Research Projects
Optimization of citrus propagation techniques for rapid tree production and screening for disease tolerance
Emerging biotic and abiotic challenges such as Haunglongbing, soil salinity, drought and more recently the freeze in South Texas has necessitated to derive holistic approaches for long term sustainability of citrus production. One of the key components for a healthy citrus orchard is the selection of rootstock, which is the root portion of a grafted plant. Sour Orange and C22 have been the typical rootstocks of choice for citrus production in South Texas. These rootstocks although impart vigor to the scion but have limitations. Therefore, it is important to explore novel citrus rootstocks and their hybrids that can help sustain the citrus production.
The selected intern will be working in a citrus nursery in conjunction with nursery supervisor. Training will be provided on “seed to plant” operation in a high throughput nursery. The student may also be exposed to morphometrics, data analytics and molecular techniques such as reverse-transcription polymerase chain reaction (RT-PCR).
NOTE: Applicants should be aware that working in a nursery will be challenging especially being exposed to high temperatures and humidity levels.
Detection and Diagnosis of Plant Pathogens using Modern Molecular Methods at TAMUK-Citrus Center
Diagnosis of a plant disease by checking the presence of a causal pathogen(s) in the plant tissue is the first step towards any treatment, suppression, or containment of the disease. Knowledge and expertise in using modern pathogen detection tools is a prerequisite for successful implementation of disease management strategies. Training will be provided to the students on recognition of disease symptoms such as Huanglongbing (HLB; bacterial disease) and root/crown rots caused by Phytophthora sp. (fungal) in affected citrus trees and on pre-symptomatic detection of HLB using root samples. Students will be trained in several molecular techniques including nucleic acid extraction (DNA and RNA), polymerase chain reaction (PCR), reverse-transcription PCR (RT-PCR), quantitative PCR (qPCR), and gel electrophoresis. They are expected to become proficient in detecting the aforementioned pathogens causing HLB and root/crown rot as well as other plant pathogens (e.g. virus) causing diseases in citrus using modern molecular diagnostic assays.
HLB: detection, vectors (psyllids), and pest mitigation strategies in research laboratories at TAMUK-Citrus Center.
Training will be provided to students on HLB symptoms identification and how to contrast these symptoms with other nutritional or ailment disorders. One major deliverable will be for all students to be able to scout a citrus grove or a tree and be able to independently determine HLB symptoms. Students will be trained on protein chain reaction (PCR) testing of symptomatic leaves, which will require hands-on training in DNA extraction and testing in the lab for the presence of Candidatus Liberibacter asiaticus (CLas), the bacterial pathogen causal agent of HLB.
HLB: detection, monitoring vectors (Asian citrus psyllid: ACP) and identifying symptoms of the disease in field crops.
Participants will be able to work directly with mentors and staff from TCPDMC to conduct 1) Asian citrus psyllid (ACP) scouting, 2) HLB surveys, and 3) geo-statistical analysis and comparison of new techniques to monitor ACP population sampling techniques. ACP scouting is based on trap sampling for adults and visual observation of eggs and nymphal life stages. HLB surveys include collecting symptomatic leaves and other plant tissue (e.g. lop-sided fruit) that are associated with HLB infection for additional testing.
HLB: detection, vectors (psyllids), and pest mitigation strategies in research laboratories at TAMUK-Citrus Center.
Training will be provided to students on HLB symptoms identification and how to contrast these symptoms with other nutritional or ailment disorders. One major deliverable will be for all students to be able to scout a citrus grove or a tree and be able to independently determine HLB symptoms. Students will be trained on protein chain reaction (PCR) testing of symptomatic leaves, which will require hands-on training in DNA extraction and testing in the lab for the presence of Candidatus Liberibacter asiaticus (CLas), the bacterial pathogen causal agent of HLB.
HLB: Use of drones to help survey citrus groves
The Texas citrus industry is tasked in keeping accurate records of citrus groves. An ongoing survey of existing groves is critical in accomplishing the task of the industry owners and stakeholders. The industry has a camera equipped unmanned aerial vehicle (UAV) which its intent is to help survey groves on their size, fruit type, condition and ultimate survey for diseases. A student project proposal is as follows. The student will develop a workflow on the use of UAVs that is efficient and can be easily integrated into the already existing work of the ongoing survey. This project should be focused and developed to the unique area of the Texas Citrus Industry which is the Lower Rio Grande Valley.
