Plant Sciences Commons^™

Growth In Response To Gibberellin In Setaria Viridis Mutants, Jayla Hampton, Rain Hongsermeier-Baxter, Joseph E. Smith, Seth Baur, Brooke Gawlick

2024 Student Academic Showcase

Gibberellin is a plant hormone that promotes growth in plant organs. Issues arising with the production and process of the hormone result in the mutation dwarfism. In this experimentation, the effects of gibberellin on dwarf Setaria viridis are isolated by controlled growth environments and treatments. The effects of the hormone treatment are measured manually over the period of growth so that the data may be analyzed and determine the cause of dwarfism in our species. In conclusion, this study offers important insights into the mechanism underlying dwarfism mutation, providing potential direction for future research and understanding plant physiology.

Unraveling Gibberellic Acid's Impact On Plant Growth: Insights From Dwarf Millet Varieties, Brandy Miskell, Jacob Campagna, Alyssa Lambert, Dean Palmer, Bruno Ninez

2024 Student Academic Showcase

Gibberellic acid (GA), derived from the Bakanae fungus Gibberella fujikuroi, acts as a plant hormone with various functions. This study compares the growth of Setaria viridis (millet) wild type with two dwarf mutant varieties (mutant 11970 and mutant 03054) to understand genetic dwarfism and GA's role. Thirty seeds of each variety were planted, with biweekly GA treatments given to four pots and two serving as controls. Results show significant differences in leaf growth, indicating GA's role in regulating plant height. However, the exact mechanisms of GA transport within plants remain unclear, warranting further research to understand its implications for plant …

Mechanisms Of Genetic Dwarfism In Dwarf Millet Genotypes, Holly Willett, Savannah Jones, Rashmi Aryal, Therese West, Maddelyne Wright

2024 Student Academic Showcase

The goal of this project was to study and determine the different forms of genetic dwarfism in millet plants. This was done by creating three different types of millet samples using two different forms of mutant seeds and also normal seeds. 6 plants of each of the three varieties were sectioned into separate pots, and then given different treatment levels of gibberellin. Two plants in each group were given no gibberellin, two were given gibberellin once a week and two were given gibberellin daily Monday-Friday. The height of each plant was then recorded once a week throughout the trial period. …

Effects Of Gibberellin On Stem Elongation, Annamarie Busch, Bryce Mcquerrey, Guillermo Bilbao Olarreaga, Duncan Krige, Eduan Van Herrden

2024 Student Academic Showcase

Plant growth hormones are widely used in the agricultural industry to manipulate the growth of crops. Dwarf mutant variants of plants have been found to have a variety of mutations that inhibit the synthesis and metabolism of gibberellin, a major plant growth hormone (Phinney 1956). Observing the effect that the application of gibberellin has on the growth in 2 types of dwarf mutant millet variants will allow us to determine the type of mutation present. Applying a gibberellin solution is expected to increase the rate of stem elongation in variants with the mutation that inhibits the production of gibberellins. If …

Native Wetland Plant Seed Collection And Cleaning Guide For The Intermountain West, Rae Robinson, Maddie Houde, Elana Feldman, Samantha R. Kurkowski, Nathan M. Crawford, Stephanie Aristizabal, Karin M. Kettenring

All Current Publications

Collecting and cleaning seeds from wildlands is an essential part of ecosystem restoration, management, and conservation. Here, we summarize best practices for native wetland plant seed collection and cleaning in the Intermountain West.

A companion guide on seed testing, "Seed Viability Testing Guide for Common Wetland Plant Species," is also available (https://digitalcommons.usu.edu/extension_curall/2389/).

Examination Of Greenhouse Conditions That Influence Scale Infestation Rates On Begonia, Madeline M. Cusick

Honors College Theses

Scale insects are common pests within greenhouse and agricultural settings. I quantified scale infestation on Begonia x Richmondensis, also known as the Dragon Wing begonia, within the Armstrong Campus Greenhouse from March to November of 2023. Six different treatments accounted for variations in sunlight, humidity, and temperature within the greenhouse with the goal of determining the insect’s preferred environmental conditions. Morphological comparisons were also made between host plant Dragon Wing begonia and other begonias present within the greenhouse. Analysis indicated a significant difference in scale presence on replicate plants by zone and sunlight treatments, with more plants hosting at least …

Continuous Mowing Differentially Affects Floral Defenses In The Noxious And Invasive Weed Solanum Elaeagnifolium In Its Native Range, Alejandro Vasquez, Alexa Alaniz, Robert K. Dearth, Rupesh R. Kariyat

