Introgression of antioxidant activity into cassava (Manihot esculenta C.): an effective technique for extending fresh storage roots shelf life

Physiological postharvest deterioration (PPD) of cassava is the main constraint affecting its nutritional and economical values. PPD is induced by wounds when detaching storage roots from mother plant during harvesting. It is accelerated by the reactive oxygen species (ROS) such as oxygen ion (O₂) and peroxide (O₂)^?2. The carotenoid content and its antioxidant property can help in extending shelf life of cassava storage roots. The primary mode of action of carotenoids as antioxidant is to quench singlet oxygen. Cassava breeding was reported to successfully introgress and improve carotenoid content into cassava. The two types of phytoene synthase (PSY) enzymes (PSY1 and PSY2) are key regulators of carotenoids accumulation in cassava. Carotenoids formation and accumulation in cassava storage roots are induced by a single nucleotide polymorphism in PSY2 which causes a non‐conservative amino acid exchange. This single nucleotide polymorphism in PSY gene is co‐segregated with β‐carotene in cassava storage roots, a phenomenon that could help to unravel the mechanism of introgression of carotenoids into cassava. This article investigates breeding feasibility for improving quality of cassava landraces in developing countries.     

Assessing tolerance to soybean rust in selected genotypes

Breeding for tolerance to soybean rust is potentially one of the solutions to combating soybean rust; however, very little progress in tolerance breeding has been documented. Fourteen pre-selected genotypes were evaluated in a sprayed versus unsprayed split-plot trial conducted over three seasons for their tolerance to soybean rust. Different assessments of tolerance were compared for their effectiveness in discriminating between genotypes. Conventional methodology using a yield loss % index for assessing tolerance produced results which were poorly correlated with each other over seasons, which likely accounts for the historic lack of breeding success. This study has used the superiority measure (P_i) of Lin and Binns and the ecovalence statistic (W_i) of Wricke in a biplot to identify the most tolerant genotypes. A novel statistic (W_iP_i) has been generated from this biplot which facilitates the simultaneous selection for general performance and yield stability of genotypes under a range of rust stress conditions.     

A statewide,cross-sectional evaluation of the knowledge and level of concern of rabies among South Carolina residents

Animal rabies cases have increased steadily in South Carolina (SC) for the past decade. An understanding of the population's awareness and understanding of the disease is needed to tailor public health interventions. A marketing list-serv of SC residents' email addresses was used to recruit anonymous respondents for a Knowledge Attitudes and Practices (KAP) electronic survey. A total 516 South Carolinians completed the 31-question survey. Quantile regression and a Pearson's correlation evaluated potential associations between respondent's rabies knowledge and their attitudes and practices. Knowledge was assessed on topics of rabies biology, state animal case counts and rabies pet-related laws. Level of concern and level of knowledge were positively correlated. Additionally, statewide hotspot analysis revealed geographic areas warranting targeted public health interventions; counties with low public concern juxtapositioned with high animal rabies case counts. This study demonstrates the utility of statewide KAPs to gauge populations rabies perception and related preventative actions to tailor appropriate educational programs to limit human-animal rabies exposures.