Mexican Fruit fly rearing, field studies and pest mitigation strategies at USDA APHIS PPQ CPHST Mission Laboratory.
Students participating in this training will learn about all aspects of insect rearing, conducting field studies, and pest mitigation strategies using the Sterile Insect Technique. Training will be provided to students on developing and conducting diet ingredient studies. Students will be trained on conducting field experiments involving release and recapture, trap placement, recapture rates, dispersal, and swathe width, and will have the opportunity to assist in field cage experiments looking at dose application rate of pheromone and resultant.
Plant virus diagnostics, biological and molecular characterization, and field epidemiology at Texas A&M AgriLife Research and Extension Center.
Training will be provided to students on recognition of virus disease symptoms relative to symptoms that mimic infection. A major deliverable will be for students to be able to identify characteristic symptoms of virus and virus-like diseases on different plant species, how to sample for accurate virus diagnosis, and determination of disease incidence. Students will also be trained on several techniques, including total nucleic acid isolation, nucleic acid quantification and quality analysis, reverse transcription polymerase chain reaction (RT-PCR) and/or PCR (depending on the nature of the virus genome), and agarose gel electrophoresis of DNA amplicons. Students will be expected to gain proficiency in these methods. In addition, students will be introduced to the development of grower outreach publications such as factsheets and popular press articles.
Research in soil ecology and nutrient cycling
This research focus on links between microbial activities and efficient nutrient cycling to identify soil management practices that sustain food production while preventing nutrient losses to the environment. The research framework will help to elucidate the resilience and resistance of soil biological processes in soils exposed to management (e.g., tillage, inputs, crop diversification) and/or climatic disturbances (e.g., drought, flooding, increasing temperatures, etc).
Cactus Moth surveys
Cactoblastis cactorum Berg, Cactus Moth, is an invasive species that could dramatically affect prickly pear species in Texas. Cactoblastis cactorum was recently recorded in Southeast Texas, which is an indication of the high risk that prickly pear in Texas are facing. Surveys for this species in the Rio Grande Valley are vital for early detection efforts and eradication. Results from this survey are equally important for New Mexico and Arizona, neighboring states of Texas. Results from this survey are also important for the neighbor country of Mexico because its cactus production could be negatively impacted from the spread of this destructive pest.
Effect of southern and northern tick epigenetic variations on gene expression
Tick-borne diseases have been gaining the attention of public health experts due to their increased incidence, especially in the northeastern and midwestern of the US where 80% of the cases occurred. What factors influence the capacity of specific tick populations to transmit pathogens remain to be defined. Epigenetics may drive biological and behavioral differences between populations of the same species as result in phenotypic plasticity. We have identified unique epigenetic variation between tick populations from Texas and Minnesota. In this project, we seek to define the effect of these epigenetic variation on gene expression. By identifying unique epigenetic drivers that influence vector capacity, we may be able to design alternative mechanism to reduce disease transmission in the US.
Development of PiroPlex and Anti-Babesia/Anti-Tick Vaccines
Development of a novel PiroPlex real time PCR diagnostic assay in veterinary medicine” and “Novel anti-tick vaccine development to control bovine babesiosis in the US-Mexico transboundary region” at TAMU and CFTRL.
Research program 1: Students will assist in the development of a multiplex qPCR (PiroPlex) test that will allow the detection, in a matter of hours, of piroplasms . Students will be testing a number of samples obtained from Texas A&M Veterinary Medical Diagnostic Laboratory, CFTRL, and Mexican collaborators.
Research program 2: Students will participate in experiments related to the development of potential anti-babesia and anti-tick vaccines. They will be involved in experiments to validate the gene expression of Babesia bovis or B. bigemina vaccine candidates when these protozoan parasites are cultivated in vitro using bovine red blood cells.
Climate Change and Variability
Students will be trained in the use of software to construct models of distribution for HLB, Mexican fruit fly, and/or CFT outbreaks in the future under climate change scenarios. Students will learn where to download current and future climatic data and free software (e.g., MaxEnt) for species distribution modeling. We expect the students to identify the potential impacts of climate change in the distribution of vector borne diseases. Students participating in climate change and variability will be co-mentored by mentors at TCPDMC, ARS USDA CFTL, USDA PPQ CPHST and UTRGV.
