AUTHOR=Sampaio Filho Juraci Souza , Olivoto Tiago , Campos Marcos de Souza , Oliveira Eder Jorge de 

TITLE=Multi-trait selection in multi-environments for performance and stability in cassava genotypes

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1282221

DOI=10.3389/fpls.2023.1282221

ISSN=1664-462X

ABSTRACT=<p>Genotype-environment interaction (GEI) presents challenges when aiming to select optimal cassava genotypes, often due to biased genetic estimates. Various strategies have been proposed to address the need for simultaneous improvements in multiple traits, while accounting for performance and yield stability. Among these methods are mean performance and stability (MPS) and the multi-trait mean performance and stability index (MTMPS), both utilizing linear mixed models. This study’s objective was to assess genetic variation and GEI effects on fresh root yield (FRY), along with three primary and three secondary traits. A comprehensive evaluation of 22 genotypes was conducted using a randomized complete block design with three replicates across 47 distinct environments (year x location) in Brazil. The broad-sense heritability (<inline-formula><mml:math display="inline" id="im1" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mi>H</mml:mi><mml:mn>2</mml:mn></mml:msup></mml:mrow></mml:math></inline-formula>) averaged 0.37 for primary traits and 0.44 for secondary traits, with plot-based heritability (<inline-formula><mml:math display="inline" id="im2" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msubsup><mml:mi>h</mml:mi><mml:mrow><mml:mi>m</mml:mi><mml:mi>ɡ</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msubsup><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:math></inline-formula> consistently exceeding 0.90 for all traits. The high extent of GEI variance (<inline-formula><mml:math display="inline" id="im3" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msubsup><mml:mi>σ</mml:mi><mml:mrow><mml:mi>ɡ</mml:mi><mml:mi>x</mml:mi><mml:mi>e</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msubsup></mml:mrow></mml:math></inline-formula>) demonstrates the GEI effect on the expression of these traits. The dominant analytic factor <inline-formula><mml:math display="inline" id="im4" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mi>F</mml:mi><mml:msub><mml:mi>A</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:mrow></mml:math></inline-formula>) accounted for over 85% of the total variance, and the communality (ɧ) surpassed 87% for all traits. These values collectively suggest a substantial capacity for genetic variance explanation. In Cluster 1, composed of remarkably productive and stable genotypes for primary traits, genotypes BRS Novo Horizonte and BR11-34-69 emerged as prime candidates for FRY enhancement, while BRS Novo Horizonte and BR12-107-002 were indicated for optimizing dry matter content. Moreover, MTMPS, employing a selection intensity of 30%, identified seven genotypes distinguished by heightened stability. This selection encompassed innovative genotypes chosen based on regression variance index (<inline-formula><mml:math display="inline" id="im5" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msubsup><mml:mi>S</mml:mi><mml:mrow><mml:mi>d</mml:mi><mml:mi>i</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msubsup></mml:mrow></mml:math></inline-formula>, <inline-formula><mml:math display="inline" id="im6" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mi>R</mml:mi><mml:mn>2</mml:mn></mml:msup></mml:mrow></mml:math></inline-formula>, and RMSE) considerations for multiple traits. In essence, incorporating methodologies that account for stability and productive performance can significantly bolster the credibility of recommendations for novel cassava cultivars.</p>