‫ والء مصطفى محمد مصطفى عيسى‬-1
‫دراسات وراثية و جزيئيه على المقاومه لمرض اللفحة فى األرز‬
Walaa Moustafa Mohammed Moustafa Essa
Genetic and molecular studies on blast resistance in rice (Oryza sativa L.)
ABSTRACT
Rice blast is one of the most important diseases, caused by the fungus (Pyricularia oryza), it consider one of the most serious
constraints to rice production is not only in Egypt but in many rice growing countries. Five local rice (Oryza sativa L) varieties i.e. Giza
177, Sakha 105, Sakha 104, Sakha 101 and Sakha 103 as well as two introduced varieties Puebla and Hispgran in half diallel were
used; therefore, twenty one F1 hybrids were obtained. Vegetative characters as well as, yield and its components for all genotypes
under study were measured to estimate combining ability, heritability and heterosis in parents and their F1 hybrids. Also, study the
relationship between some morphological characters and the yield and its components by estimating correlation coefficient among
the mentioned characters.
Moreover, study the genetic diversity among the used varieties using 20 RAPD primers and 12 SSR primers and determine the
genetic differences among seven rice varieties using RAPD and SSR markers and assessment the genetic distance and relationships
among these varieties which could help in the development of breeding programs. According to the results Sakha 101 × Hispgran
was found to be the best cross followed by Giza 177 × Sakha 101. SSR and RAPD makers detected the genetic variability and it could
be a great help to make finger print to the seven varieties. Two primers gave band in the resistance varieties and not in the susceptible
so, in the future study by using F2, these bands could be used as a markers related to resistance gene for blast disease.
Key words: Rice blast, Pyricularia oryza, Oryza satia, RAPD, SSR.