Field Performance of Five Soybean Mutants Under Drought Stress Conditions and Molecular Analysis Using SSR Markers

Abstract

The objective s of this research w ere to evaluate (1) the performance of soybean mutant lines under drought stress condition s, and (2) the genetic diversity and relationship among the mutant lines using SSR markers. The field evaluation was conducted during the dry season of 2011 and 2012 at the experimental F arm of Mataram University, West Nusa Tenggara, Indonesia. The field experiment was set up in a randomized block design . Ten mutant lines and two control varieties were evaluated in four replications. Genetic distance among evaluated lines were determined based on allelic diversity analysis using 40 s imple sequence repeat (SSR) loci. Under drought stress conditions, two mutant lines , K dl 3 and K dl 8 , showed a better performance compared to the other ones. The h igh yielding mutant lines were K dl 3 and K dl 8, which yielded 1.75 t ha -1 and 1.69 t ha -1 , respectively, compared to the parent and national control , Panderman 1.43 t ha -1 and Muria 1.32 t ha -1 . These mutant lines required 30.75 to 32 days to flower and 79.75 to 83.75 day to harvest with relatively short plant height 28.25 and 23.35 cm respectively. T hose mutant characters were better than those of the other three mutants, the original parents, and the control soybean species. Since the evaluated soybean mutant lines yielded more under drought stress conditions than the standard varieties, t he y can be used and registered as drought-tolerant soybean mutant s . Moreover, the evaluated soybean accessions showed a wide genetic distance. The accessions were clustered into two groups according to their genetic background, namely group I (the Panderman with three mutant lines) and group II (the Muria with two mutant lines). Twenty-three out of 40 evaluated SSR loci, including AW31, BE806, CMAC7L, S080, S126, S57, S171, S224, S285 , S 294 , S 393 , S294 , S 383, S511 , S 511, S 5 20 , S 5 40, S547, S551, S571, S577, and S578, provided polymorphic alleles between the parents and their mutants and could be used to differentiate mutants from their parents. Therefore, these loci are informative and may be use ful for further analysis of soybean mutant lines in relation to breeding program.