Progress 09/21/05 to 07/09/08
Outputs
Progress Report Objectives (from AD-416) Establish distributions of red rice types in the U.S., their intercrossing rates with rice, and visual and marker classes for accurate identification of resistant hybrids. Improve the long-term sustainability of weed control with reduced inputs by discovering, developing, or improving rice germplasm that suppresses barnyardgrass with minimal herbicide application. Identify the specific growth response(s) elicited by poultry litter in rice plants and determine the chemical constituents in the litter that induce these growth responses. Measure carotenoids non-destructively in single rice grains to understand the induction of carotene synthesis in rice endosperm under stress conditions of high heat and moisture. Approach (from AD-416) Distinct populations of HR (herbicide-resistant) red rice, and rice-red rice hybrids from rice fields in the southern US can be detected, identified, and managed or exploited through genetic assessment and regional distribution of red rice ecotypes, reciprocal outcrossing between rice and red rice, and hand-crossed hybrids. Identify and/or advance rice lines that have grain quality and plant types of commercial or near-commercial acceptability so that weeds may be controlled in farmer fields at reduced herbicide rates. Investigate the growth- promoting effects of poultry litter on rice beyond nutrient augmentation alone. Study how the environmental and biological stresses influence the genetic and physiological control of the induction of carotenoid synthesis that occurs during heat-stress induced PHY (a yellow discoloration) of rice grains and adapt techniques to study molecular genetic differences in milled rice. Significant Activities that Support Special Target Populations Worldwide Oryza entries, including 46 US red rice (RR) lines, were analyzed for genetic differences using 31 SSR markers. Genetic differences between lines of major RR types increased with geographic distance, but RR shared little genetic structure with wild/cultivated red rice lines and cultivars used as standards. In other RR lines having traits (e.g., short stature) similar to those present in progeny of rice- RR hybrids, only 1/70th of the alleles identified using SSR were consistent with those in rice, suggesting that gene flow from rice to RR has been very limited. Significant chemical and starch structure differences in RR and commercial rice seeds have also been characterized. In field studies, gene flow from RR to rice was <0.8%, and was greater than in the reverse direction; differed by as much as 20X over years; was greater in April than in May plantings; and was greater in hybrid rice than non-hybrids. In other field studies, stable isotopes (15N and 13C) were used to evaluate rice-weed interactions. RR absorbed more 15N from urea fertilizer and used it more efficiently for growth than did rice, emphasizing the need to manage fertilizer properly. Rice:barnyardgrass root mass ratios (13C analysis) in weed-suppressive rice can reach 2X the levels found in non-suppressive rice, indicating that roots may be a key to effective weed suppression. Weed suppressive rice usually controlled weeds better than commercial cultivars, but performed poorly in heavy weed infestations. Weed suppression levels in crosses developed from allelopathic and commercial rice was usually no better than that in commercial rice, highlighting problems in breeding for this trait. Poultry litter (PL) has been used as a source of fertilizer and found to contain components that alter rice plant growth. Tiller number is a quantifiable growth parameter that is altered by PL with direct implications on yield. Components extracted from PL with organic solvents were found to have varying impacts on tillering. PL components are active on rice as well as other grass crops. Using GC-MS, the components appear to be steroidal in structure. These results demonstrate that the growth altering components may provide a means to increase rice yield as well as to study the mechanisms of tillering in rice. Carotenoids, antioxidant compounds commonly found in food plants, were measured in the bran of numerous rice cultivars from different genetic subpopulations using a non-destructive fluorescence spectrometer technique. Using extraction and HPLC, lutein was identified as the primary carotenoid that varied among cultivars. Numerous environmental factors affect the occurrence of straighthead, a physiological disease. A greenhouse technique for inducing straighthead that would allow for greater ability to identify critical factors that trigger straighthead symptoms has been established, and cultivars resistant and susceptible to straighthead have been identified. We established that low nitrogen levels are important for the occurrence of straighthead. Tests are being conducted to optimize levels of nitrogen and the straighthead-inducing compound MSMA. (NP304, Comp. VII; NP302, Comp. 2)
Impacts
(N/A)
Publications
- Gealy, D.R., Bradford, K.J., Hall, L., Raybould, A., Wolt, J., Zilberman, D. 2007. Implications of gene flow in the scale-up and commercial use of biotechnology-derived crops: Economic and policy considerations. Council for Agricultural Science and Technology Issue Paper 37. CAST, Ames, Iowa. 24 p.