Research in soil ecology and nutrient cycling
This research focus on links between microbial activities and efficient nutrient cycling to identify soil management practices that sustain food production while preventing nutrient losses to the environment. The research framework will help to elucidate the resilience and resistance of soil biological processes in soils exposed to management (e.g., tillage, inputs, crop diversification) and/or climatic disturbances (e.g., drought, flooding, increasing temperatures, etc).
Cactus Moth surveys
Cactoblastis cactorum Berg, Cactus Moth, is an invasive species that could dramatically affect prickly pear species in Texas. Cactoblastis cactorum was recently recorded in Southeast Texas, which is an indication of the high risk that prickly pear in Texas are facing. Surveys for this species in the Rio Grande Valley are vital for early detection efforts and eradication. Results from this survey are equally important for New Mexico and Arizona, neighboring states of Texas. Results from this survey are also important for the neighbor country of Mexico because its cactus production could be negatively impacted from the spread of this destructive pest.
Special Crops – Native Plants Project
Use of native plants on both private and public lands in the Valley. Student participants can expect the following: training in field work (collecting and processing native seeds and conducting nursery greenhouse work with thornforest seedlings); lab-based research in seed viability and research into genetic variation among forest species. The answers to these questions will help us to expand restoration of the Valley’s threatened thornforest ecosystem and also the usage of native plants in landscaping in the coming years. They will also help us to better understand how resilient these plantings need to be in order to face long-term challenges like urbanization and climate change in the Valley. This study is conducted in collaboration with American Forest
Discovering the bioactivity of small molecules on tick receptors and tick
The cattle fever tick is a menace to the Texas cattle industry because it transmits the Babesia spp. parasites that are causative agents of cattle tick fever, a deadly cattle disease for which there is no recombinant vaccine. Disease prevention focuses on tick control, but many pesticides used to control ticks are no longer effective. Other species of ticks transmit diseases to humans. We are studying tick physiology at the molecular, tissue and whole tick level with the goal of identifying novel molecules that could disrupt tick physiology and cause tick death. We have identified small synthetic molecules and small peptides that are hypothesized to disrupt blood feeding and reproduction. The student will learn to perform several bioassays, learn mammalian cell culture and aid with physiological experiments that aim to discover the function of peptide hormones in ticks. Insects are also available to perform preliminary studies. Graduate students and post-docs will aid the student throughout the project and the student will experience the scientific process in real time in the toxicology and physiology laboratory in the Department of Entomology at TAMU. The laboratory is equipped with state-of-the-art instrumentation and is funded by several federal and state programs. The principles and techniques learned will apply to any insect or arthropod pest. The student will receive training to work in a Biosafety level 2 laboratory. Please see more about the laboratory and the professor at https://entomology.tamu.edu/people/pietrantonio-patricia/. Other projects in pests of agriculture are available in the laboratory.
Investigating the role of olfactory cues from insect honeydew in attracting natural enemies
Several species of natural enemies are known to feed on aphid honeydew and use honeydew-associated cues to help locate potential hosts. Sugar, amino acid and organic acid concentrations in honeydew may vary significantly among aphids feeding on different host plant species, affecting the preference and performance of parasitoids and aphid susceptibility to natural enemies when feeding on different plant species. Bacterial symbionts have been shown to alter honeydew nutritional quality and/or attractiveness for natural enemies in some aphid species. For example, preliminary data from our research team, shows significant differences in microbiota composition between sorghum aphid honeydew feeding on sorghum and Johnson grass. In this project we aim to characterize olfactory cues from aphid honeydew collected from insects feeding on different host plant species. Variation in honeydew volatile profiles among aphids feeding on different host plants may result from changes in honeydew bacterial communities when aphids feed on different plant species. Furthermore, honeydew olfactory cues may influence natural enemy attraction and suppression of aphid populations.
Effects of flooding and climate change on agro-ecosystems
Our team is part of a University of Texas at Austin Grand Challenge, Planet Texas 2050, that focuses on developing resilience to climate-related events that affect our health and well-being. Our specific project AIM (AI-enabled modelling) brings together expertise in computational and geospatial modelling of activities and events influenced by extreme weather that can affect agro-ecosystems including flooding, the egress of invasive species and emerging microbiota in soil and water. We are working closely with UT RGV to develop models applicable to Texas including the lower Rio Grande Valley and bordering regions, utilizing local, national and global data from a wide variety of sources.