Genotype plus genotype-by-environment interaction analysis of Soybean (glycine max (l. merrill) across production environments in Southern Africa.
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Date
2021
Authors
Nachilima, Christabell
Journal Title
Journal ISSN
Volume Title
Publisher
The University of Zambia
Abstract
Yield is a quantitative trait known to be influenced by changes in the environment in which the
crop is grown, suggesting the need to evaluate soybean lines in different growing regions to assess
their adaptability and stability. The objective of this study were to: (i) Determine yield
stability and Genotype by Environment Interaction of soybean lines across testing environments
in Zambia and Malawi using GGE biplots, (ii) Estimate broad-sense heritability for phenology,
lodging, shattering, hundred seed weight (HSW) and seed yield, and (ii) Understand multiple
trait associations among soybean lines grown in six environments in Malawi and Zambia. Sixty
two soybean genotypes were evaluated in six locations in 2018 and 2019 growing seasons, using
a 6 x 5 and 5 x 5 alpha lattice design, the collected data was analysed using a GGE biplot.. The
additive main effect and multiplicative interaction model (AMMI) indicated that environments,
genotypes and GEI significantly (P<0.001) affected grain yield and contributed 14.4 %, 1.0%
and 5.1 %, respectively, to the total variation. Whereas E4 (Kabwe and SEEDCO.Zambia) was
the most representative environment, E1 (Chipata and Chitedze) and E3 (Bvumbwe) were the
most discriminating. Thus, E1 and E3 could be used to test for local adaption and selection of
Parents. Bvumbwe in Malawi (E3) was the most informative test environment hence it is ideal
for selecting broadly adapted genotypes. Out of the 62 genotypes that were tested TGx2002 4DM,
TGx2002 8FM, TGx2001 11DM, and TGx2014 24FM were highly stable across the tested environments
in Malawi and Zambia. Genotype TGX 2014-24FM was identified as the ideal genotype
with high yield mean performance and high stability. Therefore, it could be recommended for
cultivar release in multiple environments. Plant height, days to maturity, and days to flowering
which were positively correlated to yield, had higher heritability of 50%, 75%, and 76%,
respectively, than yield suggesting that they could be used to indirectly select for yield
Description
Thesis
Keywords
Soyabean , Soybean lines. , Soyabean production.