Biology Faculty Publications and Presentations

In weeds, disturbance has been found to affect life history traits and mediate trophic interactions. In urban landscapes, mowing is an important disturbance, and we previously showed that continuous mowing leads to enhanced fitness and defense traits in Solanum elaeagnifolium, Silverleaf Nightshade (SLN). However, most studies have been focused on foliar defenses, ignoring floral defenses. In this study we examined whether continuous mowing affected floral defenses in SLN using mowed and unmowed populations in South Texas, their native range. We found flowers of mowed SLN plants larger but lighter than unmowed plants. Additionally, flowers on plants that were mowed …

Stratification Of Potassium And Phosphorus In Tillage Vs. No-Till Systems And Uptake In Corn (Zea Mays) In Western Kentucky, Ava Isaacs, Kyle Krieger, Christopher Powell

Scholars Week

There are 12 nutrients essential for plant growth, two of these are phosphorus and potassium. The demand and need for these nutrients are very high in agricultural systems including corn. Phosphorus stimulates root and shoot growth and is essential for seedling growth and stability. Potassium increases tolerance to water stress, as well as resistance to disease, these are both critical in terms of soil fertility and in determining what fertilizers to apply as well as the amount of fertilizer needed. Both nutrients are not readily available for plant uptake in the soil and are largely lost during harvest, which could …

Effect Of Lowered Light Quality (R:Fr Ratio) At Targeted Organs On Branching Of Trifolium Repens, M J.M Hay, Ch Robin, P C.D Newton, A Cresswell, J Tilbrook

IGC Proceedings (1997-2023)

This report examined results from four similarly conducted experiments using Trifolium repens in which the R:FR ratio but not the photosynthetically active radiation (PAR) of incident light was altered at specific organ(s) of several successive phytomers or just at a single phytomer. Results indicate the local response to lowered R:FR light treatment was similar irrespective of the number of phytomers treated. This response pattern provides the means whereby plants can initiate strong localised responses to a heterogeneous light environment.

Theoretical And Observed Relationships Between Defoliation And Partitioning In Grasses, C P.D. Birch, B Thornton

IGC Proceedings (1997-2023)

A model is presented that analyses the potential effect of vertebrate grazing on the partitioning of grasses. Its conclusions are: 1) When grazing is sufficiently frequent and severe, grasses can increase their net increase in biomass by partitioning growth to reserves. 2) Partitioning growth to reserves greatly reduces leaf growth between defoliations. After repeated clipping, dryland browntop (Agrostis castellana) and red fescue (Festuca rubra) allocated a smaller proportion of growth between defoliations to leaves than ryegrass (Lolium perenne) or rough meadow-grass (Poa trivialis). Browntop and fescue achieved less leaf growth than ryegrass …

Effects Of Light Intensity And Defoliation On The Receptiveness For Primary Induction In Festuca Pratensis Huds, Lars T. Havstad

IGC Proceedings (1997-2023)

Seedlings of Festuca pratensis Huds. (cv. Salten) were raised at three different light intensities (141, 85 or 28 (mol m-2s-1 ) for 7 weeks after emergence and then either left uncut or defoliated 40 or 80% of total leaf area, before transfer to primary induction (6°C, natural short days) for 12, 15 or 18 weeks. Percentage of heading plants was more affected by the duration of primary induction than by light intensity and defoliation prior to induction. The results lend no support to the existence of a juvenile stage in seedlings of Festuca pratensis. Defoliation had less influence on …

Water Use Efficiency In Chilean And Argentine Humid Temperate Grass-Legume Pastures, H G. Landi, M H. Wade, V Garcia De Cortazar, D E. Dalla Valle

IGC Proceedings (1997-2023)

At two sites in Argentina and Chile five levels of water input were applied to four sown pastures of varying ages during spring and summer. The pastures consisted principally of C3 grasses and legumes, some of which were sown such as Lolium perenne, Trifolium repens, Dactylis glomerata. Dry matter (DM) production was measured and related to the estimated total evapotranspiration (ET): responses were both highly linear. Both responses to ET and absolute yields were higher at the Argentinian than at the Chilean site: respectively 10.7 and 15.2 kg DM/mm water evapotranspired. Nevertheless the calculated indices of sensitivity (Ky) of Doorenbos …

Effects Of Accelerate Ageing And Low Temperatures On Germination Of Range Grasses, C Cabeza, R E. Brevedan, M G. Klich, M A. Varillas

IGC Proceedings (1997-2023)

Accelerated ageing and cold tests were used to determine the seed vigour of different valuable forage grasses from the temperate semiarid region of Argentina (Piptochaetium napostaense, Poa ligularis, Stipa longiglumis, Stipa tenuis, Digitaria californica, Pappophorum subbulbosum, Setaria leiantha, Sorghastrum pellitum, Trichloris crinita). In general, warm season species showed greater vigour than cool season species.

