Plant Pathology Research Areas
The Department maintains well-balanced research programs ranging from fundamental studies of host-parasite physiology to more applied studies of disease control in rice, soybean, cotton, wheat, sorghum, turf, fruits and vegetables. The Department has a strong research history in biological control of diseases and weeds, virology, fungal biology and nematology. The Department also has wide-ranging extension plant pathology programs dedicated to education of growers and the general public about managing plant health using the latest available research and offers numerous graduate level courses in plant pathology for traditional and non-traditional students.
Research Areas
Current Electron Microscopy Research:
Research using electron microscopy combined with other cyto- and immuno-chemical techniques, have made it possible to find virus-specific cytopathological inclusions of many plant virus groups. Current research directions have focused on ultrastructure and cytochemistry of normal and diseased cells elucidating subcellular responses of host plants to infections of viruses as well as other pathogens.
Current Research on Soybeans:
Current research in Arkansas has focused on the epidemiology and control of various soybean diseases with emphasis on sudden death syndrome (SDS) and stem canker. The SDS research has lead to the identification of the causal agent Fusarium solani. Current research is investigating the effects of rotation, irrigation, soil moisture, and disease development or yield. Work with stem canker involves the effect of timing of infection on disease development, environmental factors influencing disease, cultivar resistance, and use of fungicides for control.
There is limited knowledge on the viruses that infect soybean in Arkansas. Our goal is to identify the viruses present and their involvement in diseases observed in the state. Ultimately, we are looking into the development of an IPM program that will minimize chemical input and yield losses.
We are also working on a reverse genetics project using viruses as vectors for RNA interference. Our goal is to identify and characterize genes involved in disease development and resistance. In collaboration with breeders in the U of A, we aim to develop techniques that will allow us to identify genes for the improvement of the crop.
Current Research on Cotton:
Current research on cotton in Arkansas focuses on the ecology of soilborne plant pathogens. Research directions have concentrated on the influence of soil physical factors and sustainable agricultural practices (winter cover crops and conservation tillage) on soilborne pathogens, including Rhizoctonia solani, Thielaviopsis basicola, and Pythium spp. The importance of chronic disease on seedling development and yield is being investigated.
Current Research in Nematology:
Current research in Nematology has focused on the taxonomic and morphologic studies of several phytoparasitic nematodes. Recent research directions have concentrated on the virus-vectoring genera Xiphinema and Longidorus; morphological and molecular studies on the Hoplolaimidae; resistance to the reniform nematode in cotton and soybean; rotation studies of soybean cyst nematode using different resistance reactions of the soybean; and the role of phytoparasitic nematodes in conjunction with other biological entities and cultural practices
Other research conducted at the Southwest Experimental Station (Hope, AR) has focused on the biology and control of plant-parasitic nematodes of agronomic crops with an emphasis on Meloidogyne incognita in cotton and vegetables. Research directions have focused on the quantification of the effects of M. incognita on cotton plant growth, development, and yield and in developing economically feasible root-knot management strategies for cotton and vegetable producers. Research has helped draw attention to the widespread occurrence of M. incognita in Arkansas and has demonstrated the potential for significant crop yield decreases where the nematode occurs. This work along with studies of the effects of crop rotation and genetic resistance for minimizing nematode damage is producing leadership in developing feasible integrated pest management strategies for growers in the mid-South.
Current Research on Rice:
Current research on rice focuses on the epidemiology and control of many important rice diseases with an emphasis on sheath blight (Rhizoctonia solani), rice blast (Magnaporthe grisea), kernel smut (Tilletia barclayana), stem rot (Sclerotia oryzae), bacterial panicle blight, false smut and other diseases of the southern U.S. production region.
Sheath blight research has focused on discovery of germplasm with more acceptable levels of resistance; the search for marker genes for sleath blight resistance (with RiceCAP; the impact of cultural practices, and the economic use of new fungicides.
Current research on rice blast disease has emphasized diversity of the pathogen population; discovery of new resistance genes in diverse rice germplasm used in breeding for the southern U.S.; physiology of flood depth and anaerbiosis of the rhizosphere on resistance in rice; seedborne nature and transmission of rice blase disease; and fungicides.
