تحليل التنوع الوراثي لبعض أصناف الرز .Oryza sativa L باستخدام بعض المؤشرات الجزيئية

Analysis of genetic diversity of some rice cultiver Oryza sativa L. using some molecular markers

Genetic diversity of eleven cultivars and five genotypes of rice (Oryza sativa L), using molecular markers and morphological parameters through an experiment in collaboration with Mashkhab Research Center in AL-Najaf Data of morphological traits were calculated e.g. (plant height, Panicles length, plant age, weight of 1000 grains and grains yield)which showed high variation between cultivars genetic varieties and genetic compositions for all above mentioned traits.
The use of Polymerase Chain Reaction(PCR) based on the marker Simple Sequence Repeats (SSR) ,The DNA was isolated from fresh leaves of rice plant after 25 days from sowing using Genomic DNA plant kit Protocol . The amount of isolated was DNA as sailable amomnt rangea rangd 125-589 ng/μl with purity of 1.8to 1.9 . after agarose gel electrophoresis and staining with ethidium bromide. Results showed that there were 149 alleles by using 27 primers. The range of molecular size 66.873 -1015.402 bp . RM3412 and RM335 primers were the highest number of alleles 9 produced while the lowest number of alleles was 2 alleles recorded by RM201 ,RM10772, RM236 and RM122 primers. The Polymorphism information content (PIC), which is the a reflection of allelic diversity and allelic repetition between cultivars ranged value between 0.0587- 0.8595. As range of genetic dimension values between (0.0605-0.8730). Primers RM7443 Produced the highest value of Heterozygot with 0.8000. two primers (RM8085 and RM224) gave a distinctive genetic fingerprinting of 4 varieties and genotypes under study. The lowest genetic distance 0.4259 between the first and the second genotypes this means that there is a high degree of similarity between these genotype. Ggenetic similarity of percente all cultivars and genotype ranged between 0.0793 – 0.5741 depending on the genetic distance that ranging from 0.4259 – 0.9207 which refers to the large genetic diversity ranged from 42% – 92% .This reveals a high genetic variation between cultivars making hereditary good sources. Results also showed that Cluster analysis of seven major groups Main Cluster at the level distance scale of 0.12, they were not distributed randomly, but its distribution was common ancestor, and this is due to the efficiency of SSR marker in the detection of genetic diversity in rice plant.
By using Simple Sequence Repeats SSR it is possible able to detect quantitative traits loci that associated with drought tolerance and salinity resistance genes and bacterial leaf blight resistance genes caused by bacteria Xanthomonas oryzaepv.oryzae (Xoo). Sheath blight rice resistance genes caused by Rhizoctonia solani fungus , resistance genes was for some biotype brown plant hopper of the disease Nilaparvata lugens Stal. ,the resistance genes for some biotype disease gall midge resistance caused by an insect Orseolia oryzae (Wood-Mason).