Abstract

When genetic variability is diminished using traditional breeding methods, induced mutation is a good way to increase genetic diversity in soybean. Hence, genetic diversity amongst 33 M7 generation soybean mutant lines with high N2 fixation character and one non-irradiated cultivar (L17) was studied by using random amplified polymorphic DNA (RAPD) markers and some morphological traits. RAPDs established 104 major amplified products using 10 polymorphic primers. Out of 104 markers, 34 were monomorph and the remaining (70) were polymorph. Cluster analysis of studied lines in terms of RAPD markers, separated mutant lines group from parent cultivar. Both morphological and RAPD markers successfully detected genetic variation within induced mutant lines and the variation between irradiated and non irradiated lines which were morphologically indistinguishable also detected by RAPD. Therefore RAPD markers with average PIC = 0.80, can be more useful for detecting induced diversity among mutant lines. It can be inferred from the results that irradiation did induce significant genetic variability with regard to majority of studied traits such as number of nodule per plant and harvest index. Sequencing and cloning of band pattern (3 kb) obtained from parent cultivar with OPA09 primer and introducing it as a SCAR marker can be used in marker assisted selection.

Key words: diversity, morphological traits, mutation, random amplified polymorphic DNA, soybean