The World Health Organization characterized COVID-19 as a pandemic in March 2020, the second pandemic of the twenty-first century. Expanding virus populations, such as that of SARS-CoV-2, accumulate a number of narrowly shared polymorphisms, imposing a confounding effect on traditional clustering methods. In this context, approaches that reduce the complexity of the sequence space occupied by the SARS-CoV-2 population are necessary for robust clustering. Here, we propose subdividing the global SARS-CoV-2 population into six well-defined subtypes and 10 poorly represented genotypes named tentative subtypes by focusing on the widely shared polymorphisms in nonstructural (nsp3, nsp4, nsp6, nsp12, nsp13 and nsp14) cistrons and structural (spike and nucleocapsid) and accessory (ORF8) genes. The six subtypes and the additional genotypes showed amino acid replacements that might have phenotypic implications. Notably, three mutations (one of them in the Spike protein) were responsible for the geographical segregation of subtypes. We hypothesize that the virus subtypes detected in this study are records of the early stages of SARS-CoV-2 diversification that were randomly sampled to compose the virus populations around the world. The genetic structure determined for the SARS-CoV-2 population provides substantial guidelines for maximizing the effectiveness of trials for testing candidate vaccines or drugs.

16The World Health Organization characterized the COVID-19 as a pandemic in March 2020, the second 17 pandemic of the 21 st century. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a 18 positive-stranded RNA betacoronavirus of the family Coronaviridae. Expanding virus populations, as 19 that of SARS-CoV-2, accumulate a number of narrowly shared polymorphisms imposing a 20 confounding effect on traditional clustering methods. In this context, approaches that reduce the 21 complexity of the sequence space occupied by the SARS-CoV-2 population are necessary for a robust 22 clustering. Here, we proposed the subdivision of the global SARS-CoV-2 population into sixteen well-23 defined subtypes by focusing on the widely shared polymorphisms in nonstructural (nsp3, nsp4, nsp6, 24 nsp12, nsp13 and nsp14) cistrons, structural (spike and nucleocapsid) and accessory (ORF8) genes. 25Six virus subtypes were predominant in the population, but all sixteen showed amino acid 26 replacements which might have phenotypic implications. We hypothesize that the virus subtypes 27 detected in this study are records of the early stages of the SARS-CoV-2 diversification that were 28 randomly sampled to compose the virus populations around the world, a typical founder effect. The 29 genetic structure determined for the SARS-CoV-2 population provides substantial guidelines for 30 maximizing the effectiveness of trials for testing the candidate vaccines or drugs. Main 32In December 2019, a local pneumonia outbreak of initially unknown etiology was detected in 33 Wuhan (Hubei, China) and quickly determined to be caused by a novel coronavirus 1 , named Severe 34 acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 2 and the disease as COVID-19 3 . SARS- 35CoV-2 is classified in the family Coronaviridae, genus Betacoronavirus, which comprises enveloped, 36 positive stranded RNA viruses of vertebrates 2 . Two-thirds of SARS-CoVs genome is covered by the 37 ORF1ab, that encodes a large polypeptide which is cleaved into 16 nonstructural proteins (NSPs) 38 involved in replication-transcription in vesicles from endoplasmic reticulum (ER)-derived 39 membranes 4,5 . The last third of the virus genome encodes four essential structural proteins: spike (S), 40 envelope (E), membrane (M), nucleocapsid (N) and several accessory proteins that interfere with the 41 host innate immune response 6 . 42Populations of RNA viruses evolve rapidly due to their large population sizes, short generation 43 times, and high mutation rates, this latter being a consequence of the RNA-dependent RNA 44 polymerase (RdRP) which lacks the proofreading activity 7 . In fact, virus populations are composed of 45 a broad spectrum of closely related genetic variants resembling one or more master sequences [8][9][10] . 46 Mutation rates inferred for SARS-CoVs are considered moderate 11,12 due to the independent 47 proofreading activity 13 . However, the large SARS-CoV genomes (from 27 to 31 kb) 14 provide to them 48 the ability to explore the sequence spa...

In recent decades, the expansion of soybean production in Brazil has been observed. This advance was motivated by the search of environments with better cultivation conditions, as well as the development of genotypes with wide adaptation. The diversity of "environments" hinders the process of selection and recommendation of cultivars, since the productive potential of a cultivar is given as a function of the sum of the genotype effect, the environment and the interaction between the latter two (G x E). In the case of this G x E interaction, regional studies are necessary in order to detail the differential behavior of the cultivars. Thus, the objective of this work was to evaluate the genotype interaction by environments, adaptability and phenotypic stability for grain yield, of fifteen soybean cultivars, in four sowing seasons, in order to identify cultivars that combine high productive potential, predictability of behavior and adaptation to the edaphoclimatic conditions of Uberlândia-MG. The trials were conducted at the Experimental Farm Capim Branco, in Uberlândia-MG. Fifteen soybean cultivars were evaluated in four sowing seasons (October 23, 2016, November 19, 2016, December 10, 2016 and January 14, 2017), in relation to grain yield. The experimental design was of randomized complete blocks, with three replications, in each season. Data were submitted to individual and joint analyzes. The G x E interaction was decomposed by the method proposed by Cruz and Castoldi (1991). The differential behavior of the genotypes was detailed by the adaptability and phenotypic stability by the methods of Eberhart and Russell (1966), Lin and Binns (1988) modified by Carneiro (1998), AMMI and Centroid. By the analysis of joint variance, it was observed the existence of the cultivar interaction by sowing times (C x E), for the grain yield trait, at the 5 % probability level by the F test. The C x E was predominantly complex in nature. The cultivar CD 2737 RR presented satisfactory results for the four sowing seasons in Uberlândia-MG, with high grain yield and predictability of behavior, by the evaluated methods. The cultivar NS 6909 IPRO was classified into favorable environments by the methods of Eberhart and Russell (1966) and Lin and Binns (1988) modified by Carneiro (1998). Considering Lin and Binns (1988) modified by Carneiro (1998) and Centroid the cultivar that is also classified for this cultivation condition is UFUS 8301. By AMMI, UFUS 7415, CD 2737 RR and UFUS Milionária are considered stable and adaptable.