Progress 12/15/15 to 12/14/18
Outputs
Target Audience:UNH undergraduate students and campus community: Six undergraduate students actively participated with the project experiments. This project has provided them with training in experimental design, and research methods such as laboratory analyses of plant samples. Scientific community: Research questions and results have been disseminated to the scientific community via presentations at the 2018 meeting of the International Sweet Corn Development Association, 2018 Weed Science Society of America annual meeting, 2017 Interdisciplinary Plant Group Symposium at the University of Missouri, 2016 tri-societies meeting (ASA, CSA, and SSSA), 2016 NIFA Projects Directors Meeting, UNH natural resources department, as well as to visiting scientists and collaborators at UNH. General Public: Research questions and information have been disseminated to the general public at the Macfarlane greenhouse open house. Changes/Problems:In response to feedback from both proposal reviewers and collaborators with expertise in roots and belowground competition, we decided that prior to initiating the Objective 1 experiment, we would conduct a screen of maize lines to look at intraspecific variability in root foraging traits, specifically morphological plasticity. Thus far, no one has established to what extent intraspecific variation exists in root morphological plasticity, as well as whether roots display tradeoffs between morphological plasticity and other foraging traits. We screened 12 recombinant inbred lines of maize (B73 X Mo17, IBM population) for morphological plasticity within heterogeneously distributed resources. We selected the IBM population because previous work has shown these lines to have considerable variation in root architecture. This would allow us to examine whether certain architectural traits can predict morphological plasticity. We used results from this first experiment (the maize screen) to select four maize lines to be used in the Obj 1 experiment. Additionally, after receiving feedback from other researchers studying belowground competition, we decided to use rhizo (or window)-boxes as growing containers throughout our experiment. Previous work has shown that forcing the roots to be grown in an almost 2-dimensional plane facilitates root identification to species, one of the biggest challenges with studying belowground competition. This method has been shown to be more reliable and feasible compared to root dye-injection. In response to proposal reviewer feedback, and to fully utilize the rhizo-box approach, we decided to limit our experiments to the greenhouse instead of scaling up to the field. In Experiment 2, we evaluated maize and weed foraging strategies in response to both spatially heterogeneous and homogeneously distributed soil resources. From this experiment, we identified a number of issues that would likely arise from conducting a competition experiment between maize and the weed species we selected for Experiment 2. Most importantly, the large initial mass difference between maize and the weed species we selected would create challenges for the rhizobox system we developed. Because we can only grow the maize plants to approximately the V4 stage before reaching the outer edges of the rhizobox and becoming root bound, the experiment can only run for a few weeks which was not enough time for the weed species to overcome the initial size difference and would not be a sufficient competitor against the maize. Additionally, some of the weed species (e.g. Sinapsis arvensis) has extremely fine root systems which we were unable to see within the rhizobox. However, we became increasingly interested in examining which of the maize foraging traits identified in Experiment 1 (large scale versus high precision) would enhance competition for soil N. We decided the best method to answer this question would be to pair these traits against each other and examine how they affect maize N uptake and productivity under competition. Therefore, for the third experiment we selected three maize genotypes from Experiment 1 that had contrasting foraging strategies and paired them together in a full factorial competition experiment within heterogeneous and homogenous distributions of soil resources (Experiment 3). What opportunities for training and professional development has the project provided?This fellowship has provided me the opportunity to enhance both my research and data analysis skills. I have become proficient in new root image analysis software, such as SmartRoot. Additionally I have developed a strong proficiency in R, and have greatly enhanced my teaching skills by developing an R module for my mentor's multivariate statistics course. UNH has numerous opportunities for researchers to gain training in research methods and data management. For example, I organized a training for our lab with UNH's Research Data Services Librarian on best practices and new tools for data management. Working under the direction of my postdoc mentor, Dr. Rich Smith, I have been included in other projects within the lab, and have developed new skills in data collection and analysis, such as those necessary to conduct a meta- analysis. This fellowship has also provided me with a number of networking opportunities, including presenting my research at conferences, as well as with visiting scientists to UNH. Additionally, the natural resources department has allowed me to develop new collaborations with individuals with expertise different from my own. I also have been able to enhance my mentoring skills by working with both undergraduates and graduates in the lab. How have the results been disseminated to communities of interest?Results and ideas related to this project have been shared to the scientific community through the following presentations: 2016: annual meeting of the ASA, CSSA, and SSSA 2017: annual meeting of the Interdisciplinary Plant Group Symposium at the University of Missouri 2018: annual meeting of the Weed Science Society 2018: UNH undergraduate research symposium 2018: An invited seminar at the University of Denver 2018: An invited seminar at the 2018 meeting of the International Sweet Corn Development Association 2018: An invited seminar at Purdue University. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Soil resources, such as decomposing organic matter, are patchily distributed throughout the soil, resulting in an extremely heterogeneous environment. 'Root foraging' encompasses the strategies utilized by roots to find and exploit these heterogeneously distributed soil resources. One such response is 'morphological plasticity', which consists of the proliferation of root growth in response to localized nutrient enrichment. Previous research has demonstrated considerable interspecific variation in root morphological plasticity, which may or may not increase N capture from heterogeneously distributed resources. Thus far, no one has established to what extent intraspecific variation exists in root morphological plasticity. Additionally, few studies have examined which root foraging strategies enhance maize competitive ability. In Experiment 1, we screened 12 recombinant inbred lines of maize (B73 X Mo17, IBM population) for morphological plasticity within heterogeneously distributed resources. At the University of New Hampshire MacFarlane Greenhouse, we utilized root window (or rhizo-) boxes as growing containers to facilitate the visualization and measurement of root architectural traits, as well as root proliferation within nutrient patches. We hypothesized that maize lines which produced a greater total number and length of lateral roots would exhibit greater morphological plasticity, measured as the percent of root surface area located within resource patch. However, contrary to our expectations, we found no relationship between root architectural traits and morphological plasticity. Generally, we found a negative relationship between root foraging traits associated with larger scale foraging (total root surface area, total root length, total shoot and root biomass) and foraging within nutrient rich patches (precision foraging). In Experiment 2, which ran from November 2016 to April 2017, I characterized root morphological plasticity and N uptake in maize and common agricultural weeds (Obj. 1). We continued to utilize the rhizo-boxes in the UNH Macfarlane Greenhouses. We selected four maize lines from Experiment 1 found to vary in their root foraging traits: 2 lines that exhibited high precision foraging (M0063 and M0167) and 2 lines that exhibited high scale foraging (M0005 and M0013). We compared these maize lines to four common agricultural weeds: Setaria faberi, Abutilon theophrasti, Echinocloa crus-galli, and Sinapsis arvensis. Both the maize lines and weed species were grown in rhizo-boxes with heterogeneous (nutrients concentrated in patches) and homogeneous (nutrients evenly distributed throughout the container) distributions of soil resources. We found that both the maize and weeds increased shoot biomass in the heterogeneous compared to homogeneous resource distribution. However, the weed species exhibited greater plasticity in shoot growth (a greater increase in shoot productivity in the heterogeneous compared to homogeneous resource distribution) compared to the maize genotypes. Interestingly, we found a positive relationship between shoot biomass and morphological plasticity within the weed species but not in the maize genotypes. In Experiment 3, which ran from June 2017 to November 2017, we selected three maize lines from Experiment 1 that varied in their root foraging traits: 1) high precision foraging, low scale foraging; 2) low precision foraging, high scale foraging; and 3) high precision and high scale foraging. Each of these maize lines were paired in a full factorial experiment to examine which root traits have the strongest influence on the outcome of competition in both heterogeneous and homogenous soil conditions. All samples have finished being processed and data collection is finished. We are currently in the process of data analysis and writing manuscripts for publication.
Publications
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2017
Citation:
Lowry, CJ, M Ryan, RG Smith. 2017. Maize root architectural traits influence morphological plasticity and response to patchy resources. Interdisciplinary Plant Group Symposium at the University of Missouri, Columbia, MO.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2016
Citation:
Lowry, C J, M Ryan, RG Smith. 2016. Root morphological plasticity in maize and its influence on N uptake from patchy resources. ASA, CSA, SSSA Annual Meeting, Phoenix, AZ.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2018
Citation:
Lowry CJ. November 2018. Using rhizoboxes to understand corn root foraging strategies. Annual meeting of the International Sweet Corn Development Association. Wisconsin Dells, WI.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2018
Citation:
Lowry, CJ, M Ryan, RG Smith. 2018. Root Foraging Strategies of Maize and Four Common Agricultural Weeds. Weed Science Society of America Annual Meeting. Oral Presentation.