- Miller, H.B., Ledbetter, C.K., Bennett, S. 2008. Using a commercial DNA extraction kit to obtain RNA from mature rice kernels. Plant Biotechnology Journal. 3:360-363.
- Delouche, J.C., Burgos, N.R., Gealy, D.R., De San Martin, G.Z., Labrada, R. , Larinde, M., Rosell, C. 2007. Weedy Rices-Origin, Biology, Ecology, and Control. FAO Plant Production and Protection Paper 188, FAO Rome. 144 p.
- Miller, H.B., Beaty, B. 2007. Distribution of arsenic and other minerals in rice plants affected by natural straighthead. Agronomy Journal. 99:1675- 1681.
- Miller, H.B. 2007. Poultry litter induces tillering in rice. Journal of Sustainable Agriculture. 31:151-160.
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Progress 10/01/06 to 09/30/07
Outputs
Progress Report Objectives (from AD-416) Establish distributions of red rice types in the U.S., their intercrossing rates with rice, and visual and marker classes for accurate identification of resistant hybrids. Improve the long-term sustainability of weed control with reduced inputs by discovering, developing, or improving rice germplasm that suppresses barnyardgrass with minimal herbicide application. Identify the specific growth response(s) elicited by poultry litter in rice plants and determine the chemical constituents in the litter that induce these growth responses. Measure carotenoids non-destructively in single rice grains to understand the induction of carotene synthesis in rice endosperm under stress conditions of high heat and moisture. Approach (from AD-416) Distinct populations of HR (herbicide-resistant) red rice, and rice-red rice hybrids from rice fields in the southern US can be detected, identified, and managed or exploited through genetic assessment and regional distribution of red rice ecotypes, reciprocal outcrossing between rice and red rice, and hand-crossed hybrids. Identify and/or advance rice lines that have grain quality and plant types of commercial or near-commercial acceptability so that weeds may be controlled in farmer fields at reduced herbicide rates. Investigate the growth- promoting effects of poultry litter on rice beyond nutrient augmentation alone. Study how the environmental and biological stresses influence the genetic and physiological control of the induction of carotenoid synthesis that occurs during heat-stress induced PHY (a yellow discoloration) of rice grains and adapt techniques to study molecular genetic differences in milled rice. Accomplishments Choice of cultivar impacts the potential for gene escape: Prevention of outcrossing between rice possessing herbicide resistance genes and weedy red rice is needed to prevent gene escape. Researchers at the Dale Bumpers National Rice Research Center at Stuttgart, AR, and collaborators at the University of Arkansas, Fayetteville, AR conducted a study to determine the outcrossing rate from a commercial hybrid and a commercial variety to numerous red rice biotypes over four planting dates. Outcrossing between the hybrid and red rice averaged 0.3% over the four planting dates and was two to nine times greater than outcrossing from the non hybrid cultivar. Thus, choice of genotype may be a more effective means to minimize the potential transfer of herbicide resistance genes to red rice than altering planting dates. (NP304, Crop Protection and Quarantine, Component VII: Weed Biology and Ecology, Problem Area VIID: Reproductive Biology and Seed Bank Dynamics as well as Component VIII: Chemical Control of Weeds, Problem Area VIIB: Herbicide Resistance and Transgenics) Identification of rice cultivars useful in controlling weeds: Weed-suppressive rice varieties can improve weed control and rice productivity in reduced-input systems, but little is known about the role roots may contribute to this weed suppression. Researchers at the Dale Bumpers National Rice Research Center in Stuttgart, AR, evaluated root interactions between rice (a C-3 photosynthesis pathway plant) and barnyardgrass (a C-4 photosynthesis pathway plant) in a four-year field study using 13C isotope depletion analysis. Asian rice varieties reduced the growth of barnyardgrass roots and shoots to a much greater extent than did common commercial rice cultivars in most years. Barnyardgrass root and shoot growth inhibition were strongly correlated over the four years, suggesting that either one of these measurements could potentially serve as a useful predictor of the other. This work confirms that weed suppressive activity was largely consistent across variable environments and that stable carbon isotope analysis can be used effectively in the investigation of crop-weed root interactions in rice systems. (NP304, Crop Protection and Quarantine, Component VII: Weed Biology and Ecology, Problem Area