Using Lens lamottei to transfer anthracnose resistance to lentil varieties

Non-Peer ReviewedAnthracnose is a serious fungal disease of lentil that can cause severe yield loss. It is now widespread in Saskatchewan and can be devastating in years with warm wet weather. Producers are limited to controlling this disease by crop rotation, foliar spray or development of varieties with resistance to anthracnose. Pathology research shows that we have two major strains of lentil anthracnose. Varieties like CDC Robin have resistance to one of the strains, but after exhaustive screening of cultivated lentil germplasm, no resistance was found to the second strain of anthracnose. One of the newly discovered wild species of lentil, Lens lamottei, has recently been discovered to have resistance to a combination of both strains of anthracnose when grown under field conditions in an inoculated disease nursery. The objective of this project is to determine if L. lamottei can be by crossed with L. culinaris in order to transfer anthracnose resistance into lentil varieties

RAPD and AFLP markers linked to anthracnose resistance gene in PI 320937 lentil (Lens culinaris Medik.)

Non-Peer ReviewedColletotrichum truncatum (Schwein.) Andrus & W.D. Moore is the causal fungus for anthracnose disease in lentils. A germplasm accession, ‘PI 320937’, is among the lines used as a resistance source to develop cultivars in the breeding program. A cross of Eston (susceptible) and PI 320937 (resistant) was used to develop 147 recombinant inbred lines (RILs) to study the genetics of resistance and identify markers associated to the resistance gene. The F5:6 RILs were inoculated with C. truncatum isolate 95B36 at 105 conidia ml-1 and scored for anthracnose reactions over 2 replications in the greenhouse. About 600 RAPD and 10 AFLP primers were screened. We used bulk segregant analysis to construct contrasting DNA bulks, one containing only resistant and the other only susceptible plants based on the greenhouse tests. These polymorphic markers between parental lines were used to genotype RILs and make linkage analysis. Segregation data indicated that a single major gene (LCt-2) confers resistance. Minor genes also modified the level of resistance. Two RAPD markers; namely, OPE O61250 and UBC 704700 were linked in repulsion and coupling at 6.4 and 10.8 cM, respectively, to the resistance gene. Also, 3 AFLP markers were identified within 30 cM distance from the resistance locus. These markers will be useful in lentil breeding via marker-assisted selection towards developing cultivars with anthracnose resistance

Efficacy of Aquatain, a Monomolecular Film, for the Control of Malaria Vectors in Rice Paddies

Background Rice paddies harbour a large variety of organisms including larvae of malaria mosquitoes. These paddies are challenging for mosquito control because their large size, slurry and vegetation make it difficult to effectively apply a control agent. Aquatain, a monomolecular surface film, can be considered a suitable mosquito control agent for such breeding habitats due to its physical properties. The properties allow Aquatain to self-spread over a water surface and affect multiple stages of the mosquito life cycle. Methodology/Principal Findings A trial based on a pre-test/post-test control group design evaluated the potential of Aquatain as a mosquito control agent at Ahero rice irrigation scheme in Kenya. After Aquatain application at a dose of 2 ml/m2 on rice paddies, early stage anopheline larvae were reduced by 36%, and late stage anopheline larvae by 16%. However, even at a lower dose of 1 ml/m2 there was a 93.2% reduction in emergence of anopheline adults and 69.5% reduction in emergence of culicine adults. No pupation was observed in treated buckets that were part of a field bio-assay carried out parallel to the trial. Aquatain application saved nearly 1.7 L of water in six days from a water surface of 0.2 m2 under field conditions. Aquatain had no negative effect on rice plants as well as on a variety of non-target organisms, except backswimmers. Conclusions/Significance We demonstrated that Aquatain is an effective agent for the control of anopheline and culicine mosquitoes in irrigated rice paddies. The agent reduced densities of aquatic larval stages and, more importantly, strongly impacted the emergence of adult mosquitoes. Aquatain also reduced water loss due to evaporation. No negative impacts were found on either abundance of non-target organisms, or growth and development of rice plants. Aquatain, therefore, appears a suitable mosquito control tool for use in rice agro-ecosystems