Leaf Anatomy And Ultrastructure Of Poa Ligularis After Defoliation And Water Stress, M G. Klich, R E. Brevedan, S C. Villamil

IGC Proceedings (1997-2023)

The objective of this study was to determine the effect of defoliation and water stress on leaf anatomy and the mesophyll cell ultrastructure of Poa ligularis. Anatomical differences were detected mainly at epidermal level. Under water stress, leaf roughness was enhanced since the epidermal-cell surface contours became conspicuous. Under defoliation the microscopic roughness decreased as a result of fewer epicuticular wax crystals being formed. Defoliation produced an enhancement of the interlamellar spaces in the irrigated plantís chloroplast. Under no defoliation conditions, chloroplast structure was not affected by water stress. When subjected to water stress, lightly defoliated plants presented chloroplasts …

Effects Of Water Stress On Germination And Seedling Growth Of Lovegrass Species, R E. Brevedan, M G. Klich, E E. Sanchez

IGC Proceedings (1997-2023)

Seeds of seven cultivars of lovegrass species Ermelo, Morpa and Tanganyika weeping lovegrass (Eragrostis curvula var. curvula, Don Eduardo INTA (E. curvula var. robusta), Cochise lovegrass (E. lehmanniana x E. trichophera), A-68 Lehmann lovegrass (E. lehmanniana Nees) and Catalina boer lovegrass (E. curvula var. conferta) were germinated at different water potentials. Total germination percentage differed within cultivars according to water availability, although there were no great differences between the germination of the cultivars within any given water potential. The only exception was Don Eduardo INTA which had lower germination values. A marked …

Leaf Growth And Anatomy During Winter Droughting Of Tetrachne Dregei Plants, M G. Klich, R E. Brevedan, H Laborde

IGC Proceedings (1997-2023)

The purpose of this work was to study the leaf growth and anatomy of Tetrachne dregei plants when they were subjected to a winter drought period. Plants were grown in semicontrolled conditions under two soil moisture regimes: irrigated and non-irrigated. Anatomical characterization was made using optical and scanning electron microscopy. No differences were found in stomatal index, stomatal length and epidermal cell size, between irrigated and non-irrigated plants. The adaxial epidermis of water stressed plants was more pubescent. Leaf abaxial epidermis of non-irrigated plants showed more intercostal plates of crystallized epicuticular wax than that of the irrigated ones. Leaf tissue …

The Interaction Between Root Distribution And Pasture Growth During Water Deficit, D J. Barker, N Dymock

IGC Proceedings (1997-2023)

Quantification of water-limited pasture growth is of interest in agriculture since it allows prediction of impaired animal production during drought, and is the basis for scheduling irrigation. Experimental work on two dairy pastures 25 km south-west of Palmerston North, New Zealand found 50% of root mass was in the top 2.3 cm of soil. Soil moisture was, similarly, not uniformly distributed down the soil profile and dried most rapidly in the top 20†cm of soil. Leaf appearance rate was more strongly correlated with water status nearer the soil surface (r = 0.52 & 0.63 for 0-5 & 10-15 cm depth, …

Effects Of Phytohormone On Lateral Bud Elongation And Acidinvertase Activity During The Regrowth Of Sorghum Bicolor M., H Nojima, Y Takasaki, A Isoda

IGC Proceedings (1997-2023)

The relationships of phytohormone and sucrose metabolism in the stem ofoesorghum after cutting were studied using the stem disks treated with various plantoegrowth regulators The release of buds after incubating was accelerated by 6-benzyladenoprine riboside (6- BAR) treatment. But, on abcisic acid (ABA) andoeindole acetic acid (IAA ) treatment the release of buds was retarded. The length ofoeelongated buds on all hormonal treatments was shorter than the non-treated at the end of incubated period tested. Invertase activities were stimulated on all hormonal treatments. On 6-BAR treatment, invertase activities were the highest. But there were no relationships between invertase activities and …