VIID: Reproductive Biology and Seed Bank Dynamics) Mineral content is not associated with straighthead in rice: Although application of high levels of arsenic can induce straighthead, a physiological disease causing sterility in rice, it is not known what causes this disease in commercial production systems. Research conducted at the Dale Bumpers National Rice Research Center in Stuttgart, AR, determined that mineral content (including arsenic) in various plant parts was not associated with straighthead symptoms, with the possible exception of magnesium, based on an analysis of straighthead and non- straighthead induced plants. Results also indicated that nitrogen applications, slightly higher than recommended, are effective in alleviating symptoms, thus providing a less costly alternative to the standard practice of draining fields early in the season to reduce straighthead occurrence. (NP302 Plant Biological and Molecular Processes, Component B: Biological Processes that Improve Crop Productivity and Quality) Rice cultivars from around the world vary in carotenoid levels: Carotenoids, known to be nutritionally important, have been identified in the bran layer of rice kernels. Researchers at the Dale Bumpers National Rice Research Center in Stuttgart, AR, measured the total carotenoid level in the bran of 42 rice cultivars and landraces, representing all five subspecies of rice. The average amount of carotenoids was highest in the Aus landrace, followed in order by temperate japonicas, indicas, and tropical japonicas, with aromatics having the lowest overall bran carotenoid. Amounts varied approximately four-fold within each subgroup indicating that wide diversity is available for breeding for increased levels of bran carotenoids. (NP301 Plant Genetic Resources, Genomics, and Genetic Improvement, Component 3. Genetic Improvement of Crops. Problem Statement 3B: Capitalizing on Untapped Genetic Diversity, and Problem Statement 3C: Germplasm Enhancement/Release of Improved Genetic Resources and Varieties) Stackburn susceptibility is common in domestic rice cultivars: Postharvest yellowing, or stackburn, is discoloration that can occur in paddy rice during storage, reducing the value of the crop. Identifying cultivars that do not discolor during storage would benefit the rice industry. Scientists at the Dale Bumpers National Rice Research Center in Stuttgart, AR, evaluated over 100 southern US rice cultivars for their ability to stackburn. The results showed a narrow range in yellowing, indicating that genetic variability is limited for this trait in the US genepool. These results demonstrate that geneticists will need to explore cultivars from other countries to determine if genetic resources exist that are not susceptible to postharvest yellowing. (NP302 Plant Biological and Molecular Processes, Component B: Biological Processes that Improve Crop Productivity and Quality) Technology Transfer Number of Non-Peer Reviewed Presentations and Proceedings: 4 Number of Newspaper Articles,Presentations for NonScience Audiences: 8
Impacts
(N/A)
Publications
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Progress 10/01/05 to 09/30/06
Outputs
Progress Report 1. What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? Why does it matter? A major key to success in the U.S. rice industry is development of new technologies and improved genetic materials that can lead to release of new commercial cultivars. However, rice cultivars must endure stresses imposed by the environment and by pests, which may reduce their full production and economic potential. Weeds are the most prevalent and costly pest in U.S rice production, but diseases and insects can also cause significant damage. Protection from weeds and other pests and tolerance to abiotic stresses are factors that affect quality, productivity, and value of the commercial end product. Understanding the physiology and genetics of the rice plant's response to biotic and abiotic stress is essential to optimizing rice production and quality. Weeds can be devastating to
production and, without the assistance of herbicides, weed losses in the southern U.S. alone could exceed $600 million annually. Newly introduced herbicide-resistant rice has made a positive impact on control and management of weeds. However, ecological, biological, and economic drawbacks to such technologies must be minimized to ensure the most effective long-term use of these systems. Red rice (Oryza sativa) is among the most troublesome and economically damaging weeds of rice in the U.S. because it is the same species as cultivated rice, it is an aggressive crop mimic, and it may serve as host for rice diseases. Thus, its long-term management in southern U.S. rice production systems remains difficult in spite of newly available herbicide-resistant varieties. The possibility of gene flow between cultivated rice and red rice has complicated crop management strategies, especially in herbicide- resistant systems. At DB NRRC, we are systematically collecting red rice types
