de Carvalho Ravena Rocha Bessa, Bandeira E Sousa Massaine, de Oliveira Luciana Alves, de Oliveira Eder Jorge
Centro de Ciências Agrárias, Ambientais e Biológicas, Universidade Federal do Recôncavo da Bahia, Cruz das Almas, BA 44380-000 Brazil.
Embrapa Mandioca e Fruticultura, Nugene, Cruz das Almas, BA 44380-000 Brazil.
Euphytica. 2022;218(12):173. doi: 10.1007/s10681-022-03125-6. Epub 2022 Nov 17.
Increasing carotenoid content and improving other root quality traits has been the focus of cassava biofortification. This study aimed to (i) evaluate the genetic variability for total carotenoid content (TCC), as well as for root yield and root quality attributes; (ii) estimate potentially useful correlations for selection; and (iii) select parents for breeding and estimate the genetic gain. Data from 2011 to 2020 of 265 cassava genotypes with cream and yellow roots were analyzed for dry matter content (DMC), shoot yield, fresh root yield (FRY), dry root yield (DRY), harvest index, average number of roots per plant, starch content, root pulp color, cyanogenic compounds, and TCC. The best linear unbiased predictions showed great phenotypic variation for all traits. Six distinct groups were formed for productive characteristics of root quality, mainly TCC, DMC and FRY. Only TCC showed high broad-sense heritability ( = 0.72), while the other traits had low to medium magnitude (0.21 ≤ ≤ 0.60). TCC was strongly correlated with pulp color (r = 0.70), but null significance for DMC. The network analysis identified a clear separation between the agronomic and quality attributes of cassava roots. The selection of the 30 genotypes for recombination in the breeding program has the potential to raise TCC by 27.05% and reduce the cyanogenic compounds content by 23.03%, in addition to increasing FRY and DRY by 22.72% and 22.95%, respectively. This is the first consolidated study on the potential of germplasm for the development biofortified cassava cultivars in Brazil.
提高木薯类胡萝卜素含量并改善其他块根品质性状一直是木薯生物强化的重点。本研究旨在：（i）评估总类胡萝卜素含量（TCC）、块根产量和块根品质属性的遗传变异性；（ii）估计选择时可能有用的相关性；（iii）选择育种亲本并估计遗传增益。分析了2011年至2020年期间265个具有奶油色和黄色块根的木薯基因型的数据，包括干物质含量（DMC）、地上部产量、鲜块根产量（FRY）、干块根产量（DRY）、收获指数、单株平均根数、淀粉含量、块根髓颜色、氰化物和TCC。最佳线性无偏预测显示所有性状均表现出很大的表型变异。根据块根品质的生产特性形成了六个不同的组，主要是TCC、DMC和FRY。只有TCC表现出较高的广义遗传力（ = 0.72），而其他性状的广义遗传力较低至中等（0.21 ≤ ≤ 0.60）。TCC与髓颜色密切相关（r = 0.70），但与DMC无显著相关性。网络分析确定了木薯块根农艺性状和品质性状之间的明显分离。在育种计划中选择30个基因型进行重组，除了分别使FRY和DRY提高22.72%和22.95%外，还有可能使TCC提高27.05%，并使氰化物含量降低23.03%。这是巴西关于种质资源在开发生物强化木薯品种方面潜力的第一项综合研究。
