Marker-assisted selection for development of kunitz trypsin inhibitorfree soybean varieties: I. Parental polymorphism survey using SSR markers

Abstract

Soybean is regarded as “miracle bean” due to its numerous uses as food, feed and health supplement. However, acceptance of soy foods has been restricted by the presence of kunitz trypsin inhibitor (KTI) in soybean seeds. Kunitz trypsin inhibitor also known as SBTI-A2 which constitutes 80% of the total trypsin inhibitor activity, has been shown to be responsible for growth inhibition, pancreatic hypertrophy and hyperplasia in experimental animals [1-3]. Though KTI is heat labile, however, heat treatment is not only cost ineffective but also results in approximately 20% decline in protein solubility [4]. Similarly, boiling of beans prior to grinding with wheat (1:9) is essential while preparing soy-supplemented chapatti flour. Therefore, development of KTI-free soybean varieties which are not yet available in India is expected to boost utilization of soybean in food products.