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Resistance genes retain a vital role in the face of climate change
Resistance genes retain a vital role in the face of climate change
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   IMPACT OF HUMAN ACTIVITIES ON ENVIRONMENT IMPACT OF HUMAN ACTIVITIES ON ENVIRONMENT
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Resistance genes retain a vital role in the face of climate change

  1. Resistance genes retain a vital role in the face of climate change Genes giving resistance to aphid attack will still bolster the protection of groundnut varieties even if climate change brings increased drought stress. An ICRISAT study shows that drought-stressed groundnut plants or low phosphorus (P) conditions do not systematically lead to rapid increases in the population of Aphis craccivora Koch, which is the common aphid transmitting the groundnut rosette disease (GRD) that can have a significant effect on production and yield of groundnut crops. Sustainable crop production in sub-Saharan Africa is constrained by the limited availability of water, low soil fertility and by crop losses to insect pests and diseases. The advent of climate change means that drought, high temperature and low P continue to be major concerns for groundnut production in the Sahel region. An increase in the drought associated with climate change could increase the frequency and severity of insect population outbreaks, and thus, the occurrence of disease epidemics. To obtain an understanding of the combined effects of drought and low P on aphid dynamics on groundnut, and to strengthen control strategies for GRD and reduce losses to small-scale farmers, the study investigated the effects of water and P stress on A. craccivora development on four groundnut varieties. In addition to the negative effects of water stress on plant growth, drought stress increased plant nitrogen and potassium content, while low P stress reduced plant P and nitrogen contents. Aphids feed exclusively on phloem sap, and their association with plants is believed to depend on the quality of the sap. The independent effects of water and P deficits were not the same on the four groundnut varieties, suggesting that groundnut genetic background outweighed the growth conditions of the plants. Water stress had an unfavorable effect on A. craccivora development on the aphid-resistant groundnut variety ICGV 12991, while aphids performed better on the aphid-sensitive varieties Fleur 11 and 55-437 under combined drought stress and low P conditions. Such findings suggest that drought-stressed groundnut plants or low P conditions do not systematically lead to rapid increases in the A. craccivora population. In other words, genes of resistance to aphids are still needed regardless of changing growing conditions.
  2. Number progenies produced Fleur 11 ICG 11088 ICGV 12991 55-437 50454035302520151050 Well watered Water stressed Well watered Water stressed Number progenies produced Fleur 11 ICG 11088 ICGV 12991 55-437 50454035302520151050 High P Low P Figure 5. Number of aphid progenies produced on different groundnut varieties subjected to water stress Figure 6. Number of aphid progenies produced on different groundnut varieties subjected to phosphorus fertilization 25 ICRISATWestandCentralAfrica | 2015Highlights | Future-proofscienceforupcominggenerations
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