Genetic Improvement of Local Cucumber Variety (Cucumis sativus L.) Using Back Crossing Method

Abboud  al-Jasem
General Commission for Scientific Agricultural Research-
Raqqa  Research Center
Faculty of Agriculture, Aleppo University,
2006

Abstract

Five varieties are used in this study: one local variety and other four imported varieties (Condor, Pabilon, Prince, and Freed).
The results were analyzed by computer to get the least signification different (L.S.D). The plants were grown in small plastic bags (10 cm cross), and they were transplanted into the ground. Male and female flowers were separated from the selected plants to make inbreeding pollination and back crossing with used tongs. The plants were sprayed with GA3 acid, 1500 ppm twice, at the first and second stages of leaf formation at one week interval.
The studied characteristics were:
(1) early flowering and maturation.
(2) length, diameter, weight and fruits number per plant.
(3) production kg/dunum.
(4) characteristics of the biological fruits to its length, diameter, weight and seeds weight.
(5) average seeds per fruit.
(6) average of 1000 seeds per fruit.
Four local strains were separated, one of them has white color fruit. Four self-pollination strains inbreeding are developed from imported cucumber varieties. More information on the characteristics of early-matured and produced local strains, whereas the developed strains high-quality fruits. The ability of GA3 acid at 1500 ppm to form male flowers in the female cucumber plants was testes and the results were good. The plants that can tolerate to powdery mildew disease were separated. Good initial matter for selection of new cucumber varieties had been formed.
Cucumber is considered as a kid of vegetables. It is widespread and used all over the world. The harvest of cucumber is good and the period of growing is short. It can be eaten directly, and it can be used in salads.
The cucumber contains different nutritional elements and enzymes, which help digest the food. The salts present in cucumber help balance blood sourness. It also increases the pissing process and helps in the disposal of stones from blabber and  kidney.
The local cucumber variety is considered the most famous one because it has a very special and delicious taste. It is tolerant to temperature differences between day and night and it resistant to thirst. However, growing this variety is reducing year by year because of its poor production and diseases.
All these things pushed the farmers to replace it by high-yielding hybrids. Developing new local varieties to be used on new hybrid varieties of cucumber is our aim. Moreover, the back crossing for local cucumber is a foreign variety, which may save the expenses of the imported hybrid seeds.
The research has been done by both Aleppo University and the General Commission for Scientific Agricultural Research because we don’t have specialized centers to produce vegetable seeds as cucumber, for pure strains produce to use later in genetic improvement programs and new hybrid or varieties of cucumber.
The research aimed to:
(1) study and characterize local cucumber variety.
(2) develop new inbreed strains of local cucumber variety and imported varieties to be  used later in growing new hybrids of cucumber.
(3) and make initial matter used to produce new early and productive varieties of cucumber, but we have to make sure that the form and the taste won’t be changed in the back crossing of local cucumber and imported varieties.
The research was carried out in collaboration with Faculty of Agriculture, Aleppo University and the General Commission for Scientific Agricultural Research, Raqqa Research Center during 2003-2005.