PERTANIKA JOURNAL OF TROPICAL AGRICULTURAL SCIENCE

Selection of hand-pollinated seeds is a critical phase in the breeding programme of whitefly-resistant soybean. This study aimed to verify true crosses and assess whitefly resistance in soybean plants derived from crosses between a superior variety and whitefly-resistant germplasm using SSR markers. The whitefly-sensitive variety Anjasmoro was crossed with IAC 100 and G100H germplasm, serving as donors of resistance genes. Whitefly resistance in the three parental lines and 46 F1 progenies was evaluated in a greenhouse using a free-choice host test. True crosses were verified through molecular selection in the laboratory using the SSR marker Satt045. The results revealed significant differences in the intensity of whitefly-induced leaf damage among the tested genetic materials. The worst leaf damage, up to 84.7%, was shown by Anjasmoro, while germplasm IAC 100 and G100H showed no leaf damage. The intensity of leaf damage in the offspring of Anjasmoro × IAC 100 and Anjasmoro × G100H varied from 0 to 84.7%. It is hypothesised that no successful cross-pollination occurred between IAC 100 or G100H and Anjasmoro in the plants derived from unsuccessful crosses that exhibited severe leaf damage. Selection using SSR markers indicated that plants with high leaf damage intensity had the same banding pattern as Anjasmoro. In contrast, plants with low leaf damage intensity exhibited a banding pattern that combined those of Anjasmoro with IAC 100 or Anjasmoro with G100H. These findings demonstrate that SSR markers, supported by greenhouse resistance tests, are reliable for verifying true crosses in soybean breeding programmes targeting whitefly resistance.