2008 Annual Report
1a.Objectives (from AD-416)
Determine the interaction of conservation tillage, fungicide treatments, and peanut cultivars in sub-surface drip irrigation on oil amount and quality.
1b.Approach (from AD-416)
The effectiveness of most production practices is evaluated at harvest by examining final yield. However, an understanding of the mechanisms that drive these final yield numbers is vital in determining the efficacy of production strategies and technologies. Most causal mechanisms are physiologically based; therefore, an examination of the physiological response to the production environment can help determine how production practices succeed or fail. Research will be conducted to investigate and improve the understanding of the physiological responses to environment, climate, and production practices that ultimately determine peanut yield and quality. Major emphasis will be directed towards examining the effects of irrigation type and amount on peanut physiological water use and evaluating water-use efficiency under varying water environments. Emphasis will also be placed on plant and kernel susceptibility to aflatoxin contamination and tomato spotted wilt virus, and their effects on water use and other plant and kernel physical characteristics.
A quality natural resource base is a vital factor in the viability of rural economies to sustain agricultural productivity. Available water supply is being stretched by rapidly growing demands for water by urban populations, irrigated agriculture, industry/energy sectors, and in-stream flow requirements. The dilemma for producers and local economies is finding solutions that help reduce irrigation and natural resource consumption while at the same time maintaining and or enhancing producer net returns.
Data is currently being analyzed on appropriate physiological and genetic responses to drought obtained from tillage X irrigation study. A study examining early drought responses (the period determined to be the most successful in increasing water-use efficiency) was completed. Samples are currently being analyzed for DNA sequencing variability. Data from the two year rainout shelter study is being analyzed and compiled. Data analysis from the two year study examining physiological and genetic responses in the field and Tomato Spotted Wilt Virus resistance among insecticide treatments and peanut varieties is ongoing. Protocols for Polymerase Chain Reaction analysis of Tomato Spotted Wilt Virus genetic material were established and tested. A new field testing method utilizing thrips control boxes is being conducted to determine the variability in Tomato Spotted Wilt Virus infection severity among controlled periods of thrips (and infection) exposure. This technique overcomes the limitation of mechanical inoculation that can only be accomplished at very young plant developmental stages. Ongoing evaluations of peanut breeding lines are being conducted. For the current crop year: 15 acres of peanut breeding lines and advanced lines have been planted; 588 breeding progeny lines arranging from F2 to F5 are being been grown at Dawson, GA; and 163 breeding lines and 236 breeding lines were planted at Headland, AL and Brownfield, Texas, respectively. Advanced line tests have been conduced at five locations in four states (TX, AL, GA, and MS) with various numbers of lines in each state. Forty-eight crosses were made in the greenhouse in 2008. Two advanced lines AT27-1516 and AT3-1114 have been planted on a total of 10 acres at Headland, AL in preparation for a variety release in 2009.
This research addresses National Program 302 Plant Biological and Molecular Processes, Component 1 Functional Utilization of Plant Genomes: Translating Plant Genomics into Crop Improvement, Problem Statement 1B Applying Genomics to Crop Improvement; and addresses Component 2 Biological Processes that Improve Crop Productivity and Quality, Problem Statement 2A Understanding Growth and Development and Problem Statement 2B Understanding Plant Interactions with Their Environment.
Testing the comparability of ELISA and RT-PCR for the detection of Tomato spotted wilt virus infection in peanut. Tomato spotted wilt virus (TSWV) is the most economically devastating disease facing peanut producers today. However, very little is known about the biology of the virus or the crop response to infection. Having the ability to accurately and sensitively detect viral infection in plants that are evaluated for physiological performance and tolerance of the disease is crucial. The current method is ELISA testing, an immunological test, but the possibility of increased sensitivity or greater accuracy exists for genetic testing of viral testing or reverse transcriptase-polymerase chain reaction (RT-PCR). However, RT-PCR requires more expertise, specialized equipment, and is more expensive than ELISA testing. Comparing the performance of ELISA and RT-PCR for viral testing in peanut was essential for determining the relevance of application of the more expensive RT-PCR technology. Plants from various regions in the southeast were tested for TSWV infection using both ELISA and RT-PCR and results were compared. Research showed that RT-PCR showed no increased sensitivity or accuracy over ELISA testing indicating that the more economical ELISA technique was most appropriate for testing peanut tissue. This research has the potential to save USDA-ARS and University testing facilities additional cost that would be incurred by transferring to the RT-PCR technique. This accomplishment addresses National Program 302 Plant Biological and Molecular Processes, Component 1 Functional Utilization of Plant Genomes: Translating Plant Genomics into Crop Improvement, Problem Statement 1B Applying Genomics to Crop Improvement.