Research on kernel smut and false smut of rice has focused on fungicides to minimize the diseases; etiology and epidemiology of false smut; reaction of southern U.S. rice germplasm to both diseases under field conditions; and effect of nitrogen fertilizer rate and timing on kernel smut.
Research on bacterial panicle blight has centered on screening of germplasm under field conditions for reaction to the pathogen and the development of PCR based detection methods for seed.
Research on stem rot is currently focused on understanding the role of potassium fertilization and soil potassium levels on severity of disease and the effect of preventative fungicide applications in control.
Current Research on Vegetable Crops:
Tomato diseases...
Spinach diseases... http://spinach.uark.edu/
Cowpea diseases...
Current Research on Fruit Diseases:
Several new diseases have emerged in blackberry and blueberry in the recent years and our research is focusing on the causal agents and their epidemiology. The ultimate scope of this research is to identify virus vectors and develop sustainable control measures for both vectors and diseases.
Current Research on Grain Sorghum:
Current research involves the population dynamics of Colletotrichum sublimeolum (leaf anthracnose of sorghum) in Arkansas and the screening germplasm of Sorghum bicolor for leaf and stalk anthracnose resistance.
Current Research on Ornamentals:
Ornamentals is a multi-billion industry around the world. Due to the clonal propagation of several ornamental crops, viruses accumulate and cause significant losses due to the alteration of the phenotype of the plants. Two ornamental diseases that persist for several years are rose rosette and redbud ringspot. We are working on the molecular characterization of the causal agents and the development of detection methods that would help to control the diseases and minimize losses in the nursery and ornamental industry.
(Top)Current Research on Wheat Diseases:
Research on Fusarium head blight involves characterizing resistance in breeding lines and cultivars, developing more effective methods for characterizing resistance, evaluating foliar fungicides for efficacy, and participating in a regional effort to develop resistant cultivars. Research on stripe rust involves characterizing adult-plant resistance in cultivars and breeding lines and characterizing the important differences between old (before 2000) and new (since 2000) strains of the pathogen. Other research involves developing lines with resistance to barley yellow dwarf, evaluating cultivars for resistance to important diseases, evaluating seed treatment and foliar fungicides or efficacy under Arkansas conditions, and determining the economic return of applying foliar fungicides to commonly-grown cultivars.
Management of Fusarium Head Scab of Wheat in Arkansas
Current Research in the Biological Control of Pests:
Biological control of weeds...
Biological control of plant pathogens...
Risk assessments of biological control agents...
Current Graduate Student Research Programs
- Morphology and taxonomy of Hoplolaimidae (Nemata: Tylenchoidea) occurring in USA.
- Morphology and taxonomy of Longidoridae (Nemata: Dorylaimida) occurring in Arkansas
- Screening for resistance to Fusarium wilt (Fusarium oxysporum f.sp. spinaciae) in spinach (Spinacea oleracea L.).
- Resistance in frost red winter wheat to leaf rust
- AFLP and DNA sequencing to characterize Colletotrichum spp.
- Isolation and characterization of rice myb genes induced by the blast fungus.
- Soybean resistance to Phompsis seed decay
- Effect of surfactants on white rust (Albugo occidentalis L.) of spinach.
- Development of rhyzobacteria for biocontrol of soybean cyst nematode.
- Characterization of viral molecular determinants of host range in southern bean mosaic virus
- Characterization of seed transmission cucumber mosaic virus in spinach (Spinacia oleracea L.) and production of transgenic plants.
- Black root rot (Thielaviopsis basicola) and Root-knot (Meloidogyne incognita) interactions on cotton.
- ffect of Soybean Cyst Nematode (SCN) Population and SCN Resistance on the Development of Sudden Death Syndrome of Soybean.
- Characterization of Races of Phytophthora sojae in Arkansas and their Effects on Commonly Grown Soybean Cultivars
- Effects of Pythium species on Soybean Growth and Development as Related to Periodic Soil Flooding.