TITLE:
Adaptability and Phenotypic Stability of Resistance to Two Viral Diseases and Yield Traits in Cassava
AUTHORS:
Bernadetta Kimata, Emily Masinde, Festo Masisila, Rahim Menya, Dwasi Matondo, Midatharahally N. Maruthi, Geoffrey Mkamilo
KEYWORDS:
Cassava Brown Streak Disease, Cassava Mosaic Disease, Disease Resistance, Genotype*Environment Interaction, High Yield
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.12 No.4,
April
29,
2021
ABSTRACT: Cassava productivity is
hampered by pests and diseases including cassava mosaic
disease (CMD) and cassava brown streak disease (CBSD). The main objective of this study was to identify stable
superior genotypes that combine disease
resistance and high yield. Sixteen cassava genotypes were planted in a randomized complete block design with three
replications for six planting seasons (years) at five sites in Tanzania.
The genotypes were assessed using the additive main effect and multiplicative
interaction (AMMI) analysis, and highly significant (P by-environment
(G*E) interactions were
observed for all traits studied. Percent sum
of squares (SS) due to environment (12.66% - 85.23%) was the highest
followed by G*E (14.12% -
39.56%) for CMD foliar symptoms, root weight and dry matter. On the other hand,
% SS due to genotype (52.14% - 69.14%) was
highest followed by G*E (26.14% - 35.91%) for CBSD foliar and root symptoms indicating that the
environment and G*E greatly influenced trait expression. The most stable genotypes which combined
disease resistance and high yield were NDL 2003/31 and NDL 2003/111. The
findings of this study will give impetus for the release of new cassava
varieties that are not only high yielding but are also dually resistant to both
CMD and CBSD in different locations and sites.