03108naa a2200325 a 450000100080000000500110000800800410001902000220006010000240008224501180010626000090022452020100023365000120224365000130225565000140226865000140228265000120229665000100230865000130231865000220233165300160235365300210236965300150239065300130240570000190241870000180243770000260245570000190248177302820250021544352023-06-15       2023    bl uuuu     u00u1 u    #d  a978-0-323-90057-71 aPOSSO-TERRANOVA, A.  aVariation in cassava landracesbhigh levels of diversity in germplasm from central Brazil.h[electronic resource]  c2023  aAbstract: Cassava (Manihot esculenta Crantz), a tropical crop, is one of the three major tuber crops worldwide together with potato and sweet potato (Dou et al., 2021). It has been among the world?s fastest-growing food crops in the past 25 years (Hershey, 2017) and the second among major starch crops in the past 15 years, only behind maize (Vilpoux et al., 2017). Cassava was domesticated from its wild species ancestors in the New World, probably in South America. According to previous reports (Hershey et al., 1983), the Northwest part of Brazil is recognized as the center of cassava origin and as such, is characterized by having the greatest global genetic diversity. Schaal et al. (2006) established the domestication of cassava somewhere between the Brazilian states of Mato Grosso, Rondo? nia, and eastern Acre and in immediately adjacent areas in lowland Bolivia. For more information on the center of origin of cassava, see also Chapter 2 of the 1st Volume in this series. To objectively quantify this variation and its distribution, we performed a morphologic characterization of cassava varieties/landraces based on root variables, which can be easily measured on-site. We coupled our morphologic analysis with a genotyping approach that uses nextgeneration DNA sequencing to assess genetic relatedness, diversity and to unravel potential signatures of admixture generated by seed propagation. As expected, we found promising phenotypes in all surveyed localities (i.e., yellow pulp coloration) while some root-shape combinations were locality-specific. Our genotyping analysis revealed that 40% of the sampled individuals showed patterns of genetic admixture, indicating that crosspollination and seed propagation may play an important role in the propagation and diversification of the crop. Several of the varieties/landraces identified in our study have the potential to be included in further breeding and improvement programs that aim for the conservation of plant genetic resources.  aCassava  aGenomics  aGermplasm  aLandraces  aManihot  aRoots  aMandioca  aManihot Esculenta  aAcorizal-MT  aAlta Floresta-MT  aCaceres-MT  aSinop-MT1 aVILPOUX, O. F.1 aCEREDA, M. P.1 aHOOGERHEIDE, E. S. S.1 aSHARBEL, T. F.  tIn: CEREDA, M. P.; VILPOUX, O. R. Varieties and landraces: cultural practices and traditional uses. London: Academic Press, 2023. p. 225-243. chapter 11.gv. 2. (Underground Starchy Crops of South American Origin: production, Processing, Utilization and Economic Perspectives.)