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Progress 12/15/16 to 12/14/17
Outputs
Target Audience:UNH undergraduate students: Threeundergraduate students and one recent college graduate have been actively participating with project experiments. This project has provided them with training in experimental design, and research methods such as laboratory analyses of root and soil samples. UNH graduate students: As part of my fellowship, I developed an R module for my primary mentor's graduate level multivariate statistics course and held two introduction to R workshops for UNH graduate students enrolled in the class. Scientific community: Research questions and results have been disseminated to the scientific community via presentations at the 2017 Interdisciplinary Plant Group (IPG) Meeting at the University of Missouri,as well as to visiting scientists and collaborators at UNH. General Public: Research questions and information have been disseminated to the general public at the Macfarlane greenhouse open house. Changes/Problems:In Experiment 2, we evaluated maize and weed foraging strategies in response to both spatially heterogeneous and homogeneously distributed soil resources. From this experiment, we identified a number of issues that would likely arise from conducting a competition experiment between maize and the weed species we selected for Experiment 2. Most importantly, the large initial mass difference between maize and the weed species we selected would create challenges for the rhizobox system we developed. Because we can only grow the maize plants to approximately the V4 stage before reaching the outer edges of the rhizobox and becoming root bound, the experiment can only run for a few weeks which was not enough time for the weed species to overcome the initial size difference andwould notbe a sufficient competitor against the maize. Additionally, some of the weed species (e.g. Sinapsis arvensis) has extremely fine root systems which we were unable to see within the rhizobox. However, we became increasingly interested in examining which of the maize foraging traitsidentified in Experiment 1 (large scale versus high precision) would enhance competition for soil N. We decided the best method to answer this question would be to pair these traits against each other and examine how they affect maize N uptake and productivity under competition. Therefore, for the third experiment we selected three maize genotypes from Experiment 1 that had contrasting foraging strategies and paired them together in a full factorial both within heterogenous and homogenous distributions of soil resources (Experiment 3). What opportunities for training and professional development has the project provided?This fellowship has provided me the opportunity to enhance both my research and data analysis skills. I have developed a strong proficiency in R, and havegreatly enhanced my teaching skills by developing an R module for my mentor's multivariate statistics course. Working under the direction of my postdoc mentor, Dr. Rich Smith, I have been included in other projects within the lab, and have developed new skills in data collection and analysis, such as those necessary to conduct a metaanalysis. This fellowship has also provided me with a number of networking opportunities, including presenting my research at conferences, as well as with visiting scientists to UNH. Additionally, the natural resources department has allowed me to develop new collaborations with individuals with expertise different from my own. I also have been able to enhance my mentoring skills by working with both undergraduates and graduates in the lab. How have the results been disseminated to communities of interest?Results and ideas related to this project have been shared at the 2017Interdisciplinary Plant Group (IPG) Symposium at the University of Missouri, and to the local community at the 2016 UNH Macfarlane Greenhouse open house, as well aswithin meetings with project collaborators. What do you plan to do during the next reporting period to accomplish the goals?We willcontinue to process samples, analyze data, and prepare manuscripts for publication for the first (intraspecific variation in maize morphological plasticity),second experiment (morphological and physiological plasticity in maize and weeds), and third experiment (maize root foraging traits inflience on belowground competition).
Impacts
What was accomplished under these goals?
