Genetic variability of soybean (Glycine max L. Merrill) genotypes for pod shattering resistance

Consumer demand for soybean (Glycine max L. Merrill) is not only high yielding variety, but also must be in accordance with industrial preferences, primarily for its shattering resistance. A total of 16 soybean lines were evaluated in Nganjuk, East Java, Indonesia from Feb to May 2018. The pod shattering evaluation was using oven-dry method. All tested lines have large seed size, except SAT-Ng-A4. Five lines have early days to maturity (< 80 d). The highest yielding line and large seeded size was SAT-Ng-AG-3 (4.06 t ha^-1), but it has medium maturity. Pod shattering evaluation which using a gradient system of temperature showed that oven temperature of 50 °C and 60 °C were able to differentiate the soybean resistance to pod shattering. Three very resistant lines and one resistant line were obtained after exposed to 60 °C. The soybean pods which allowed to dry at room temperature for 9 d and exposed to high temperature (80 °C) showed high variability on shattering resistance. Three resistant lines (SAT-Ng-A4, SAT-Ng-6-13, and SAT-Ng-5-5) were obtained from screening on both oven methods. Those three lines with high yield, large seed size, and medium maturity can be used as parental lines to improve soybean shattering resistance in the breeding program.