representative of the diversity within U.S. rice fields and evaluating their genetic differences using DNA markers, the impact of crop management on their growth and competitive habits, their response to rice diseases, and their ability to outcross with herbicide-resistant and conventional cultivars. Potential impacts from successful completion of this research include improved ability to manage red rice weed populations and to mitigate the impacts of gene flow in rice. This work is relevant to rice growers, other rice scientists, extension and industry personnel, regulatory agencies, and policy makers. Deliverables will include knowledge of the biology and distribution of red rice biotypes, basic knowledge about the frequency of outcrossing, identification of any weed-like traits of outcrossed progeny, and development of red rice outcross identification keys based on DNA markers and visual traits. Barnyardgrass (Echinochloa crus-galli) and related Echinochloa species are among the
most widespread and troublesome weeds in U.S. rice. Previous research at DB NRRC has shown that some indica cultivars from Asia can potentially out-yield U.S. rice cultivars and/or provide exceptional suppression of barnyardgrass through competition. Furthermore, newly developed commercial rice hybrids appear to have similar competitive advantages over traditional commercial varieties. At DBNRRC, we are conducting field studies on weed-crop biological interactions and weed control. We are cooperating in breeding efforts to evaluate/select rice germplasm and breeding lines that possess the high yield and weed suppression potential as well as the acceptable grain quality. Successful completion of the weed suppression research has the potential to supplement existing weed control practices in some rice cropping systems with reduced economic and chemical inputs. This work will be relevant to rice growers, other rice scientists, and extension personnel, and may be especially of interest
to those involved in reduced input systems such as organic farming. Deliverables will include new knowledge about management and biological interactions of weeds in reduced input systems and eventually will result in new rice germplasm that suppresses troublesome weeds. Rice is considered a model system for genetic and physiological studies because of its relatively small genome and its genetic similarity to many other grain crops. Because of this, genetic information gained in rice is generally transferable to other crops. Stackburn, or postharvest yellowing, is a problem in the rice industry. Rice can become discolored as a result of poor storage conditions, reducing its economic value. Control of post-harvest handling methods and storage environments is used to prevent incidence of stackburn. We have developed a non-destructive technique to measure carotenoids in rice and have shown that stackburn induced rice contains these vitamin A precursors. The biochemical,
physiological, and genetic controls for production of yellowed rice are being investigated. Potential impacts from gaining understanding of the mechanism of yellowing could lead to a means of preventing the discoloring in storage. Moreover, the discovery of naturally occurring carotenoids in rice may be valuable for nutrition and/or marketing as they would not carry the negative perception that genetically modified crops currently have. The work is relevant to rice growers, other rice scientists, and extension and industry personnel. Deliverables include knowledge of internal control methods of rice yellowing and information about induction of the carotenoid pathway. Poultry litter has been used as a soil amendment for crop productivity. As the poultry industry has grown in the US, it has become increasingly important to find a means of utilizing the litter by-product to minimize point source pollution of surface and ground water. Knowledge of litter's specific effects, especially
the mechanisms by which plant productivity are improved would allow more effective use of litter and could increase the importance of litter as a soil amendment. In addition, organic poultry litter is an effective source of nutrients for organic farming. Poultry litter's effects on plant production in field studies are highly variable. A small-scale, controlled system to study poultry litter effects would be valuable to reduce the variability encountered in field studies and identify the major factors associated with poultry litter's impact on plant growth. We have found that poultry litter strongly affects rice plant tillering, a component of grain yield. Understanding the physiological impact of poultry litter on rice growth has the potential to increase crop production and support organic farming. The work will be relevant to rice growers, especially those interested in organic farming, other rice scientists, the poultry industry, and extension personnel. Deliverables will
