Breeding leafy amaranth (Amaranthus spp.) for white rust resistance

Abstract

Identification and utilization of locally preferred vegetables and increasing dietary diversity are the most effective ways to sustainably prevent hidden hunger. Underutilized crops such as amaranth (Amaranthus spp. L.) can address the nutritional problem of society. However, its wide adoption and cultivation are restricted by a major fungal disease i.e., white rust caused by Wilsoniana bliti (Biv.) Thines (Syn. Albugo bliti), especially in the tropical and subtropical regions of the world. As genetic improvement for the development of resistant varieties is the most sustainable approach, amaranth germplasm was explored and through individual plant selection and selfings, advanced breeding lines were developed in our study. Through field screening and artificial challenge inoculation, advanced breeding lines (ABLs) with high levels of white rust resistance were identified. Further evaluation for yield and quality traits indicated significant variability in the ABLs for nutritional components such as protein content (18.19–27.50%), total phenols (568.62–1220 mg GAE /100 g DW) and FRAP antioxidant activity (559.83–1531.17 mg AAE/100 g DW). The ABLs also differed in their mineral nutrient content in terms of N (2.91–4.40%), P (0.41–0.60 %), Ca (1.60–2.40 %), S (0.25–0.32 %), Fe (831.13–1168.48 ppm), Mn (285–1146.96 ppm) and Zn (133.85–206.29 ppm). Advanced breeding lines viz., IIHR-B-AM286–17–2–8 (A. dubius), IIHR-B-AM-08–13–5–2 (A. blitum), IIHR-B-AM276–3–9–4, IIHR-B-AM65–17–3–8 and IIHR-B-AM45–6–2 (A. tricolor) with good local consumer preference with enhanced resistance to white rust were identified.