Carbon isotope evaluation of water-use efficiency in irrigated and non-irrigated production. Water scarcity in agricultural production is a problem faced by all growers in the U.S. whether it is due to season-long drought conditions in semi-arid regions or to untimely growth season rainfall in otherwise high rainfall regions. Therefore, increasing crop water-use efficiency is becoming a more critical research objective as drought conditions worsen every year. The seasonal water-use efficiency of developing peanut breeding lines was evaluated in the project “Heritability Estimates for Drought Resistance Related Traits in Cultivated Peanut (Arachis hypogaea L.)”. Levels of inherent water-use efficiency were evaluated and the variability among genotypes that would be available for future breeding efforts aimed at increasing water-use efficiency in peanut was quantified. The primary results generated from this research have been presented on 2008 APRES meeting at Oklahoma City. Information about whether or not genetic variation exists and identification of those genotypes with enhanced water-use efficiency must be made available before further progress can be made in breeding for enhanced water-use efficiency. This accomplishment addresses National Program 302 Plant Biological and Molecular Processes, Component 2 Biological Processes that Improve Crop Productivity and Quality, Problem Statement 2A Understanding Growth and Development and Problem Statement 2B Understanding Plant Interactions with Their Environment.
Acclimation response of peanut to deficit irrigation: pinpointing water application to increase drought tolerance. Water scarcity in peanut production is a problem across the U.S. Building on previous research from Rowland that showed the benefit of exposure to early season drought for acclimating the crop to drought later in the season, experiments were completed and data evaluated for five early deficit periods of differing duration. Two distinct drought response mechanisms were detected between drought tolerant and resistant peanut cultivars. Ongoing molecular analysis (454 sequencing) is being conducted to determine the accompanying genetic changes that occur during early season drought stress. Both physiological and possible genetic mechanisms identified in this study have the potential to serve as drought tolerance markers that could be selected for in a breeding program. This accomplishment addresses National Program 302 Plant Biological and Molecular Processes, Component 2 Biological Processes that Improve Crop Productivity and Quality, Problem Statement 2A Understanding Growth and Development and Problem Statement 2B Understanding Plant Interactions with Their Environment.
5.Significant Activities that Support Special Target Populations
|Number of Non-Peer Reviewed Presentations and Proceedings||3|
|Number of Newspaper Articles and Other Presentations for Non-Science Audiences||3|
Rowland, D., Sorensen, R.B., Butts, C.L., Faircloth, W.H., Sullivan, D.G. 2008. Canopy Characteristics and their Ability to Predict Peanut Maturity. Peanut Science (35):86-91.
Rowland, D., Faircloth, W.H., Butts, C.L. 2006. Effects of irrigation method and tillage regime on peanut reproductive processes. Peanut Science. 32:48-56.
Rowland, D., Lamb, M.C. 2006. The effect of irrigation and genotype on carbon and nitrogen isotope
composition in peanut (arachis hypogaea l.) leaf tissue
. Peanut Science.
Chen, C.Y., Nelson, R.L., Gu, C., Mensah, C., Wang, D. 2007. SSR marker diversity of soybean aphid resistance sources in North America. Genome. 50 (12):1104-1111.
Olmstead, J.W., Sebolt, A.M., Cabrera, A., Sooriyapathirana, S.S., Hammer, S., Iriarte, G., Wang, D., Chen, C.Y., Van Der Knapp, E., Iezzoni, A. 2008. Construction of an intra-specific sweet cherry (Prunus avium L.) genetic linkage map and synteny analysis with the Prunus reference map . Tree Genetics and Genomes. DOI 10.1007/s11295-008-0061-1.2008
Acosta Martinez, V., Rowland, D., Sorensen, R.B., Yeater, K.M. 2008. Microbial community structure and functionality under peanut based cropping systems in a sandy soil. Biology and Fertility of Soils. 44(5):681-692.
Guo, B., Chen, X., Dang, P.M., Scully, B.T., Liang, X., Holbrook Jr, C.C., Yu, J., Culbreath, A.K. 2008. Peanut gene expression profiling in developing seeds at different reproduction stages during Aspergillus parasiticus infection. BMC Dev. Biol. 8:12. DOI:10.1186/1471-213X-8-12.