Participatory Variety Selection for enhanced promotion and adoption of improved finger millet varieties: A case for Singida and Iramba Districts in Central Tanzania

Participatory variety selection (PVS) is an approach which provides a wide choice of varieties to farmers to evaluate in their own environment using their own resources for increasing production. It enhances farmer’s access to diverse crop varieties, increases production and ensures food security and helps faster dissemination and adoption of pre and released varieties. It allows varietal selection in targeted areas at cost-effective and timely manner and helps promotion of community seed production and community seed banks. Therefore, a variety developed through PVS usually meets demand of different stakeholders. Farmers in Singida and Iramba districts in central Tanzania were found to be growing land races which were low yielding, long maturing, drought and disease susceptible, as no variety had previously been released in Tanzania. Through PVS a broader choice of varieties that matched farmer needs in adaptation and quality traits was offered for evaluation. As such PVS was used to introduce, evaluate, release and promote for adoption finger millet varieties in Central and Northern Tanzania. Farmers selected and adopted new varieties of a higher utility (a combination of improved agronomic traits, higher yield, and improved quality). Through PVS Tanzania released her first finger millet varieties (U15 and P224). Adoption of the varieties was very high as farmers associated with the varieties; and affordable high quality seed was made available as Quality Declared Seed (QDS) produced by the target farmer groups. Preferred traits differed between the gender groups; women preferred risk averting traits like short duration, drought tolerance, compact heads and disease resistance while male preferred market related traits (high yield, brown colour and big head

Genotyping-by-sequencing-based genetic analysis of African rice cultivars and association mapping of blast resistance genes against Magnaporthe oryzae populations in Africa

Understanding the genetic diversity of rice germplasm is important for the sustainable use of genetic materials in rice breeding and production. Africa is rich in rice genetic resources that can be utilized to boost rice productivity on the continent. A major constraint to rice production in Africa is rice blast, caused by the hemibiotrophic fungal pathogen Magnaporthe oryzae. In this report, we present the results of a genotyping-by-sequencing (GBS)-based diversity analysis of 190 African rice cultivars and an association mapping of blast resistance (R) genes and quantitative trait loci (QTLs). The 190 African cultivars were clustered into three groups based on the 184K single nucleotide polymorphisms generated by GBS. We inoculated the rice cultivars with six African M. oryzae isolates. Association mapping identified 25 genomic regions associated with blast resistance (RABRs) in the rice genome. Moreover, PCR analysis indicated that RABR_23 is associated with the Pi-ta gene on chromosome 12. Our study demonstrates that the combination of GBS-based genetic diversity population analysis and association mapping is effective in identifying rice blast R genes/QTLs that contribute to resistance against African populations of M. oryzae. The identified markers linked to the RABRs and 14 highly resistant cultivars in this study will be useful for rice breeding in Africa

Integrated strategies for durable rice blast resistance in sub-Saharan Africa

Rice is a key food security crop in Africa. The importance of rice has led to increasing country-specific, regional, and multinational efforts to develop germplasm and policy initiatives to boost production for a more food-secure continent. Currently, this critically important cereal crop is predominantly cultivated by small-scale farmers under suboptimal conditions in most parts of sub-Saharan Africa (SSA). Rice blast disease, caused by the fungus Magnaporthe oryzae, represents one of the major biotic constraints to rice production under small-scale farming systems of Africa, and developing durable disease resistance is therefore of critical importance. In this review, we provide an overview of the major advances by a multinational collaborative research effort to enhance sustainable rice production across SSA and how it is affected by advances in regional policy. As part of the multinational effort, we highlight the importance of joint international partnerships in tackling multiple crop production constraints through integrated research and outreach programs. More specifically, we highlight recent progress in establishing international networks for rice blast disease surveillance, farmer engagement, monitoring pathogen virulence spectra, and the establishment of regionally based blast resistance breeding programs. To develop blastresistant, high yielding rice varieties for Africa, we have established a breeding pipeline that utilizes real-Time data of pathogen diversity and virulence spectra, to identify major and minor blast resistance genes for introgression into locally adapted rice cultivars. In addition, the project has developed a package to support sustainable rice production through regular stakeholder engagement, training of agricultural extension officers, and establishment of plant clinics