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العنوان
Genetical and molecular studies on some potato
(Solanum tuberosum) cultivars grown under
salinity and radiation stress /
المؤلف
Awad, Amal Salah Ali.
هيئة الاعداد
باحث / Amal Salah Ali Awad
مشرف / Zakia Mohamed Adam
مشرف / Thoria Rashad Mohamed
مناقش / Awatif Ibrahim El-Nahas
تاريخ النشر
2018.
عدد الصفحات
278 P. :
اللغة
الإنجليزية
الدرجة
الدكتوراه
التخصص
علوم النبات
تاريخ الإجازة
1/1/2018
مكان الإجازة
جامعة عين شمس - كلية البنات - قسم النبات
الفهرس
Only 14 pages are availabe for public view

from 278

from 278

Abstract

The present investigation was carried out in the laboratories of the Natural Products Department, National Center for Radiation Research and Technology, Atomic Energy Authority, Nasr City, Cairo, Egypt, to study the effect of different gamma radiation doses, salinity and the combined effect between them on tissue culture derived plantlets. Some biochemical analysis , molecular genetic markers and ultrastructure in Spunta and Valor cultivars were studied. The results obtained were:
Part I - Tissue culture studies
Potato (Solanum tuberosume L.) plantlets cultured on MS medium. MS + 0.2 mg-l BAP was the best medium for micropropagation. Hormones such as NAA, KIN and GA3 with different concentrations gave slight growth.
1- Effects of different treatments on bud survival and some morphological characters in two potato cultivars (Spunta and Valor) a- Effect of gamma radiation
In two cultivars Spunta and Valor, gamma radiation doses (10, 20, 30, 40 and 50 Gy) caused decrease on buds survival and several morphological characters of Spunta and Valor cultivars. Ten Gy caused a slight decrease in bud survival percentage and shoot length. While the dose 50 Gy was the lethal dose. The dose 40 Gy considered as sub lethal dose.
b- Effect of NaCl concentrations
The salinity concentrations caused significant decrease on Spunta and Valor buds survival and some morphological characters. The concentrations 150 and 200 mM caused death of plantlets in both cultivars.
c- Effect of combined effect
The combined effect treatments caused decrease in buds survival and some morphological characters. The present results showed that the Valor cultivar was more resistante to combined treatments than Spunta cultivar.
2- In vitro production of microtubers in different potato cultivars (Spunta and Valor)
The liquid medium MS + 0.2 mg-l BAP + 8% sucrose was the best medium for microtuberization of Spunta and Valor cultivars. The formation of microtubers in control and irradiated Valor cultivar by doses 10, 20, 30 and 40Gy were more than the formation of microtubers control and irradiated treatments of Spunta cultivar by the same doses.
The usage of different NaCl concentrations 50, 75 and 100 mM caused decrease in the formation of microtubers in both cultivars. The combined effect treatments affected negatively on tuberization. Moreover, the combined effect treatments did not form any microtuber in two cultivars.
3- Acclimatization of Spunta and Valor cultivars
The acclimatization succeeded in control and irradiated treatments in Spunta and Valor cultivars plantlets by doses 10, 20, 30 and 40Gy. On the other hand, the acclimatization failed with treatments under different NaCl concentrations 50, 75 and 100 mM and combined effect treatments compared with control in both cultivars.
Part 2 : Biochemical Analysis
1-Proline content in Spunta and Valor cultivars a-Effect of gamma radiation on proline content
The different gamma radiation doses 10, 20, 30 and 40 Gy caused increase in proline content .The proline content increased in Spunta cultivar more than Valor cultivar.
b- Effect of NaCl concentrations on proline content
The usage of different NaCl concentrations 50, 75 and 100 mM induced increase in proline content. The proline content increased in Spunta cultivar more than Valor cultivar.

