Genetics of Stay-Green Trait and Its Association with Leaf Spot Tolerance and Pod Yield in Groundnut

Abstract

Despite its importance in providing income and food for smallholder farmers, fodder for livestock, and improving soil fertility through biological nitrogen fixation, groundnut yields are lowest on farmers’ fields in Sub-Saharan Africa due to biotic and abiotic constraints. Foliar fungal diseases account for over 80% reduction in groundnut productivity in some parts of Ghana. Unfortunately, chemical control of these foliar diseases has not yielded the desired results. Meanwhile, advances in phenotyping for disease tolerance in other crops have established a strong relationship between stay-green trait and foliar disease tolerance. However, this relationship has not been explored in groundnut. This study was designed to determine the genetic control of the stay-green trait and its relationship with leaf spot disease severity in groundnut. Twenty-five advanced groundnut breeding lines with varying degrees of tolerance for leaf spot tolerance were evaluated under diseased and disease-free conditions, after which four were selected for genetic studies. Results showed significant (p<0.001) differences among the genotypes for early leaf spot (ELS), late leaf spot (LLS), leaf area under greenness (LAUG), SPAD chlorophyll meter readings (SCMR), and yield traits. Leaf spot diseases caused 4.95 t·ha−1 (64.54%) pod yield reduction in CHINESE, the widely cultivated groundnut variety in Ghana. There was a strong correlation between LAUG and ELS (r = 0.82, p<0.001) and LLS (r = 0.63, p<0.001), and genotypes that were stay-green had tolerance to both diseases. Stay-green trait in groundnut was detected to be under the control of a single recessive gene and hence may be used to select for ELS and LLS resistance.

Efficacy of pre-emergence and post-emergence herbicides for weed management in groundnut (Arachis hypogaea L.) production in Guinea Savannah

“…However, herbicide application promoted high number of pods per plant. This confirmed the finding of (Danful et al 2019) who reported that increase in pod yield of groundnut was mainly associated with increase in the weight of pods per plant, which in turn was due to higher number of pods per plant, facilitated by growth and less stress conditions.…”

Multi-locus genome-wide association studies reveal genomic regions and putative candidate genes associated with leaf spot diseases in African groundnut (Arachis hypogaea L.) germplasm

“…The soils of the research area belong to Ferric Luvisols of the Tingoli series with a brown color, moderately drained, and free from concretions (Atakora and Kwakye, 2016). The experiment was carried out in a location that is a hotspot for the disease and therefore can sufficiently discriminate between susceptible and resistant lines (Danful et al, 2019;Oteng-Frimpong et al, 2021) The accessions were arranged in lattice design with three replicates. A plot was made up of one row of 2 m long with a spacing of 0.5 m between rows and 0.2 m between plants.…”

Characterization of Groundnut (Arachis hypogaea L.) Test Locations Using Representative Testing Environments With Farmer-Preferred Traits

“…An example of the predictable and unpredictable includes soil and weather parameters, respectively. Precipitation is the main source of water for groundnut cultivation in Sub-Saharan Africa, while humidity and temperature affect leaf spot disease development (Danful et al, 2019 ; Oteng-Frimpong and Dakora, 2019 ) and growth stages (Rao et al, 1992 ; Oteng-Frimpong et al, 2019 ), respectively. Hence, the lack of significance for the interactive components of the factorial regression model suggests that the predictable components of the environments were driving the genotypes by environment.…”