Factors affecting fungus-induced larval mortality in Anopheles gambiae and Anopheles stephensi

<p>Abstract</p> <p>Background</p> <p>Entomopathogenic fungi have shown great potential for the control of adult malaria vectors. However, their ability to control aquatic stages of anopheline vectors remains largely unexplored. Therefore, how larval characteristics (<it>Anopheles </it>species, age and larval density), fungus (species and concentration) and environmental effects (exposure duration and food availability) influence larval mortality caused by fungus, was studied.</p> <p>Methods</p> <p>Laboratory bioassays were performed on the larval stages of <it>Anopheles gambiae </it>and <it>Anopheles stephensi </it>with spores of two fungus species, <it>Metarhizium anisopliae </it>and <it>Beauveria bassiana</it>. For various larval and fungal characteristics and environmental effects the time to death was determined and survival curves established. These curves were compared by Kaplan Meier and Cox regression analyses.</p> <p>Results</p> <p><it>Beauveria bassiana </it>and <it>Metarhizium anisopliae </it>caused high mortality of <it>An. gambiae </it>and <it>An. stephensi </it>larvae. However, <it>Beauveria bassiana </it>was less effective (Hazard ratio (HR) <1) compared to <it>Metarhizium anisopliae. Anopheles stephensi </it>and <it>An. gambiae </it>were equally susceptible to each fungus. Older larvae were less likely to die than young larvae (HR < 1). The effect of increase in fungus concentration on larval mortality was influenced by spore clumping. One day exposure to fungal spores was found to be equally effective as seven days exposure. In different exposure time treatments 0 - 4.9% of the total larvae, exposed to fungus, showed infection at either the pupal or adult stage. Mortality rate increased with increasing larval density and amount of available food.</p> <p>Conclusions</p> <p>This study shows that both fungus species have potential to kill mosquitoes in the larval stage, and that mortality rate depends on fungus species itself, larval stage targeted, larval density and amount of nutrients available to the larvae. Increasing the concentration of fungal spores or reducing the exposure time to spores did not show a proportional increase and decrease in mortality rate, respectively, because the spores clumped together. As a result spores did not provide uniform coverage over space and time. It is, therefore, necessary to develop a formulation that allows the spores to spread over the water surface. Apart from formulation appropriate delivery methods are also necessary to avoid exposing non-target organisms to fungus.</p

Symbolic Representation of Nature and Women in Oromo Oral Narratives

The main objective of this study was to explore the link between the symbolization of nature and women in Oromo oral narratives. Its emphasis was on deciphering conceptual associations made between the two entities focusing on metaphors, motifs and discourses. To this end, folk-narratives were gathered from four different zones of Oromia national regional state through fieldwork. Besides, published oral narrative collections of the region are used as secondary data

Genetic study of Ascochyta blight resistance in chickpea and lentil

Non-Peer ReviewedAscochyta blight is responsible for severe crop losses in most chickpea and lentil production areas around the world. The research was conducted to study the genetic basis for Ascochyta blight resistance in chickpea and lentil by means of QTL analysis, and PCR-based approaches to identify resistance gene analogues (RGA) sequences in the lentil genome. An AFLP and three SSR markers were linked to the gene(s) for Ascochyta resistance in a chickpea population derived from a cross between CDC Chico and CDC Marengo. Two QTL that explained 36 % and 29 % of the disease reaction variability were identified in a lentil RI population derived from a cross between ILL5588 and L692-16-1. These markers were converted into SCAR markers to simplify their use for marker-assisted selection

Platelet and blood transfusion in a child with dyskeratosis congenita for dental extraction – a case report

