Jatropha curcas L. is a biofuel-crop with several advantages. It requires minimal inputs, stabilizes or even reverses desertification and is used for a variety of products after the bio-fuel has been extracted. In addition, it can be grown on land that is normally considered unsuitable for agriculture and so does not have the same potential as the other bio-fuel crops to cause food-price inflation.
Jatropha crop in India, © 2009 University of Greenwich
NRI has a considerable pool of crop protection expertise, developed through work on jatropha's 'sister' crop cassava. We have more than 20 years experience of working on its pests and diseases, as well as on conventional resistance-breeding for plant-virus disease problems.
Contrary to popular belief, jatropha is similar to cassava in that it is susceptible to a wide range of insect pests and plant diseases. Plant viruses similar to those that infect cassava also infect jatropha. A recent survey in Karnataka State, India, showed that the occurrence of Jatropha Mosaic Virus Disease (JMVD) ranged between 13 - 47%, causing significant yield loss. Jatropha Mosaic Virus (JMV) is transmitted by the whitefly, Bemisia tabaci and there are other close similarities between this pathosystem and that of cassava mosaic virus.
Jatropha is also susceptible to a range of insect pests, notably the whitefly, B. tabaci, the leaf and capsule borer Pampelia morosalis and the Scutellarid bugs, Scutellera nobilis and Chrysocoris Purpureus. Sustainable and ecologically acceptable means of control of these pests and diseases are of paramount importance, if large scale jatropha plantations to be developed successfully in under-utilised, semi-arid regions.
At NRI, we have begun research on the JMVD pathosystem and are screening jatropha genotypes to identify those that may have JMV resistance. This conventional approach, however, faces many challenges, not least being the length of time involved for resistance gene discovery and the possibility that resistance genes may not be present in the jatropha germplasm. We are therefore also interested in the complementary approach of genetic engineering, which offers the possibility of many novel solutions but, amongst other things, requires knowledge of virus-gene functions, the infection process, the virus life-cycle and key interactions. It potentially enables the efficient disruption of these processes and therefore provides an additional opportunity to develop effective strategies for durable JMV resistance.