include an understanding of the impact that poultry litter has on triggering tillering, a phenomenon that is not well understood, and information about how to optimize utilization of a useful but overabundant poultry by-product. Research on management strategies for weed control in rice fields addresses NP 304 Crop Protection and Quarantine, Research Component VII - Weed biology and ecology in problem area - Growth, Development and Competition and Research Component X - Weed Management Systems in problem area - Integrated Weed Management in Cropland. Research on gene flow between cultivated and red rice addresses National Program 302 - Plant Biological and Molecular Processes, Research Component 3 - Plant Biotechnology Risk Assessment, in problem area 3b Interaction of Transgenic Plants with Their Environment. Research on using poultry litter to enhance yield and tiller production in marginal soils and methods for studying stackburn and cartenoid production in stored rice support
NP302, Research Component 2 - Biological Processes that Improve Crop Productivity and Quality, problem areas 2A: Understanding Growth and Development and 2B: Understanding Plant Interactions with Their Environment. 2. List by year the currently approved milestones (indicators of research progress) Obj. 1A Red rice outcrossing effects in herbicide resistant rice [Milestone 1 (12 mo., FY06] Acquisition of new red rice accessions and suspected hybrid derivatives. Establish field nurseries, outcrossing plots, and greenhouse plantings. Begin molecular characterizations. Publish finished ongoing project on IMI-rice X red rice gene flow. [Milestone 2 (24 mo., FY07)] Continue acquisition of red rice accessions and hybrid suspects. Establish 2nd year nurseries, outcrossing plots, and greenhouse/field screens. Continue molecular analysis. Complete molecular evaluation; publish 'hand-crossed' project. Begin molecular evaluation of resistance genes in red rice. [Milestone 3 (36 mo., FY08)]
Continue 3rd year field nurseries, outcrossing plots, and greenhouse/field screens. Publish field results from reciprocal crossing studies. Continue molecular characterizations of newly acquired farm samples and other red rice types of biological or commercial interest. [Milestone 4 (48-60 mo., FY09-10)] Continue nurseries, outcrossing plots, and greenhouse/field screens as necessary. Continue acquisition of red rice and hybrids. Continue molecular analysis of red rice and correlation with various traits. Publish distribution comparisons of red rice types. Publish case studies on red rice and rice parentage. Obj. 1B Identifying barnyardgrass suppressive rice cultivars. [Milestone 1 (12 mo., FY06)] Establish field experiments comparing weed suppression from selected lines. Publish results from completed 5-year weed suppression studies comparing commercial and allelopathic cultivars. Begin molecular evaluation of suppressive/ nonsuppressive cultivars. [Milestone 2 (24 mo., FY07)]
Establish 2nd year field experiments; drop low yield/low suppression lines; advance high yield/suppression/grain quality lines. Continue molecular evaluation of suppressive/ nonsuppressive cultivars Survey databases for markers potentially useful in marker assisted selection systems. [Milestone 3 (36 mo., FY08)] Establish 3rd year field experiments; drop marginal lines; advance promising ones. Begin use of marker assisted selections for suppressive rice lines. Identify high yielding/suppressive lines for breeding program for traditional or 'organic' systems. [Milestone 4 (48-60 mo., FY09-10)] Publish information obtained from field studies and molecular studies demonstrating key traits/markers useful in selecting suppressive lines. Most suppressive, highest yielding lines tested/used in organic rice. Obj. 2A Improvement of rice growth with poultry litter components. [Milestone 1 (12 mo., FY06)] Poultry litter will be applied along with fertilizer to determine improvement of rice