Soil resources, such as decomposing organic matter, are patchily distributed throughout the soil, resulting in an extremely heterogeneous environment. 'Root foraging' encompasses the strategies utilized by roots to find and exploit these heterogenously distributed soil resources. One such response is 'morphological plasticity', which consists of the alteration of root growth and architecture in response to localized nutrient enrichment. Previous research has demonstrated considerable interspecific variation in root morphological plasticity, which may or may not increase N capture from heterogeneously distributed resources. Thus far, no one has established to what extent intraspecific variation exists in root morphological plasticity. Additionally, little work has been done to examine which root foraging strategies enhance maize competitive ability. In Experiment 1, we screened 12 recombinant inbred lines of maize (B73 X Mo17, IBM population) for morphological plasticity within heterogeneously distributed resources. This population has previously been shown to have considerable variation in root architecture. At the University of New Hampshire MacFarlane Greenhouse, we utilized root window (or rhizo-) boxes as growing containers to facilitate the visualization and measurement of root architectural traits, as well as root proliferation within nutrient patches. We hypothesized that maize lines which produced a greater total number and length of lateral roots would also exhibit greater morphological plasticity, measured as the ratio of root length in nutrient patches to control cores. However, contrary to our expectations, we found that as the total number of both axial and lateral roots increased, root morphological plasticity decreased. Genereally, we found a negative relationship between root foraging traits associated with larger scale foraging (number of axial and lateral roots, and root system convex hull area) and foraging within nutrient rich patches (precision foraging).This suggests that maize lines which diverted a greater amount of carbon and energy into foraging for soil resources throughout the entire root system (scale foraging)had less energy and carbon reserves to initiate root proliferation within nutrient rich patches.We are currently processing the remaining maize root and shoot tissues to determine the percent N and draw inferences on how root foraging traits influence N uptake. In Experiment 2, which ran fromNovember 2016 to April 2017, Icharacterizedroot morphological and physiological plasticity and N uptake in maize and common agricultural weeds (Obj. 1). We continued to utilize the rhizo-boxes in the UNH Macfarlane Greenhouses. We selected four maize lines from Experiment 1 found to vary in their root foraging traits: 2 lines that exhibited high precision foraging(M0063 and M0167)and 2 lines that exhibited high scale foraging (M0005 and M0013). We compared these maize lines to four common agricultural weeds: Setaria faberi, Abutilon theophrasti, Echinocloa crus-galli, and Sinapsis arvensis. Both the maize lines and weed species were grown in rhizo-boxes with heterogenous (nutrients concentrated in patches) and homogenous (nutrients evenly distributed throughout the container) distributions of soil resources. We are currently in the process of analyzing data to examine whether root foraging traits effecton N uptake varies with the distribution of nutrients in the soil. In Experiment 3, which ran from June 2017 to November 2017, we selected three maize lines from Experiment 1 that varied in their root foraging traits: 1) high precision foraging, low scale foraging; 2) low precision foraging, high scale foraging; and 3) high precision and high scale foraging. Each of these maize lines werepaired in a full factorial experiment to examine whichroot traits have the strongest influence on the outcome of competition in both heterogenous and homogenous soil conditions. This greenhouse experiment has finished and we are currenty processing samples and analyzing data.
Publications
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2017
Citation:
Lowry, C.J., M. Ryan, R.G. Smith. Maize root architectural traits influence morphological plasticity and response to patchy resources. Interdisciplinary Plant Group Symposium at the University of Missouri , Columbia, MO.
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Progress 12/15/15 to 12/14/16
Outputs
Target Audience:UNH undergraduate students: Two undergraduate students and one recent college graduate have been actively participating with project experiments. This project has provided them with training in experimental design, and research methods such as laboratory analyses of root and soil samples. Scientific community: Research questions and results have been disseminated to the scientific community via presentations at: 2016 tri-societies meeting (ASA, CSA, and SSSA), 2016 NIFA Projects Directors Meeting, UNH natural resources department, as well as to visiting scientists and collaborators at UNH. General Public: Research questions and information have been disseminated to the general public at the Macfarlane greenhouse open house. Changes/Problems:In response to feedback from both proposal reviewers and collaborators with expertise in roots and belowground competition, we decided that prior to initiating the Objective 1 experiment, we would conduct a screen of maize lines to look at intraspecific variability in root foraging traits, specifically morphological plasticity. Thus far, no one has established to what extent intraspecific variation exists in root morphological plasticity, as well as whether roots display tradeoffs between morphological plasticity and other foraging traits. We screened 12 recombinant inbred lines of maize (B73 X Mo17, IBM population) for morphological plasticity within heterogeneously distributed resources. We selected the IBM population because previous work has shown these lines to have considerable variation in root