Marker assisted accelerated introgression of null allele of kunitz trypsin inhibitor in soybean

Abstract

Development 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-specific 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 identification 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.

Trypsin Inhibitor Assessment with Biochemical and Molecular Markers in a Soybean Germplasm Collection and Hybrid Populations for Seed Quality Improvement

“…Finally, segregants with ti3/ti3 genotypes were successfully verified for low KTI content and propagated for further yield analysis and development of prospective breeding lines. Our results were similar to those published earlier on the introgression of the null-allele ti3 and MAS to select recombinant genotypes with low KTI content in an Indian soybean breeding program [16,17]. Hybridization and transference of the beneficial ti3 null-alleles determining low KTI in seeds using MAS is very important to enhance the market value and overall soybean seed quality in Kazakhstan.…”

“…The best local soybean cultivars from Kazakhstan were Lastochka and Ivushka, with moderately high KTI and showing 54. 16 and 54.87 units/mg of TUI, respectively, but these were still significantly higher than Hilario and Ascasubi. (Table 2).…”

“…The introgression of the ti null-allele at BC 2 F 2 and BC 3 F 2 generations was controlled by Marker-assisted selection (MAS) with ti allele-specific primers and linked SSR markers. Nine and six breeding lines with genetic backgrounds of JS97-52 and DS9712 / DS9814 recurrent parents, respectively, were obtained in Indian breeding programs [16,17]. The introgressed null-allele ti was confirmed in the breeding lines and the KTI content was reduced by 69-84% [16] and an additional seed yield improvement was reported [17].…”

From proteomics to ionomics: Soybean genetic improvement for better food safety

“…chromosome 9) and gene specific primers are available now for assisting in the introgression of that trait (e.g. ALVES DE MORAES et al, 2006;KIM et al, 2006;RANI et al, 2011;KUMAR et al, 2013;KUMAR et al, 2015;MARANNA et al, 2016).…”

Current Status and Prospects of Genomic Selection in Legumes

“…In the case of pea, Aphanomyces root rot resistance QTLs (Lavaud et al 2015) and frost tolerance QTLs (Hascoët et al 2014) were introgressed using MABC into different agronomically important genetic backgrounds. Likewise in soybean, MABC was deployed successfully to improve resistance to a defoliating insect (Zhu et al 2007), bacterial leaf pustule resistance (Kim et al 2008) and to reducing a kunitz trypsin inhibitor (Kumar et al 2015).…”