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Tripathi L.,International Institute Of Tropical Agriculture | Babirye A.,International Institute Of Tropical Agriculture | Roderick H.,University of Leeds | Tripathi J.N.,International Institute Of Tropical Agriculture | And 5 more authors.
Scientific Reports | Year: 2015

Plant parasitic nematodes impose losses of up to 70% on plantains and cooking bananas in Africa. Application of nematicides is inappropriate and resistant cultivars are unavailable. Where grown, demand for plantain is more than for other staple crops. Confined field testing demonstrated that transgenic expression of a biosafe, anti-feedant cysteine proteinase inhibitor and an anti-root invasion, non-lethal synthetic peptide confers resistance to plantain against the key nematode pests Radopholus similis and Helicotylenchus multicinctus. The best peptide transgenic line showed improved agronomic performance relative to non-transgenic controls and provided about 99% nematode resistance at harvest of the mother crop. Its yield was about 186% in comparison with the nematode challenged control non-transgenic plants based on larger bunches and diminished plant toppling in storms, due to less root damage. This is strong evidence for utilizing this resistance to support the future food security of 70 million, mainly poor Africans that depend upon plantain as a staple food.

Tripathi L.,International Institute Of Tropical Agriculture | Tripathi J.N.,International Institute Of Tropical Agriculture | Tushemereirwe W.K.,National Agriculture Research Laboratories
Acta Horticulturae | Year: 2010

The banana Xanthomonas wilt (BXW) disease, caused by the bacterium Xanthomonas campestris pv. musacearum (XCM), endangers the livelihoods of millions of farmers in the Great Lakes region of East and Central Africa. The disease was first identified in Uganda in 2001 and has since then also been reported in Eastern Democratic Republic of Congo, Rwanda, Kenya and Tanzania. The pathogen kills plants quickly and spreads rapidly over a large area making the disease one of the most dreaded in banana (Musa spp.). The development of disease resistant banana cultivars remains a high priority, since farmers are reluctant to employ labor-intensive disease control measures. Prospects of developing cultivars with resistance to BXW through conventional breeding are limited, as no source of germplasm exhibiting resistance against XCM has been identified. Transgenic technologies for banana may provide a timely and cost-effective alternative solution to the BXW pandemic. The ferredoxin-like amphipathic protein (pflp) and hypersensitive response assisting protein (hrap), isolated from sweet pepper (Capsicum annuum) are novel proteins that can intensify the harpinPSS-mediated hypersensitive response. The International Institute of Tropical Agriculture (IITA) has negotiated royalty-free license from Academia Sinica, Taiwan, patent holder, through the African Agricultural Technology Foundation (AATF) for access to the technology for bacterial wilt resistance. The partners, IITA, the National Agriculture Research Organization (NARO) in Uganda and AATF, have signed a tripartite agreement for development of BXW-resistant transgenic bananas. Hundreds of transgenic lines of banana cultivars have been generated, which are screened for disease resistance under laboratory conditions. Most promising lines will be evaluated for efficacy against XCM in fields.

Bresnahan K.A.,University of Wisconsin - Madison | Arscott S.A.,University of Wisconsin - Madison | Khanna H.,Queensland University of Technology | Arinaitwe G.,National Agriculture Research Laboratories | And 6 more authors.
Journal of Nutrition | Year: 2012

Banana is a staple crop in many regions where vitamin A deficiency is prevalent, making it a target for provitamin A biofortification.However, matrix effects may limit provitamin A bioavailability from bananas. The retinol bioefficacies of unripeand ripe bananas (study 1A), unripe high-provitamin A bananas (study 1B), and raw and cooked bananas (study 2) were determined in retinol-depleted Mongolian gerbils (n = 97/study) using positive and negative controls. After feeding a retinol-deficient diet for 6 and 4 wk in studies 1 and 2, respectively, customized diets containing 60, 30, or 15% banana were fed for 17 and 13 d, respectively. In study 1A, the hepatic retinol of the 60% ripe Cavendish group (0.52 ± 0.13 μmol retinol/liver) differed from baseline (0.65 6 0.15 mmol retinol/liver) and was higher than the negative control group (0.39 ± 0.16 μmol retinol/liver; P < 0.0065). In study 1B, no groups differed from baseline (0.65 ± 0.15 μmol retinol/liver; P = 0.20). In study 2, the 60% raw Butobe group (0.68 ± 0.17 μmol retinol/liver) differed from the 60% cooked Butobe group (0.87 ± 0.24 μmol retinol/liver); neither group differed from baseline (0.80 ± 0.27 μmol retinol/liver; P < 0.0001). Total liver retinol was higher in the groups fed cooked bananas than in those fed raw (P = 0.0027). Body weights did not differ even though gerbils ate more green, ripe, and raw bananas than cooked, suggesting a greater indigestible component. In conclusion, thermal processing, but not ripening, improves the retinol bioefficacy of bananas. Food matrix modification affects carotenoid bioavailability from provitamin A biofortification targets. © 2012 American Society for Nutrition.

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