While Africa is home to three Berberis species (B. holstii, B. hispanica and B. vulgaris), genera of the family Berberidaceae do not occur naturally in South Africa. However, due to the trade in ornamental plants, a total of 11 Berberis species, 11 cultivars and 8 hybrids were historically and/or are currently cultivated in the country. The current invasive status of most of these species is unknown, but two naturalized Berberis populations were recently discovered. B. julianae was found in the Golden Gate Highlands National Park in eastern Free State province, and B. aristata was found in the Woodbush Forest Reserve in Limpopo province. Since several Berberis species could act as alternate hosts for Puccinia graminis and P. striiformis, a phylogenetic study was conducted to identify both naturalized species, as well as several cultivated specimens. One of the cultivated specimens was identified as B. vulgaris, a species well known for its susceptibility to P. graminis. Knowledge gained from this study will be used to intensify the search for more naturalized Berberis populations, as well as to assess the potential threat to wheat cultivation in the country.
Displaying 11 - 14 of 14
Wheat farmers in Tajikistan measure their success by harvesting higher grain yields. However, crop yields remain very low, and losses from pests and diseases are significant. In this regard, continuous monitoring and surveillance of crops for pests and diseases and identification of resistant varieties are important. During 2011 to 2014 FAO and CIMMYT provided support for crop surveillance to obtain an overview of the most severe diseases, insects, weeds and other constraints affecting cereal crop production. Leading Tajik wheat varieties were screened for resistance to major diseases under controlled conditions in Turkey. The outcomes of the surveys demonstrated that the most devastating leaf diseases of wheat in Tajikistan are yellow rust, leaf rust and occasionally stem rust. Yellow rust was present during spike formation and flowering in most wheat growing areas. Leaf rust developed later in the season and did not significantly affect yield. In 2013 yellow rust reached epidemic levels, especially in central and central-eastern parts of the country. Stem rust was occasionally observed at moderate levels in highland spring wheat areas (above 1,000 masl). Only three varieties screened in Turkey showed resistance to yellow rust; these included Ormon and Alex that originated from CIMMYT materials. However, the majority of currently grown varieties were susceptible. Seventeen of 43 varieties were resistant or displayed only trace levels of leaf rust. Wheat crops are also damaged by powdery mildew, tan spot, Septoria leaf blotch and seed-borne diseases such as common bunt and loose smut.
Recurrent outbreaks of rusts debilitated mega wheat varieties in major production areas in Ethiopia. Projects to accelerate seed multiplication of rust resistant varieties funded by USAID, BMGF and others contributed to the replacement of the widely grown susceptible varieties Kubsa and Galama. In 2013/14, a new Pgt race (TKTTF) - unrelated to Ug99 - caused 100% yield losses on bread wheat variety Digalu. The continuing epidemic calls for fast replacement of the now susceptible varieties by accelerated seed multiplication to scale-up new varieties with durable rust resistance, and demonstrations to promote their adoption. In 2014, CIMMYT initiated a short term R4D project ‘Emergency Seed Support and Demonstration of Rust Resistant Wheat Varieties in Stem Rust Affected Areas of Ethiopia’. The project was financed by USAID and implemented in collaboration with EIAR, regional agricultural research institutes, and the Oromia Bureau of Agriculture. In collaboration with DRRW, CDL, and WSU, technical assistance was given to research centers to phenotype and genotype their breeding lines and commercial cultivars. A total of 352 Development Agents (15% female) were trained in rust identification, seed technology and crop management. Eight rust resistant varieties were demonstrated on 430 model farms in 16 districts in Oromia, Amhara and SNNPR. Awareness was created through field days organized by the Kulumsa and Sinana research centers in Arsi and Bale, respectively. Technical and financial support was given to four federal (Kulumsa, Werer, Debre Zeit, and Holetta) and three regional (Mekele, Sinana, and Adet) research centers for early generation seed multiplication. A total of 2,000 resource-poor farm households (10% female headed) selected on the basis of having suffered heavy losses to stem rust in the previous season, received technical assistance and 165 tonnes of seed of rust resistant varieties. Assisted farmers recorded above average zonal yields in 2014/15.
In recent years Pgt race Ug99 has moved out of East Africa posing a threat to other regions in Africa, Central and West Asia, and other regions where this pathotype had not been found. In Europe a new Pst population (Warrior and Kranich races) replaced less diverse pathogen populations during the years 2011-2014. To enable the tracking and monitoring of the evolution of pathogen populations, a new web/database management and display system called the Wheat Rust Toolbox was developed. This platform, hosted by the Global Rust Reference Centre, supports two major initiatives: 1) the Durable Rust Resistance in Wheat project (DRRW), for managing and visualizing wheat rust pathogen data - mainly related to the stem rust pathogen (Pgt) from Africa, Central and West Asia; and 2) the ENDURE wheat rust network for managing and visualizing stripe rust, including Pst race, virulence and genotype data for Europe. The presentation will provide an overview of data and tools available in the Wheat Rust Toolbox, the research infrastructure behind it, and how data are disseminated via several information platforms such as wheatrust.org, eurowheat.org and http://rusttracker.cimmyt.org/. Opportunities available for analyzing genotypic data (SSR and SNP) online via a web-based version of the POPPR integrated with the Wheat Rust Toolbox will be presented. Overall the results show that the collation of data in a standardized way across many countries leads to more robust and fast conclusions that will stimulate closer collaborations between partners.