c- Effect of combined treatments between gamma radiation and salinity on proline content
The combined effect between gamma radiation doses and NaCl concentrations induced significant increase in proline content in both cultivars.
Part 3- Molecular Markers Analysis a- Effect of gamma radiation
The usage of RAPD as a genetic marker is still the fastest, easiest, cheapest and effective way to differentiate between varieties and treatments.Ten random decamer primers were used for determination of genetical RAPD finger printing. Total genomic DNA of ten treatments from irradiated Spunta and Valor cultivars by doses 10, 20, 30 and 40 Gy and their control. In Spunta cultivar, the primers amplified 73 bands, 43 bands were monomorphic bands, 16 bands were non unique bands and 14 bands were unique bands. The bands ranged in size between 144 bp to 1874 bp.The Maximum number of bands was 12 that was produced by the primer OP- B07, whereas the primers OP– B11, OP-L16 and OP-Z03 produced the minimum number of bands (5 bands). The polymorphism percentage was 41.09 %. The primer OP- B07 which gave the highest polymorphism percentage of bands 66.66%, while the primer OP-L12 produced the lowest polymorphism percentage of bands 14.28%.Whereas, in Valor cultivar the primers amplified 77 bands with 31.16% polymorphism percentage., 53 monomorphic bands, 18 bands were non unique and 6 were unique bands.The bands ranged in size between 13061 to 144 bp. The Maximum number of bands was 13 that was produced by the primer OP-B07, whereas the minimum number of bands was 3 was produced by the primers OP-L13, OP-L16 and OP-Z03. The primer OP-F06 which gave the highest polymorphism percentage 55.55%, while the primer OP-L12 which induced the lowest polymorphism percentage 12.50%.
All the ten primers were gave specific markers in two cultivars.
b- Effect of NaCl concentrations
The total genomic DNA of control and treated Spunta and Valor cultivars with concentrations of NaCl (50, 75 and 100 mM) were used as templates for RAPD marker. Spunta cv showed 63 amplified bands, 40 bands were monomorphic, 15 bands were polymorphic and 8 bands were unique bands.The polymorphism percentage was 70% with an averge of 31.89%, while the average polymorphism percentage of treated Valor cv was 28.45%. There were 55 reproducible bands; 37 of them were monomorphic bands,14 bands were polymormic and only 4 bands were unique band.
c- Effect of combined treatments
The ten primers amplified 70 and 85 reproducible bands with Spunta and Valor cultivars treated with combined treatments resepectively. Spunta and Valor cultivars displayed 48 and 43 monomorphic bands, 17 and 34 non unique and 4and 8 unique bands respectively. The polymorphism percentage of Spunta was ranged from 0% to 50%, while Valor cultivar showed range from 27.27% to 78.57% with average 28.48% and 47.78% respectively. The RAPD analysis exhibited average polymorphism percentage indicates moderate level of genetic diversity between control and treated groups.
Cluster analysis represented the polymorphism in a graphic dendrogram. UPGMA analysis based on RAPD profile in all treatments of radiation ,salinity and combined treatments showed that control group is very near from the least tratment dose and very far from the highest treatment dose .
2- protein banding pattern in Spunta and Valor cultivar
The combined effects between gamma radiation doses and salinity induced changes in protein banding pattern in both cultivars. The observed changes were in the total number of bands, appearance of new bands, and disappearance of some bands as compared with their relative controls
The total number of bands in Spunta cultivar were 8 bands, 6bands were monomorphic,one band was non unique with molecular weight 152.2kDa appeared in control and treatment 30Gy+50 mM. There was band with molecular weight 44.7 kDa disappeared in all the combined effect treatments. The protein bands ranged in size between 152.2 to 26.3KDa with polymorphism percentage of bands 25 %.
In Valor cultivar, the total number of bands were 13bands, seven bands were monomorphic, band was non unique with molecular weight 190.4kDa appeared in control and treatment 30Gy+ 50mM. There was 3 bands were unique bands appeared with molecular weight 106.07, 44.7 and 41.6KDa, which were appeared with treatments 30Gy + 75mM, 40Gy + 75mM and 30Gy + 100mM respectively. One band with molecular weight 55.1kDa disappeared in all the combined effect treatments.The protein bands ranged in size between 190.4 to 26.3 KDa with polymorphism percentage of bands 46.15%.
Part 4 - The ultrastucture of Valor leaves under different treatments

Scanning electron microscope (SEM) and transmission electron microscope (TEM) reported the presence of ultrastructure changes after different treatments compared with control.
Scanning electron microscope (SEM) showed that the stomata on epidermis of leaf were closed and swollen in dose 40Gy. The salt concentration 100 mM illustrated that the stomata on epidermis of leaf under salt stress were closed. Moreover, the combined treatments showed that the stomata were closed.
Transmission electron microscope (TEM) reported that the cell wall ruptured and chloroplasts showed irregular shape, rupture of chloroplasts membrane,deformation of internal structure of chloroplasts. The chloroplasts of irradiated plantlets were not arranged along plasma membrane. There was large intercellular space in mesophyll cells in irradited treatments as compared with control. Moreover, in high salinity concentration 100 mM showed that the number of chloroplast decreased. In combined treatment , chloroplast characterized by the presence of starch grains and its internal structures were deformed.