KDa.
-40 Gy treated plants showed absence of 54.35KDa and existant of the band 54.06 KDa beside the
presence of bands of molecular weight 123.07 and 38.20 KDa.
-Treatments of 4000ppm, 40Gy X 2000ppm and 20 Gy X 4000
ppm showed absance of band with molecular weight 38.20 KDa and a new band of molecular weight 38.05
was existed in addition to bands 123.07 and 54.06 KDa.
-40 Gy with 4000ppm NaCl showed appearance of two other
· proteins bands with molecular weights 68.57 and 28.18 KDa beside 123.07, 54.06 and
38.05KDa bands.
5- Anatomical studies
Cross section of leaf blade of in vitro and ex vitro banana cultivar Williams showed that.
-There was a reduction in the area of cross section of leaf blade with increasing doses of
irradiation.
-Increasing salt concentration caused generally a reduction in
anatomical parameters.
-Interaction between gamma irradiation and salinity caused a decrease in the area of cross section
of leaf blade, shrinkage and collapse of cells and irregularities in cell shape at high doses of
irradiation and salt concentrations.
-In vitro leaf anatomy resembled hydrophyte leaf anatomy
owing to plants development in an aqueous medium while this character was lessened after
acclimatization.
In vitro and ex vitro banana cultivars studied were rather sensitive to radiation and salinity;
Williams cultivar showed rather more sensitivity than Grand Nain cultivar,