Research

Wheat curl mite-transmitted wheat streak mosaic and Triticum mosaic viruses

The wheat curl mite (WCM, Aceria tosichella, Keifer) is an eriophyid mite species complex of at least 29 different genetic lineages. Of which, Type 1 and Type 2 are economically significant as pests of bread wheat in Australia, Europe, North America, South America, and the Middle East, especially because of their ability to transmit a range of phytopathogenic viruses, known as mite vectored virus diseases or MVVDs. Wheat streak mosaic virus (WSMV) and Triticum mosaic virus (TriMV) are of particular concern to dual purpose wheat production in Texas and the Great Plains. To address this dual threat, the primary goal of our inter-disciplinary team: Charles Rush, Shuyu Liu, and Jackie Rudd is to study transmission biology of WSMV & TriMV by wheat curl mites and to elucidate the impact of host resistance on pest incidence, disease epidemiology and wheat production.

Thrips-transmitted tomato spotted wilt virus

Thrips-transmitted tomato spotted wilt virus is unquestionably one of the most devastating pest-disease complexes for growers in Texas and globally. Since the first report of the ‘spotted wilt’ disease of tomato published in 1915 in Australia, tomato spotted wilt virus (TSWV) has become a pandemic virus with an estimated economic impact over $1 billion annually. Broad spectrum and durable single gene resistance to TSWV was deployed in commercial tomato (‘Sw-5b’ gene) and pepper (‘Tsw’ gene) cultivars worldwide. However, increasingly more virulent resistance breaking (RB) strains of TSWV have been reported across the globe in recent years, which have compounded TSWV risk at an unprecedented scale. To address this dual threat, the primary goal of our inter-disciplinary team: Charles Rush, Jeanmarie Verchot, and Kevin Crosby is to develop new tools, technology, and approaches for the study and management of thrips and tomato spotted wilt.

Potato psyllid-transmitted Candidatus Liberibacter solanacearum

Zebra chip (ZC) disease poses a substantial threat to the US potato industry valued at ~$4 billion. ZC is associated with the fastidious, phloem-limited bacterium Candidatus Liberibacter solanacearum (Lso), which is transmitted by the potato psyllid (Bactericera cockerelli). With the lack of cure for Lso and unavailability of resistant potato cultivars, current management strategies heavily rely on chemical control of psyllids, which is both economically and environmentally unsustainable. Since both Lso and psyllids exploit the phloem, the preferred management approach would be to develop and deliver therapeutics directly into phloem. We’re currently working with two start-ups to develop and evaluate novel products that could be potentially used for psyllid and Lso management.

Role of candidate genes in aphid virulence

The greenbug or wheat aphid (Schizaphis graminum) is an economically important pest of a range of grasses in the plant family Poaceae. The aphid infests a number of crops such as wheat, sorghum, barley and oat and transmits major viral pathogens such as barley yellow dwarf virus (BYDV) in a persistent circulative manner. Our lab is collaborating with Subhashree Subramanyam at USDA-APHIS, West Lafayette, IN to determine the role of certain candidate genes in the greenbug aphid virulence in wheat.

Raman spectroscopy in plant disease diagnostics, virus movement & transmission

Raman spectroscopy (RS), a modern analytical technique, is capable of probing structure and composition of various materials. Our lab is collaborating with two researchers at Texas A&M University, College Station:

Dmitry Kurouski to investigate the accuracy of a hand-held Raman spectrometer in confirmatory diagnostics of biotic and abiotic stresses in different crops.

Aart Verhoef to study the movement and transmission of plant viruses in insect and non-insect vectors using a custom-built Raman microscope.