Evaluation of Genetic Distance of Tomato Lines using ISSR Marker

The study of genetic diversity with the help of molecular markers is the main precondition and an important step in the improvement of vegetable plants, including tomato and is the basis for the effective use of heterosis and the protection of genetic pools. Several studies have been conducted using molecular markers between different tomato lines, but there is little studies in Iran. Based on this, the present study intends to estimate the genetic distance between a numbers of tomato lines using ISSR molecular markers.

In the present study, 12 tomato lines were investigated using microsatellite primers (ISSR) at Sari University of Agricultural Sciences and Natural Resources. Polymerase chain reaction (PCR) was performed by ISSR primers and PCR products fractioned on 1.5% using agarose gel electrophoresis then the bands were analysed.

The primers used showed acceptable polymorphism (85.28) and suitable score able banding patterns. The highest and lowest polymorphism information content (PIC) with values of 0.40 and 0.22 were related to ISSR2 and ISSR10 primers, respectively. The ISSR2 primer was more efficient than other primers in identifying and classifying the studied lines. The degree of genetic similarity varied from 0.23 to 0.95 between the studied lines and lines Fanal and Harlekyn had the most similarity and lines CP with Bibor and after that SP with Bibor showed greatest genetic distances. Results of cluster analysis and evaluation of quantitative characterestics of studied lines showed that genotypes 4, 5, 6 and 8 placed in first group had better yield and earliness comparing other genotypes.   

Lines CP, SP and Bibor had a great genetic distance from each other and hybridization between CP and SP with Bibor as well as utilizing of selected genotypes in first group is recommended for next breeding programs in tomato. The ISSR2 primer has useful information in distinguishing the studied lines than other primers and its useful in breeding programs of tomato.