SELECTION AND VALIDATION OF M4 SOYBEAN MUTANT LINES THROUGH MULTICHARACTERS APPROACH

Abstract

Mutation breeding is more effective than conventional breeding when the existing breeding material has a narrow genetic base and the scarcity of germplasm to specific desired characters. Assembling superior soybean cultivars through mutation breeding requires an effective selection method since the selection for productivity only proved less effective. Therefore, the selection base needs to be broad and use multi-characters. The latest study aimed to analyze the effectiveness of the multi-characters approach in the selection and validation process of M4 soybean mutant lines. This study evaluated M4 and M5 mutant lines for various traits at the Citayam and Muara Experimental Garden, Bogor, Indonesia. The M4 and M5 mutant evaluations used an augmented design with 121 experimental units (172 lines and four check cultivars) and a randomized complete block design with 99 experimental units (29 lines and four check cultivars), respectively. Measured variables included the number of branches, filled pods, empty pods, and productive internodes, the weight of 100 seeds, and the seed weight per sampling plot. The result showed that the correlated multi-characters were effective for selection in the soybean mutant lines. The most effective secondary character resulted from the number of filled pods. Measuring the selection effectiveness continued up to the fifth generation (M5) to further validate the selected material. In total, nine mutant lines, i.e., A182-13, A179-1, A220-156, A196-57, A186-27, A190-38, A180-6, A195-50, and A188-32, attained selection with significant genetic potential for further study through the yield test.