Not AvailableDevelopment of kunitz trypsin inhibitor (KTI)-free soybean is crucial for soy-food industry as the heat inactivation employed to inactivate the anti-nutritional factor in regular soybean incurs extra cost and affects protein
solubility. In the presented work, a null allele of KTI from PI542044 was introgressed into cultivar ‘JS97-52’
(recurrent parent) through marker assisted backcrossing. Foreground selection in BC1F2, BC2F2 and BC3F2
was carried out using the null allele-specifc marker in tandem with SSR marker Satt228, tightly linked with a
trypsin inhibitor Ti locus. Background selection in null allele-carrying plants through 106 polymorphic SSR
markers across the genome led to the identifcation of 9 KTI-free lines exhibiting 98.6% average recurrent
parent genome content (RPGC) after three backcrosses, which otherwise had required 5–6 backcrosses
through conventional method. Introgressed lines (ILs) were free from KTI and yielded at par with recurrent
parent. Reduction of 68.8–83.5% in trypsin inhibitor content (TIC) in ILs compared to the recurrent parent
(‘JS97-52’) was attributed to the elimination of KTI.DB