GROUNDNUT ROSETTE DISEASE PDF
Groundnut rosette disease (GRD), caused by a complex of three agents: groundnut rosette assistor luteovirus, groundnut rosette umbravirus. It depends on groundnut rosette assistor virus (GRAV; Luteoviridae) for encapsidation in GRAV coat protein and for transmission by Aphis craccivora in the. SUMMARY: Groundnut rosette disease is the most important disease of groundnuts of sub-. Saharan Africa. Epidemics occur without warning. It is caused by a.
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It is spread by aphids feeding on the crop.
Groundnut Rosette Disease
ICRISAT scientists continued to develop high-yielding, long-duration groundnut varieties with resistance to rosette suitable to medium and high rainfall areas. Components of integrated management of rosette using high-yielding rosette-resistant varieties ICGV-SM and ICG and cultural practices such as early sowing at optimum plant densities have been investigated. InICRISAT-Lilongwe launched a program on screening of global germplasm for resistance against rosette in order to diversify the genetic base of rosette resistance.
The chlorotic and green types are caused by two variants of the satellite RNA while the mosaic type is caused by infection with a mixture of both variants.
MANAGEMENT OF GROUNDNUT ROSETTE: PAST, PRESENT, AND FUTURE
Plants affected when young may produce no nuts. Yellow Rosette Virus, no yield will come from the infected plant right.
For example, the rosette epidemic in in central Malawi and eastern Zambia destroyed the crop to such an extent that the total area of groundnut grown in Malawi fell from 92, ha in to 65, ha in The groundnut aphid, Aphis craccivorais the principal vector of the disease.
Virus resistant varieties of groundnut have been discovered but mostly have a fisease growing period five to six months rather than three to four for other varieties and may therefore be more susceptible to drought.
Groundnut rosette virus EoL: On-farm verification and demonstration of agronomically and commercially acceptable high-yielding, rosette-resistant medium- to short-duration groundnut varieties and the package of options for integrated management of groundnut rosette needs to be intensified in the region.
There is no control for the virus once a plant is infected but control of the aphids will prevent further spread. A breeding programme has been established in Malawi focussing on disease resistance, early maturity and high yield.
Knowledge Bank home Change location. Recently, several high-yielding short-duration days Spanish types with resistance to rosette have been developed and are in on-farm evaluation in southern and eastern Africa. Views Read Edit View history. The sources of resistance from West Africa have extensively been used and several long-duration, high-yielding breeding rlsette with resistance to rosette have been developed for evaluation and utilization by the National Agricultural Research Systems in the region.
Journal of General Virology. Utilization of wider gene pools should result in identification of certain cross combinations with high recovery of disease resistance and more useful recombinants.
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Hence, there is a need to understand the factors that influence rosette disease outbreaks such as off-season survival of rosette viruses, the relative importance of primary disezse secondary spread, feeding behavior and transmission efficiency of vector, influence of climatic conditions on vector build-up and dispersal.
Mechanisms of resistance operating against individual causal agents of the disease complex and the vector need to be understood.
If you would like to, you can learn more about the cookies we use. Research has shown that plants infected by groundnut rosette virus alone show little or no effect, but that the symptoms of the disease are caused by a satellite RNA co-infectiona subviral agent.
Rosette is the most destructive disease of groundnut in Africa. Retrieved 13 February This will also be useful in establishing the allelic relationships.
In spite of several achievements made in the past, development of short-duration groundnut varieties with resistance to rosette remained as a challenge to ICRISAT for a long time. Several of these varieties had excellent performance in farmer participatory on-farm verification in Malawi, Zambia, Mozambique, and Uganda. Sources of resistance to rosette were first discovered in Senegal in This is to ensure that we give you the best experience possible.
This page was last edited on 22 Marchat In a study in Tanzania, the first affected plants were seen six days after the first aphids were observed. Plants that are infected early will produce no yield.
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Groundnut plants affected take on a bushy appearance due to stunting and distortion of the growing shoots.