growth specifically due to the poultry litter. [Milestone 2 (24 mo., FY07)] Early indicators of improved plant growth will be identified to allow more rapid turnover of experiments and avoid the necessity of waiting for yield measurements to make determinations of growth promotion. [Milestone 3 (36 mo., FY08)] Poultry litter will be extracted into various fractions, which will be tested for their growth promoting ability. [Milestone 4 (48-60 mo., FY09-10)] Chemical identification will be made of the growth promoting component(s). Obj. 2B Physiology and genetics of carotenes in stress-induced yellow rice. [Milestone 1 (12 mo., FY06)] Test-tube scale technique to induce stackburn will be used to identify causal factors; begin developing mRNA and RT(reverse transcriptase)-PCR techniques [Milestone 2 (24 mo., FY07)] Non-destructive method for detecting carotenoids will be used to screen other material (e.g., bran) in a number of cultivars and species for future phylogenetic and
molecular studies. [Milestone 3 (36 mo., FY08)] An extraction technique for endosperm carotenoids will be developed so that identification of the carotenoids by HPLC can be made. [Milestone 4 (48-60 mo., FY09-10)] The mRNA will be extracted from kernels at various stages of yellowing. RT-PCR will be carried out on this mRNA to determine the changes in expression of carotene-synthesis genes in the endosperm. 4a List the single most significant research accomplishment during FY 2006. Confirmation of gene flow between cultivated rice and red rice biotypes: Preventing outcrossing between cultivated rice and red rice, a closely related weed species, is an important component to maintaining the usefulness of herbicide-resistant rice technology that has been broadly accepted by the US rice industry. At the Dale Bumpers National Rice Research Center, Stuttgart, AR, outcrossing rates between numerous rice cultivars and red rice biotypes was determined over a five-year period using visual plant
traits that were then confirmed with multiple DNA microsatellite markers. Outcrossing rates varied widely from year to year and between different cultivated rice and red rice biotypes. These findings suggest that knowledge of the biology of rice and of local red rice biotypes, as well as their response to different environmental conditions, is necessary to fully understand and manage gene flow in rice fields. (NP 302, Component 3) 4b List other significant research accomplishment(s), if any. Development of mRNA and RT(reverse transcriptase)-PCR techniques for use on rice endosperm: Because of its relatively small genome, rice is the model system for genomic studies in grain crops. However, the rice grain has high starch content which makes the extraction of nucleic acids from mature rice kernels extremely difficult. At the Dale Bumpers National Rice Research Center, Stuttgart, AR, a protocol was developed that provides the means to extract RNA from rice endosperm more quickly,
efficiently, and cheaply than standard protocols. This technique will facilitate the study of gene function in the developing rice grain. (NP302, Component 2) Red rice contamination has impact on rice cooking quality: Weedy red rice seeds routinely contaminate commercial rice fields, and their physical and chemical properties can differ markedly from those of cultivated rice. In cooperation with the University of Arkansas- Fayetteville, laboratory research work was conducted to compare numerous physical-chemical properties, starch fine structure, and thermal properties of 16 weedy southern red rice types with two common commercial rice cultivars. Although all red rices had medium-grain shape, their physical/chemical properties were quite different from those of the commercial medium-grain Bengal, but red rice starch pasting and thermal properties were similar to those of the commercial long-grain Wells. One group of red rice types had kernel properties similar to those of Wells,
while another group had properties similar to Bengal. These kernel properties of red rice may offer an alternative way of classifying red rice in addition to traditional visually observable and genetic indices. Understanding the similarities and differences in these properties between red rice and commercial rice will demonstrate the effects of red rice contamination on overall rice grain quality. (NP302, Component 3) Vigorous plant growth of rice hybrids helps to compete against red rice weeds: Differences in imidazolinone-resistant rice cultivars, planting time, and flowering time of red rice may impact the possibility of gene flow of the herbicide resistance technology to red rice. These factors were evaluated in field experiments at Stuttgart, AR, with University of Arkansas cooperators. At least 6 of the 12 red rice biotypes flowered synchronously with both CL161 and CLXL8 rice at all four planting dates, indicating that changing the rice planting dates to avoid gene flow to
