Diagnostic tool for detection of Napier Stunt Disease | Protocols, Manuals and Standards (Protocols & Software)
Description of the technology or innovation
TIMP No. 51: Detection of NGS phytoplasmas Nested PCR with universal 16Sribosomal RNA primers;
TIMP No. 52: Further amplification with primers fU5/rU3 which gives ampliconof 880 bp;
TIMP No. 53: RFLP to further characterize phytoplasma group using restrictionenzymes e.g. RsaI, AluI, and HaeIII;
TIMP No. 54: Fragments separated by electrophoresis;
TIMP No. 55: Specific probes for groups 16SrIII and 16SrXI from cloned fU5/rU3PCR products;
TIMP No. 56: Non-radioactive nucleic acid hybridisation (nrNAH) detection.
Assessment/reflection on utilization, dissemination & scaling out or up approaches used
 |  |
| Figure 1: Symptoms of NapierStunt Disease | NHS-infected Napier sourceplants (Kenya) |
Current situation and future scaling up
This tool addresses the critical issue of timely detection incontrolling Napier Stunt Disease (NSD). The tool offsets losses to farmers that would arise due to NSD. The tool addresses fodder situation for whichwomen are usually responsible in households.
Economic Considerations
Increasing Napier yield, however, leads to increased feed securitywhich may enable increased dairy production. This in effect, translates into better nutrition and food security. Byreducing effect of Napier stunt disease, the tool is a valuable resourcelivestock productivity.
Contact details
Yaima Arocha;
Scientist, Rothamsted Research;
Harpenden, Herts, AL5 2JQ;
United Kingdom (UK).
Tel: +44 (0) 1582 763 133
Email: arocharosete57@googlemail.com
John Locus;
Scientist, Rothamsted Research;
Harpenden, Herts, AL5 2JQ;
United Kingdom (UK).
Tel: +44 (0) 1582 763 133 ext: 2779
Email: john.lucas@rothamsted.ac.uk
Additional information
In order to keep the disease in check, the following should bedone: (i) inspect the crop regularly; (ii) remove the diseased Napier grassstools and burn all the uprooted diseased materials; (iii) use clean plantingmaterials from disease-free areas; (iv) improve the health of the Napier grassby applying manure or fertilizer; (v) avoid harvesting from the same areafrequently; (vi) when harvesting, cut the Napier grass leaving a stubble heightof 5 to 10cm above ground level; (vii) use alternative fodder species such asgiant Panicum, Guatemala grass and fodder sorghum if the area is seriouslyaffected because most Napier varieties are susceptible to stunt disease; and(viii) sensitize neighbours about the transmission mechanisms and management ofthe disease.
§ The phytoplasma associatedwith Napier grass stunt disease in Ethiopia was molecularly characterized as amember of the subgroup 16Srill-A.
§ Potential leafhopper vectorsand alternative plant hosts were identified for the Napier grass stuntphytoplasma.
§ Ustilago kamerunensis was morphologically and molecularly identified, using ß-tubulinand ITS regions, closely related to U.trichophora and U. davisii.
§ A non-radioactive nucleicacid hybridization assay was standardized for the detection of U. kamerunensis from cultures and PCRproducts, and its optimization from detecting directly from Napier leaves is inprogress.
Glossary
Haussmann, B.I.G., Hess, D.E., Koyama, M.L., Grivet L., Rattude,H.F.W. and Geiger, H.H. 2000a. Breeding for Striga resistance in cereals.MargrafVerlag, Weikersheim, Germany.
Haussmann, B.I.G., Hess, D.E., Geiger, H.H. and Welz, H.G. 2000 b.Improved methodologies for breeding Striga-resistant sorghums. (ReviewArticle). Field Crops Research. 66, 195-201.