Screening of Soybean Advanced Breeding Lines for Resistance Against the Southern Green Stink Bug Nezara viridula L (Hemiptera: Pentatomidae) under Free-Choice and No-Choice Tests

Abstract

Background: The southern green stink bug (SGSB), Nezara viridula, is a potentially harmful pod sucker insect found in soybean. Objective: The objective of this study was to evaluate the resistance level of several soybean advanced breeding lines against the southern green stink bug N. viridula under the free-choice and no-choice tests. Methods: The research materials were 14 advanced breeding lines and four check cultivars. The experiment was conducted in Malang, East Java, Indonesia, during the dry season I and II 2022. The resistance evaluation of the soybean genotypes against the N. viridula was under the Free-Choice test (FC) and the No-Choice test (NC). The newly emerged adults N. viridula were infested when plants reached the R5 stage. The data were observed for damage intensity, yield and yield components. Results: The intensity of pod damage in the FC ranged from 20.09 to 46.40%, meanwhile, in the NC was 25.63 to 67.63%. This shows that the NC condition provides more selection pressure than the FC. Each genotype exhibited different resistance reactions in the FC and NC. The pod damage intensity had a significant negative correlation with seed yield both in the FC and NC. Conclusion: The No-Choice test (NC) provided a higher selection pressure for resistance to SGSB than the Free-Choice test (NC). The use of SGSB-resistant cultivars will prevent soybean seed yield losses. A new finding in this study, two soybean genotypes Anj/Rjbs-305 and Anj/Rjbs-306 were resistant to SGSB. Both genotypes exhibit good agronomic performance (high yield and large seed size), thus can be proposed as new soybean varieties to be developed in the country.