Genetic control of resistance to rosette virus disease in groundnut (Arachis hypogaea L.)

Abstract

Groundnut rosette disease is one of the most damaging diseases militating against groundnut production in sub-Saharan Africa. The disease cause up to 100% yield loss whenever epidemic occurs. The most effective, economic and environmental friendly method to control the disease is through genetic resistance. Knowledge on inheritance of resistance to the rosette disease is required to accelerate breeding of resistant varieties. A study was conducted to understand the nature and magnitude of gene effect of resistance to the disease. Thus F 1 , RF 1 , F 2 , RF 2 , BC 1 , RBC 1 , BC 2 , and RBC 2 progenies were derived from crosses of Otuhia × Manipintar, Otuhia × Shitaochi, ICGV 01276 × Manipintar, and ICGV 01276 × Shitaochi along with their parents were evaluated in a randomized complete block design at CSIR -CRI, Fumesua, under artificial infection. Generation mean analysis revealed that additive gene action effect was predominant on the resistance to the disease in all the crosses. Additive by dominance was the only form of non-allelic interaction observed to be significant in ICGV 01276 × Manipintar cross. Reciprocal differences suggested the presence of maternal effect involved in the inheritance of resistance to groundnut rosette disease. Estimates of broad and narrow sense heritability indicated that genetic effect was larger than the environmental effects in this study. Disease diagnosis using TAS ELISA revealed the presence of groundnut rosette assistor virus (GRAV) antigens in the resistant samples analyzed. Resistant genotypes containing GRAV were considered to be resistant to the GRV and its Sat-RNA, but not the GRAV which causes no obvious symptoms by itself. Pure line breeding with selection from early generation is suggested for the improvement of resistance to rosette virus disease, because additive genetic effect contributed significantly in controlling the inheritance of resistance to groundnut rosette disease (GRD).

Yield and Disease Responses of Improved Groundnut Genotypes Under Natural Disease Infection in Northern Uganda: Implication for Groundnut Disease Management

“…The correlation of AUDPC for LLS and GRD with LLS and GRD severity was significantly positive as expected since LLS and GRD are epidemic diseases (Amoah et al, 2016). Orondo et al ( 2007) reported similar observations for AUDPC of groundnut groups Virginia, Valencia and Spanish for rosette and leaf spot resistance in Kenya.…”

Sweet potato yield and quality characteristics affected by different late‐season irrigation levels

“…In the test area, using the FAO 56 Penman Monteith equation (Eqn (1)) and daily meteorological data, the reference evapotranspiration (ET 0 ) was calculated in the test region. 35 The crop evapotranspiration (ET c ) was calculated using Eqn (2). When soil water content in the 0-20 cm layer is below 60% of the field moisture capacity, irrigation is conducted using Eqns (3) and ( 4), with supplementary irrigation every 7-10 days.…”

“…where ET 0 is the reference evapotranspiration (mm day −1 ); R n is the net radiation (MJ m −2 day −1 ); G is the soil heat flux (MJ m −2 day −1 ); γ is the psychrometric constant (kPa °C−1 ); T is the mean air temperature at 2 m height (°C); u 2 is the wind speed at 2 m height (m s −1 ); e s is the saturation vapor pressure (kPa); e a is the actual vapor pressure (kPa) and Δ is the slope of the vapor pressure curve (kPa °C−1 ); ET c is the daily crop evapotranspiration (mm day −1 ); K c is the crop growth coefficient, exhibiting variability based on the growth stage (for sweet potato, this coefficient ranges from 0.65 to 1.16) 35 ; n is the number of days between irrigation events; ET m is the cumulative crop evapotranspiration during the monitoring period (mm); I is the irrigation amount (mm); and P is the effective precipitation (mm). Effective rainfall is defined as rainfall exceeding 5 mm within a 24-h period.…”