Abstract:
Studies were conducted to assess the morphological, physiological and genetic diversity of
finger millet genotypes with respect to yield and drought tolerance in Tanzania. Alpha
lattice field experimental design was used in morphological characterization of 169
Tanzania finger millet genotypes and complete randomized design for drought and yield
evaluation experiments. Morphological descriptors used were plant height, number of
productive tillers per plant, number of fingers per panicle, number of leaves per plant, time
to plant maturity, yield per plant and thousand grain weights. Data were analyzed using
descriptive statistics and correlation matrix, dendrogram and cluster analysis techniques.
Plant yield was found to be significant (P ≤ 0.05) and positively correlated with number of
productive tillers, plant maturity, and number of fingers per panicle, finger length and
thousand grain weights. Analysis for principal component was done to determine
contributing factors to finger millet diversity. The number of tillers, thousand grain
weight, plant maturity and number of fingers per panicle were identified as important traits
contributing to diversity and yield variability among finger millet genotypes in Tanzania.
Thirteen SSR markers recovered polymorphic information content ranging from 0.31 to
0.79, indicating very high genetic diversity of the finger millet genotypes. The Markers
detected 114 private alleles, which can help in advancing molecular breeding using
techniques such as next generation sequencing to identify the genotypes possessing those
identified private alleles. Principal coordinate analysis showed 42% genotypes’ variations
within and 55% genotypes variations across locations and 3% genotypes’ variations
between locations. Cluster analysis discriminated 169 finger millet genotypes into a
phylogeny tree of 13 distinct clusters. Drought phenotyping using yield stability, drought
resistance and stress tolerance indices identified genotypes TFA 77, TFA 169 and TFA 11
to be superior drought tolerant and high yielding genotypes under terminal drought stresses. Determination of adaptation and stability of finger millet genotypes across finger
millet production agro-ecologies targeting release of improved varieties for immediate
farmers’ use in Tanzania is recommended. Integrated physiological, molecular and
morphological characterization is recommended for large number of genotypes screening
for drought tolerance using morphological and physiological traits associated with grain
yield for finger millet variety development in Tanzania.
