Cassava Yield Stability and Genetic Traits in Tropical Humid Regions

Jenn Hoskins
20th July, 2024

Cassava Yield Stability and Genetic Traits in Tropical Humid Regions

Image Source: Natural Science News, 2024

Key Findings

  • The study evaluated 12 cassava genotypes across 12 environments in Bahia, Brazil, focusing on fresh root yield (FRY) and dry matter content (DMC)
  • Genotypes BR11-34–41 and BR11-34–69 showed high performance and stability for FRY, while BRS Novo Horizonte, BR12-107–002, and BR11-24–156 excelled in DMC
  • The study identified two mega-environments for FRY and one for DMC, indicating different environmental influences on these traits
Cassava, a staple crop for millions in sub-Saharan Africa and other regions, faces significant challenges due to genotype versus environment (G × E) interactions. These interactions can lead to performance variations that hinder the selection of superior genotypes. A recent study by the Universidade Federal do Recôncavo da Bahia aimed to evaluate different stability methods to quantify G × E in multi-environment trials, ultimately identifying stable and high-performing cassava genotypes[1]. The study assessed 12 cassava genotypes across 12 environments using a randomized block design with three replicates. Key traits analyzed included fresh root yield (FRY) and dry matter content (DMC). By employing various stability methods such as additive main-effects and multiplicative interaction (AMMI), main effect of genotypes plus G × E (GGE), and weighted average of absolute scores (WAASB), the researchers aimed to identify genotypes with high agronomic performance and stability. Analysis of variance showed that the sum of squares (SQ) for genotypes, environment, and G × E effects were equally distributed for FRY. However, for DMC, these effects accounted for 64.1%, 21.9%, and 13.8% of the SQ, respectively, indicating a lower environmental effect on this trait. Using the AMMI, GGE, and WAASB methods, the study identified genotypes with high performance and stability for FRY (BR11-34–41 and BR11-34–69) and DMC (BRS Novo Horizonte, BR12-107–002, and BR11-24–156). The broad-sense heritability for FRY and DMC was estimated to be 0.45 and 0.75, respectively. Approximately 72% of the methods identified BRS Novo Horizonte as the genotype with the highest stability and performance for DMC, while 47% identified genotypes BR11-34–41 and BR11-34–69 for FRY and intermediate DMC. Genotype BR11-24–156 exhibited high static stability according to 50% of the methods. Significant correlations between stability and agronomic performance across different methods enabled the formation of groups based on stability concepts. Additionally, the study found two mega-environments for FRY, whereas DMC displayed a single mega-environment, indicating an absence of G × E. This study builds on previous research that highlighted the importance of evaluating genotype by environment interactions in cassava breeding[2]. Earlier studies have shown that environmental effects can significantly influence traits such as fresh root yield and dry matter content, necessitating multi-environment trials to identify stable genotypes[2]. Moreover, the findings align with efforts to develop cassava varieties enriched with provitamin A carotenoids, which also face challenges due to genotype by environment interactions[3]. By employing advanced stability methods, the study by the Universidade Federal do Recôncavo da Bahia provides a robust framework for identifying superior cassava genotypes that can be promoted to national performance trials. These findings are crucial for developing stable cultivars with better yield attributes, ultimately contributing to improved food security and nutritional outcomes in regions reliant on cassava as a staple crop.

AgricultureGeneticsPlant Science

References

Main Study

1) Stability and genetic parameters for cassava yield attributes in the tropical humid region of Brazil

Published 19th July, 2024

https://doi.org/10.1007/s10681-024-03384-5

Related Studies

2) Genotype by Environment Interaction on Resistance to Cassava Green Mite Associated Traits and Effects on Yield Performance of Cassava Genotypes in Nigeria.

https://doi.org/10.3389/fpls.2020.572200

3) Stability and genotype by environment interaction of provitamin A carotenoid and dry matter content in cassava in Uganda.

https://doi.org/10.1270/jsbbs.16004


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