red rice is not likely to be effective means of controlling the gene flow. Yield reduction due to red rice weed pressure in the commercial hybrid rice cultivar, CLXL8, was much less than those of CL161, indicating that herbicide-resistant commercial hybrids may have the additional value by competitively suppressing red rice in addition to the control from the herbicide. (NP302, Component 2) 5. Describe the major accomplishments to date and their predicted or actual impact. The dynamics of gene flow between rice and red rice is complex and key to the understanding and long-term management of red rice in imidazolinone- resistant rice and traditional non-resistant commercial rice. As part of an ongoing effort to understand and manage unwanted gene flow between red rice and rice, a combination of visual indicators and DNA markers have now been used to identify a diverse group of red rice-rice outcrosses and to show that the outcrossing rate (and potential gene flow) between cultivated
and red rice can vary substantially depending on the environment, cultivar, and biotype. The major finding is that outcrossing between particular red rice biotypes and rice cultivars varied by as much as 1000% (10X) over a five-year period, indicating that environment, which is variable and largely uncontrollable, can significantly affect the dynamics of gene flow in field situations. A laboratory-scale method was developed to induce stackburn, a seed storage condition that results in discolored rice and decreased crop value. This technique has been used eliminate fungal involvement in stackburn, and results indicate that the discolored stackburn rice contains carotenoids. Subsequently, a new technique has been developed to more efficiently analyze the presence of carotenoids possibly induced in rice grain during storage. Research on management strategies for weed control in rice fields addresses NP 304 Crop Protection and Quarantine, Research Component VII - Weed biology and ecology
in problem area - Growth, Development and Competition and Research Component X - Weed Management Systems in problem area - Integrated Weed Management in Cropland. Research on gene flow between cultivated and red rice addresses National Program 302 - Plant Biological and Molecular Processes, Research Component 3 - Plant Biotechnology Risk Assessment, in problem area 3b Interaction of Transgenic Plants with Their Environment. Research on using poultry litter to enhance yield and tiller production in marginal soils and methods for studying stackburn and cartenoid production in stored rice support NP302, Research Component 2 - Biological Processes that Improve Crop Productivity and Quality, problem areas 2A: Understanding Growth and Development and 2B: Understanding Plant Interactions with Their Environment. 6. What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end- user (industry, farmer, other
scientists)? What are the constraints, if known, to the adoption and durability of the technology products? Results on rice natural weed suppression, red rice biology and management, detection and management of gene flow between red rice and rice, effects of poultry litter on tillering, and heat-induced discoloration of rice kernels was presented to farmers, industry representatives, small businesses, Congressional groups, officials from regulatory agencies, state and national leadership groups, researchers, visiting scientists from foreign countries, and graduate students researchers as part of field days and lab tours. 7. List your most important publications in the popular press and presentations to organizations and articles written about your work. (NOTE: List your peer reviewed publications below). Estorninos, L.E., Gealy, D.R., Wilson, C.E. 2006. Genetic analysis and reciprocal outcrossing rates of red rice types in Arkansas. In: Norman, R. J., Meullent, J.-F., Moldenhauer,
K.A.K., editors. B.R. Wells Rice Research Studies 2005, Arkansas Agricultural Experiment Station Research Series 540. p. 190-199. Available: http://www.uark. edu/depts/agripub/Publications/researchseries. Shivrain, V.K., Burgos, N.R., Gealy, D.R., Black, H.L., Estorninos, L.E. 2006. Flowering of red rice accessions from Arkansas and Clearfield cultivars in the Grand Prairie. In: Norman, R.J., Meullenet, J.-F., Moldenhauer, K.A.K., editors. B.R. Wells Rice Research Studies 2005, Arkansas Agricultural Experiment Station Research Series 540. p. 230-239. Available: http://www.uark.edu/depts/agripub/Publication/researchseries. Shivrain, V.K., Burgos, N.R., Sales, M.A., Gealy, D.R. 2005. Planting time and cultivar effects on outcrossing in Clearfield(tm) rice. In: Norman, R.L., Meullenet, J.-F., Moldenhauer, K.A.K., editors. B.R. Wells Rice Research Studies 2004, Arkansas Agricultural Experiment Station Research Series 529. p. 240-249. Available: http://www.uark.
