Release of orange-fleshed sweetpotato (Ipomoea batatas [l.] Lam.) cultivars in Mozambique through an accelerated breeding scheme

Abstract

SUMMARYSweetpotato breeding requires at least 5 years to obtain an advanced breeding clone for further testing with the goal of cultivar release. An accelerated breeding scheme (ABS) can be feasible if the genotype × year interaction is low. The objectives of the present study were to describe an ABS for sweetpotato and to investigate the efficiency of this breeding scheme for selecting high-yielding and well-adapted orange-fleshed sweetpotato (OFSP) cultivars with high β-carotene (BC) content. More than 198 500 seeds from two crossing blocks were germinated and rapidly multiplied for evaluation in observation trials at four breeding locations in Mozambique. Breeding clones with storage root yields above 10 t/ha were advanced to preliminary and advanced yield trials across four sites and for 3 years. As a result, 64 high-yielding OFSP breeding clones were selected and evaluated in four mega-environments following a randomized complete block design with three replicates at Angónia, Chókwè, Gurúè and Umbelúzi. Data from multi-environment trials were subjected to single site and combined analysis of variance as well as to stability analysis. The genotype × environment interaction was highly significant for storage root and vine yields, dry matter (DM) and BC content. Storage root yield and DM content for 15 OFSP breeding clones ranged from 14·9 to 27·1 t/ha and from 24·8 to 32·8%, respectively. BC content, iron and zinc ranged from 5·9 to 38·4, 1·6 to 2·1 and 1·1 to 1·5 mg/100 g dry weight, respectively. The OFSP breeding clones also met the culinary tastes required by local consumers in Mozambique. The proposed ABS seems to be an attractive scheme for genetic enhancement of sweetpotato.

Participatory approaches to diversification and intensification of crop production on smallholder farms in Malawi

“…With severe incidences of micro nutrient deficiencies in the human body (WHO, 2018) the importance of biofortification of food crops is growing (Tanumihardjo et al, 2017). OFSP varieties (Andrade et al, 2016) are an example of a successful approach to combat vitamin A deficiency. Similar options for yellow cassava, iron beans, protein-rich maize and orange-maize are gaining momentum.…”

“…Better OFSP yields will enable smallholder farmers to harvest more beta-carotene per ha for home consumption or market sales to the wider rural and urban population. Breeding programs continue releasing new OFSP varieties in Africa (Andrade et al, 2016). Besides good potential yields, traits of particular importance include storability, sweet and dry taste, early maturity, drought tolerance and high beta-carotene content (Laurie et al, 2004).…”

“…Besides good potential yields, traits of particular importance include storability, sweet and dry taste, early maturity, drought tolerance and high beta-carotene content (Laurie et al, 2004). The actual yields of sweet potato in southern Africa are estimated to be as low as 3 t fresh root ha -1 in the period 2010-2014 (FAO, 2017) compared with attainable yields of 27 t ha -1 reported in Mozambique (Andrade et al, 2016) and 35 t ha -1 in Malawi (Chipungu, 2015). This shows that despite breeding efforts, smallholder farmers are often unable to benefit from yield gains from genetic improvement (Tittonell and Giller, 2013) due to other yield reducing factors.…”

Climate Change and Seed Systems of Roots, Tubers and Bananas: The Cases of Potato in Kenya and Sweetpotato in Mozambique

“…By applying the ABS, 15 new drought-tolerant OFSP varieties were released in Mozambique in 2011 (Andrade et al 2016b). An additional four OFSP varieties were released in 2016 (Andrade et al 2016c).…”

Genomics-Assisted Breeding in the CGIAR Research Program on Roots, Tubers and Bananas (RTB)

“…Activities include implementing strategies to accelerate genetic gains, improve the efficiency of breeding pipelines, and shorten breeding cycles. For instance, in sweet potato, an accelerated breeding scheme (ABS) has been developed and implemented, and has shortened the cycle by half [52], from 7-9 years to only 4, which can also be applied to the other RTB breeding programs.…”