Introduction and Objective: Dyskeratosis congenita (DC) also known as Zinsser-Engman- Cole Syndrome is a rare inherited disorder with a prevalence of less than one per million. Zinsser et al. described an inherited variant of ectodermal dysplasia that affected skin, nails and mucous membranes in early 1900s.The syndrome eventually came to be known as DC and is classified as one of the inherited bone marrow failure syndromes (IBMFS). DC is the association of three clinical features: dystrophic nails, oral leukoplakia (white spots on the tongue and oral mucosa) and abnormal skin pigmentation. Case report and Conclusion: This case report describes a dental management of a case of DC. Fluctuating vital and blood parameters and deteriorating overall health status were major challenges delivering dental treatment. Dental extractions of this patient were done while maintaining blood parameters by blood and platelet transfusion.Introduction and Objective: Dyskeratosis congenita (DC) also known as Zinsser-Engman- Cole Syndrome is a rare inherited disorder with a prevalence of less than one per million. Zinsser et al. described an inherited variant of ectodermal dysplasia that affected skin, nails and mucous membranes in early 1900s.The syndrome eventually came to be known as DC and is classified as one of the inherited bone marrow failure syndromes (IBMFS). DC is the association of three clinical features: dystrophic nails, oral leukoplakia (white spots on the tongue and oral mucosa) and abnormal skin pigmentation. Case report and Conclusion: This case report describes a dental management of a case of DC. Fluctuating vital and blood parameters and deteriorating overall health status were major challenges delivering dental treatment. Dental extractions of this patient were done while maintaining blood parameters by blood and platelet transfusion

Genetic improvement of chickpea for western Canada

Non-Peer ReviewedThe chickpea crop has experienced a roller-coaster ride over the past decade in western Canada. Production rose rapidly in the late 1990’s, followed by dramatic declines in the past two years. Instability can be attributed to many factors including commodity prices, erratic weather patterns, Ascochyta blight and late maturity. This paper summarizes current research on genetic improvement of chickpea at the University of Saskatchewan, with particular emphasis on efforts to improve Ascochyta blight resistance and to develop varieties with earlier maturity. Under ‘average’ weather conditions, chickpea remains an excellent nitrogen-fixing crop for the Brown and Dark Brown soil zones

Revisiting strategies for breeding anthracnose resistance in lentil: the case with wild species

Non-Peer ReviewedBreeders at the Crop Development Centre (CDC) have up to now only used germplasm resources available in the cultivated lentil to develop new varieties with resistance to diseases. Based on recent studies, the available cultivated germplasm does not offer sufficient genetic variation for resistance to anthracnose and ascochyta diseases. Lentil crop is attacked by two major diseases (anthracnose and ascochyta) that can cause 100% loss in the worst scenarios. Since anthracnose is only a major lentil disease in North America, no work has been done to improve resistance to this disease elsewhere. Wild species of many crops are known to carry many disease resistance genes lacking in the cultivated crop. We began the search for anthracnose resistance in the six wild species of lentil (world collection), of which two can be easily crossed with the cultivated type. Two strains of anthracnose (race 1 and race 2) with varying degrees of virulence were reported. The 2002 field data suggested that some of the Lens ervoides and Lens lamottei accessions exhibited no lesions at all when exposed to the combination of the two anthracnose strains. The cultivated types that show resistance to the less virulent strain were severely affected by anthracnose. In the greenhouse study the wild species were inoculated with the two strains separately and results indicate that no accession is immune to the more virulent type. However, some of the L. ervoides and L. lamottei accessions had good resistance compared to their cultivated counterparts. As a long term strategy, the lentil breeding program at CDC, University of Saskatchewan has a goal of fully utilizing the available resistance sources. However, these two species cannot be easily crossed with the cultivated types using the conventional/manual crossing techniques. A tissue culture procedure involving embryo rescue is used to facilitate crossing. We have been able to successfully rescue some embryos from crosses with Lens ervoides. The hybrid plants produce some fertile seeds which will be evaluated for resistance to both anthracnose and ascochyta. The selected resistant lines will then be backcrossed to the adopted backgrounds in order to deploy resistance genes