International Journal of Advanced Engineering Research and Science (IJAERS) Peer-Reviewed Journal ISSN: 2349-6495(P) | 2456-1908(O) Vol-10, Issue-12; Dec, 2023 Journal Home Page Available: https://ijaers.com/ Article DOI: https://dx.doi.org/10.22161/ijaers.1012.8 www.ijaers.com Page | 79 Stability and Adaptation of Soya Strains Based on different Models in the North and Northeast Regions Guilherme Raposo Teixeira 1 , Luiz Henrique de Freitas Barbosa 2 , Angelo Ricardo Balduino 3 , Luan Henrique Guarido da Silva 4 1 Department of Agronomy, Tocantnense Institute President Antonio Carlos, Brazil Email: raposo.agro@hotmail.com 2 Department of Agronomy, Tocantnense Institute President Antonio Carlos, Brazil 3 Department of Agronomy, Tocantnense Institute President Antonio Carlos, Brazil 4 Department of Agronomy, Soy Genetics, Brazil Received: 15 Oct 2023, Receive in revised form: 25 Nov 2023, Accepted: 06 Dec 2023, Available online: 12 Dec 2023 ©2023 The Author(s). Published by AI Publication. This is an open access article under the CC BY license (https://creativecommons.org/licenses/by/4.0/). Keywords— Glycine max. Heritability. REML/BLUP. Harmonic mean. Abstract— In Brazil, soya is the most important annual crop and is grown in a variety of environmental conditions. The environmental effect segregates the growing regions, where each one has its own peculiarities, and it is therefore the responsibility of genetic improvement programmes to meet the demand for new cultivars that overcome the instabilities and take advantage of the beneficial conditions of these environments. The aim of this study was to assess the productivity, adaptation and stability of soya strains in VCU trials. A randomised block design with three replications was used, in which six strains and two commercial cultivars were part of the trials in the cities of Cariri-TO, Caseara-TO, Aparecida do Rio Negro-TO, Porto Nacional-TO, Balsas-MA and Barreiras-BA, in the 2022/23 harvest. The REML/BLUP variational modelling method was used to analyse the data, estimate genetic parameters and predict genotypic values via MHPRVG. Significance was observed for genotypic effects and double interaction. The average heritability was adequate for the type of data set, which showed high accuracy. The genotype x location interaction showed a high coefficient of determination and the opposite was observed for the correlation, demonstrating the great influence of this effect on the results, thus highlighting its importance for the study, according to genetic parameters estimated via various models. According to the BLUPs for MHPRVG, the SOY 03 strain showed the best behaviour compared to the others and could be used as a cultivar. I. INTRODUCTION The soya bean, Glycine max (L.) Merrill, is an annual plant grown worldwide to produce oil and protein. Originally from the north-eastern Chinese region, it belongs to the Fabaceae family, where it has been cultivated for millennia. In this region, there are estimates that indicate that the plant has been used for human and animal consumption for more than 5,500 years and is considered by local traditions to be one of the five sacred grains (SEDIYAMA, 2016). Originally from a temperate climate, it has been widely adapted to subtropical and tropical regions, showing obvious plasticity, which has led to research into its behaviour in a wide range of fields of study, especially plant breeding (SEDIYAMA, 2016). In Brazil, the first reports of its introduction and cultivation date back to 1882, in Bahia, for fodder use.