architecture. This would allow us to examine whether certain architectural traits can predict morphological plasticity. We have used results from this first experiment (the maize screen) to select four maize lines to be used in the Obj 1 experiment. Additionally, after receiving feedback from other researchers studying belowground competition, we decided to use rhizo (or window)-boxes as growing containers throughout our experiment. Previous work has shown that forcing the roots to be grown in an almost 2-dimensional plane facilitates root identification to species, one of the biggest challenges with studying belowground competition. This method has been shown to be more reliable and feasible compared to root dye-injection. In response to proposal reviewer feedback, and to fully utilize the rhizo-box approach, we decided to limit our experiments to the greenhouse instead of scaling up to the field. What opportunities for training and professional development has the project provided?This fellowship has provided me the opportunity to enhance both my research and data analysis skills. I have become proficient in new root image analysis software, such as SmartRoot. Additionally, I have developed a strong proficiency in R. UNH has numerous opportunities for researchers to gain training in new research methods and data management. For example, I organized a training for our lab with UNH's Research Data Services Librarian on best practices and new tools for data management. Working under the direction of my postdoc mentor, Dr. Rich Smith, I have been included in other projects within the lab, and have developed new skills in data collection and analysis, such as thosenecessary to conduct a meta-analysis. This fellowship has also provided me with a number of networking opportunities, includingpresenting my research at conferences, as well as with visiting scientists to UNH. Additionally, the natural resources department has allowed me to develop new collaborations with individuals with expertise different from my own. Finally, I have been able to enhance my mentoring skills byworking with both undergraduates and graduates in the lab. How have the results been disseminated to communities of interest?Results and ideas related to this project have been shared at the 2016 meeting of tri-socities (ASA, CSA, and SSSA), at the 2016 NIFA Project Directors Meeting, to the local community at the 2016 UNH Macfarlane Greenhouse open house, and within meetings with project collaborators. What do you plan to do during the next reporting period to accomplish the goals?Within the next year, we plan on finishing our second experiment comparing root morphological and physiological plasticity in maize and common agricultural weeds. We will also continue to process samples, analyze data, and prepare manuscripts for publication for the first (intraspecific variation in maize morphological plasticity) and second experiment (morphological and physiological plasticity in maize and weeds). From May to November we will focus on Objective 2 of the proposal, evaluating how root foraging traits influence belowground competition. We will continue to use our rhizo-box experimental system in the greenhouse with 15N labeled clover residue. We will use results from experiment 2 to optimize experimental treatments and methods for the competition experiments.
Impacts
What was accomplished under these goals?
Soil resources, such as decomposing organic matter, are patchily distributed throughout the soil, resulting in an extremely heterogeneous environment. 'Root foraging' encompasses the strategies utilized by roots to exploit these patchy resources. One such response is 'morphological plasticity', which consists of the alteration of root growth and architecture in response to localized nutrient enrichment. Previous research has demonstrated considerable interspecific variation in root morphological plasticity, which may or may not increase N capture from heterogeneously distributed resources. Thus far, no one has established to what extent intraspecific variation exists in root morphological plasticity. We screened 12 recombinant inbred lines of maize (B73 X Mo17, IBM population) for morphological plasticity within heterogeneously distributed resources. This population has previously been shown to have considerable variation in root architecture. At the University of New Hampshire MacFarlane Greenhouse, we utilized root window (or rhizo-) boxes as growing containers to facilitate the visualization and measurement of root architectural traits, as well as root proliferation within nutrient patches. We hypothesized that maize lines which produced a greater total number and length of lateral roots would also exhibit greater morphological plasticity, measured as the ratio of root length in nutrient patches to control cores. However, contrary to our expectations, we found that as the total number of both axial and lateral roots increased, root morphological plasticity decreased. This suggests that maize lines which diverted a greater amount of carbon and energy into total lateral root formationhad less energy and carbon reserves to initiate root proliferation within nutrient rich patches. Future work will examine howmaize morphological plasticity affected N uptake. From November 2016 to March or April 2017, I am characterizing root morphological and physiological plasticity and N uptake in maize and common agricultural weeds (Obj. 1). We arecontinuing toutilizethe root window (or rhizo-) boxes. We plan on having a total of 8 replications (which are blocked by both space and time) and we are currently finished with 5 of the 8 replications.
Publications
- Type:
Conference Papers and Presentations
Status:
Submitted
Year Published:
2016
Citation:
Lowry, C.J., M. Ryan, R.G. Smith. Root morphological plasticity in maize and its influence on N uptake from patchy resources. ASA, CSA, SSSA 2016 meeting, Phoenix, AZ.
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