Sorghum is a major food staple in sub-Saharan Africa (SSA), but its production is constrained by the parasitic plant Striga that attaches to the roots of many cereals crops and causes severe stunting and loss of yield. Away from cultivated farmland, wild sorghum accessions grow as weedy plants and have shown remarkable immunity to Striga. We sought to determine the extent of the resistance to Striga in wild sorghum plants. Our screening strategy involved controlled laboratory assays of rhizotrons, where we artificially infected sorghum with Striga, as well as field experiments at three sites, where we grew sorghum with a natural Striga infestation. We tested the resistance response of seven accessions of wild sorghum of the aethiopicum, drummondii, and arundinaceum races against N13, which is a cultivated Striga resistant landrace. The susceptible control was farmer-preferred variety, Ochuti. From the laboratory experiments, we found three wild sorghum accessions (WSA-1, WSE-1, and WSA-2) that had significantly higher resistance than N13. These accessions had the lowest Striga biomass and the fewest and smallest Striga attached to them. Further microscopic and histological analysis of attached Striga haustorium showed that wild sorghum accessions hindered the ingression of Striga haustorium into the host endodermis. In one of the resistant accessions (WSE-1), host and parasite interaction led to the accumulation of large amounts of secondary metabolites that formed a dark coloration at the interphase. Field experiments confirmed the laboratory screening experiments in that these same accessions were found to have resistance against Striga. In the field, wild sorghum had low Area under the Striga Number Progressive curve (AUSNPC), which measures emergence of Striga from a host over time. We concluded that wild sorghum accessions are an important reservoir for Striga resistance that could be used to expand the genetic basis of cultivated sorghum for resistance to the parasite.

Protected areas occupy about 27% of Tanzania’s land of 945,000 sq km and contribute 17.5% of its GDP. But who benefits from and pays for the cost of conservation? This study provides insights into these issues based on a survey conducted in the Serengeti ecosystem, involving 20 villages in Serengeti and Loliondo. The results show that villagers received insignificant benefits from conservation compared with the costs they are incurring. Governance of income at the village level was also a major challenge. There was a lack of capacity to handle large amounts of money and little or no planning, transparency, and accountability. It is recommended that income allocation to the communities is increased and external audits of village funds are conducted. Communities should furthermore be allowed to extract resources sustainably in protected areas. Youth should be encouraged to attend higher education and wildlife technical colleges to learn about the values of wildlife. Finally, the governance structures must be improved to make them gender equitable, participatory, transparent, and fully accountable to the communities and all citizens.

The parasitic weed Striga hermonthica hampers the production of sorghum, the most important cereal crop in Eritrea. This weed has a complex mode of infestation that adapts to many hosts and environments, complicating conventional breeding for resistance, which is the only form of crop improvement available to Eritrean breeders, but has failed. This study aimed at improving resistance against this parasite by transferring 5 Striga resistant Quantitative Trait Loci (QTLs) from resistance donor N13 to Striga susceptible Farmer-Preferred Sorghum Variety (FPSV) Hugurtay from Eritrea. The method involved backcrossing using marker-assisted selection (MAS) and evaluation of the best introgressed lines for Striga resistance in artificially infested fields. Foreground selection was performed with up to 11 polymorphic simple sequence repeat (SSR) markers linked to Striga resistance QTLs, while background selection was conducted in the BC 3 F 2 generation with 27 polymorphic unlinked SSR markers to identify the best recovery of the recurrent parent (RP) genetic background. Out of 84 BC 3 F 3 lines, L2P3-B, L1P5-A and L2P5P35 performed best with respect to both grain yield and reduced Striga infestation. These lines were more resistant to Striga than Hugurtay, but less resistant than N13. The three lines yielded twice as much as N13, with Area Under Striga Number Progression Curve (AUSNPC) values on average 18% higher than that of N13 and 38% lower than that of Hugurtay. This suggests that the introgressed QTLs conferred significant Striga resistance and yield advantage to these BC 3 F 3 backcross progenies under Striga pressure. These lines have good potential for future release and demonstrate that when MAS is available to conventional breeders, even in countries with no genotyping facilities, it is a useful tool for enhancement, expediency and precision in crop improvement.

Background Since their domestication 10,500 years ago, goat populations with distinctive genetic backgrounds have adapted to a broad variety of environments and breeding conditions. The VarGoats project is an international 1000-genome resequencing program designed to understand the consequences of domestication and breeding on the genetic diversity of domestic goats and to elucidate how speciation and hybridization have modeled the genomes of a set of species representative of the genus Capra. Findings A dataset comprising 652 sequenced goats and 507 public goat sequences, including 35 animals representing eight wild species, has been collected worldwide. We identified 74,274,427 single nucleotide polymorphisms (SNPs) and 13,607,850 insertion-deletions (InDels) by aligning these sequences to the latest version of the goat reference genome (ARS1). A Neighbor-joining tree based on Reynolds genetic distances showed that goats from Africa, Asia and Europe tend to group into independent clusters. Because goat breeds from Oceania and Caribbean (Creole) all derive from imported animals, they are distributed along the tree according to their ancestral geographic origin. Conclusions We report on an unprecedented international effort to characterize the genome-wide diversity of domestic goats. This large range of sequenced individuals represents a unique opportunity to ascertain how the demographic and selection processes associated with post-domestication history have shaped the diversity of this species. Data generated for the project will also be extremely useful to identify deleterious mutations and polymorphisms with causal effects on complex traits, and thus will contribute to new knowledge that could be used in genomic prediction and genome-wide association studies.