edu/depts/agripub/Publications/researchseries.
Impacts
(N/A)
Publications
- Miller, H.B., Kay, M., Lee, F.N. 2005. Small-scale induction of postharvest yellowing of rice endosperm. Cereal Chemistry. 82(6):721-726.
- Miller, H.B., Miller, G.H., Rutger, J.N. 2005. Non-destructive measurement of carotenoids in plant tissue by fluorescence quenching. Crop Science. 45:1786-1789.
- Estorninos, L.E., Gealy, D.R., Talbert, R.E., Gbur, E.E. 2005. Rice and red rice (Oryza sativa) interference: I. Response of red rice to sowing rates of tropical japonica and indica rice cultivars. Weed Science. 53:676- 682.
- Estorninos, L.E., Gealy, D.R., Talbert, R.E., Mcclelland, M.R., Gbur, E.E. 2005. Rice and red rice interference: II. Rice response to population densities of three red rice (Oryza sativa) ecotypes. Weed Science. 53:683- 689.
- Gealy, D.R., Ottis, B., Talbert, R., Moldenhauer, K., Yan, W. 2005. Evaluation and improvement of allelopathic rice germplasm at Stuttgart, Arkansas, USA. In: Harper, J., An, M., Wu, H., Kent, J., editors. International Allelopathy Society. Proceedings and Selected Papers, Fourth World Congress on Allepathy--Establishing the Scientific Base, August 21- 27, 2005, Charles Stuart, Wagga Wagga, Australia. p. 157-163.
- Burgos, N.R., Norman, R.J., Gealy, D.R., Black, H.L. 2006. Competitive N uptake between rice and weedy rice. Field Crops Research. 98(1):1-7.
- Patindol, J., Flowers, A., Kuo, M., Wang, Y., Gealy, D.R. 2006. Comparison of physicochemical properties and starch structure of red rice and cultivated rice. Journal of Agriculture and Food Chemistry. 54(7):2712- 2718.
- Gealy, D.R., Estorninos, L., Wilson, C.E., Agrama, H. 2005. Confirmation of hybridization between rice and phenotypically distinct red rice types in Arkansas rice fields. Proceedings North Central Weed Science Society. 60:126.
- Yuan, J.S., Gealy, D.R., Stoming, T., Stewart Jr., C. 2006. Identification of genes involved in cold resistance during seed germination and postgermination of rice using comparative proteomics and genomics [abstract]. Proceedings American Society of Plant Biologists Annual Meeting. Paper No. P09042.
- Gealy, D.R. 2005. Gene flow between red rice and rice in herbicide resistant rice fields: evaluating risks and management options. Proceedings Fourth Brazilian Rice Congress, August 9-12, 2005, Santa Maria, RS, Brazil. 2:610.
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