早期木薯储存根的形成和膨胀是农民和加工者倾向于在干旱等非生物和生物胁迫的情况下采用的一种逃避媒介,洪水,和家畜的破坏。在这项研究中,来自国际热带农业研究所(IITA)的220种木薯基因型,国家根部作物研究所(NRCRI),国际热带农业中心(CIAT)当地农民(来自农民的田地),和NextGen项目在三个地点进行了评估(Umudike,Benue,和Ikenne)。这些试验是使用随机不完全区组设计(α晶格)中的分裂图进行的,在2年内重复两次。在种植(MAP)后3、6、9和12个月取样或收获每种植物基因型的储存根。使用R-统计软件包分析收集的所有数据。结果表明,性状之间的遗传力中等到高,各基因型间表现存在显著差异(p<0.05)。使用BLINK模型的全基因组关联作图检测到45个单核苷酸多态性(SNP)标记与染色体1、2、3、4、5、6、8、9、10、13、14、17和18上的四个早期储存根膨胀和形成性状显着相关。发现总共199个推定的候选基因与早期储存根膨胀和形成直接相关。这些候选基因的功能被进一步表征为调节i)植物激素生物合成,ii)细胞生长和发育,和iii)用于积累淀粉和防御的次级代谢产物的生物合成。全基因组关联研究(GWAS)还揭示了四个多效性SNP的存在,控制淀粉含量,干物质含量,干产率,以及膨胀和地层指数。有关GWAS的信息可用于育种者开发改良的木薯品种。选择五种基因型(W94006,NR090146,TMS982123,TMS13F1060P0014和NR010161)作为整个植物年龄的最佳早期储存根膨胀和形成基因型。这些选定的品种应在未来的育种计划中用作早期储存根膨胀和形成的来源。
Early
cassava storage root formation and bulking is a medium of escape that farmers and processors tend to adopt in cases of abiotic and biotic stresses like drought, flood, and destruction by domestic animals. In this study, 220
cassava genotypes from the International Institute of Tropical Agriculture (IITA), National Root Crops Research Institute (NRCRI), International Center for Tropical Agriculture (CIAT), local farmers (from farmer\'s field), and NextGen project were evaluated in three locations (Umudike, Benue, and Ikenne). The trials were laid out using a split plot in a randomized incomplete block design (alpha lattice) with two replications in 2 years. The storage roots for each plant genotype were sampled or harvested at 3, 6, 9, and 12 month after planting (MAP). All data collected were analyzed using the R-statistical package. The result showed moderate to high heritability among the traits, and there were significant differences (p< 0.05) among the performances of the genotypes. The genome-wide association mapping using the BLINK model detected 45 single-nucleotide polymorphism (SNP) markers significantly associated with the four early storage root bulking and formation traits on Chromosomes 1, 2, 3, 4, 5, 6, 8, 9, 10, 13, 14, 17, and 18. A total of 199 putative candidate genes were found to be directly linked to early storage root bulking and formation. The functions of these candidate genes were further characterized to regulate i) phytohormone biosynthesis, ii) cellular growth and development, and iii) biosynthesis of secondary metabolites for accumulation of starch and defense. Genome-wide association study (GWAS) also revealed the presence of four pleiotropic SNPs, which control starch content, dry matter content, dry yield, and bulking and formation index. The information on the GWAS could be used to develop improved
cassava cultivars by breeders. Five genotypes (W940006, NR090146, TMS982123, TMS13F1060P0014, and NR010161) were selected as the best early storage root bulking and formation genotypes across the plant age. These selected cultivars should be used as sources of early storage root bulking and formation in future breeding programs.