Management Of Tall Wheatgrass Based On The Leaf Appearance During Spring, S Laplace, M A. Brizuela, M S. Cid

IGC Proceedings (1997-2023)

The objectives of this study were to determine the date of transition from vegetative to reproductive stage at different defoliation frequencies in tall wheatgrass (Thinopyrum ponticum). In addition, we assessed the relationship between the spring temperatures and the rate of leaf appearance. To meet both objectives we had defoliated and undefoliated plant plots at Balcarce Experiment Station, Argentina. The different defoliation treatments (every 7, 14, 21 and 28 days) delayed or avoided the manifestation of the reproductive stage. The apexes of undefoliated plants began to rise on October 12, while defoliated ones slowed that elevation or the same …

Movement Of Allelopathic Compound Coumarin From Plant Residue Of Sweet Vernalgrass (Anthoxanthum Odoratum L.) To Soil, Yoshito Yamamoto

IGC Proceedings (1997-2023)

This study investigated the movement of coumarin, an allelopathic compound, from the plant residue of sweet vernalgrass (Anthoxanthum odoratum L.) to soil, as well as the dynamics of coumarin in soil. The level of coumarin dissolved from sweet vernalgrass plant residue in both Andosols and Cambisols, which were watered every day, peaked on the 5th day after the beginning of watering, and fell gradually with each additional of day. Specifically, the coumarin content in Cambisols on the 5th day was 14.2 ppm, which is 4 times the coumarin level found in Andosols. The recovery percentage of coumarin extracted with …

Partitioning Of Phosphorus In White Clover Populations With Different Nodulation Patterns, J R. Crush

IGC Proceedings (1997-2023)

The objective of this study was to see if a white clover (Trifolium repens L.) population selected for development of relatively few, but large nodules, differed in the way it used absorbed phosphorus, compared to a white clover population selected for many small nodules. Plants of both populations were grown in minus-nitrogen sand culture and the dry weights and phosphorus contents of shoots, roots and nodules were measured. There were no differences in growth or partitioning of dry matter or phosphorus between the clover lines.

Winter Survival And Physiology Of Contrasting Fall Dormancy Selections Of Alfalfa, J J. Volenec, S M. Cunningham, L R. Teuber

IGC Proceedings (1997-2023)

Our objective was to determine the physiological changes that accompany selection from within a germplasm for contrasting fall dormancy reaction. Selection for greater fall dormancy improved winter survival of CUF 101 from 1 to 93%. The more fall dormant CUF 101 had higher sugar concentrations in buds and roots. Roots of the more fall dormant CUF 101 also contained higher soluble protein concentrations when compared to the other CUF 101 germplasms. Root protein extracts obtained in Dec. from the more fall dormant CUF 101 contained at least one polypeptide not found in protein extracts of the other CUF 101 germplasms. …

Root Nitrogen Cycling And Alfalfa Stress Tolerance, J J. Volenec, B C. Joern, L D. Barber, S M. Cunningham, A Ourry

IGC Proceedings (1997-2023)

Our hypothesis is that certain root N pools are utilized preferentially during the early shoot regrowth. Our objective was to determine the relative contribution of crown N, root N, and specific root N pools to shoot regrowth after defoliation. We used 15N to follow N into and out of crowns, roots, and specific root N pools, to regrowing shoots after defoliation. The low molecular weight N pool (amino acids, inorganic N,...) acquired 15N rapidly within 2 d of N application. Movement of 15N into the protein-N and insoluble-N pools was delayed initially, but continued until 8 d after N application. …

Phyllochron Development In Cool-Season Forage Grasses, A B. Frank, J D. Berdahl, J F. Karn

IGC Proceedings (1997-2023)

The purpose of this study was to evaluate the relationship between grass leaf insertion rate and accumulated growing degree-days, and determine the phyllochron for five perennial forage grass species and two cultivars of each species. Species field seeded in solid stands were crested wheatgrass [Agropyron desertorum (Fisch. ex. Link) Schult.], intermediate wheatgrass, [Thinopyrum intermedium Barkw. & Dewey:Syn:A. intermedium (Host) Brauv], western wheatgrass [Pascopyrum smithii (Rybd) L ve], green needlegrass (Stipa viridula Trin.), and smooth bromegrass (Bromus inermis Leyss). Species phyllochron differences ranged from 77 GDD for Mandan 404 smooth bromegrass to 114 GDD for Lodorm …

Response To Drought Of White Clover Lines Selected For Different Stolon Morphologies, H D. Karsten, J R. Caradus, D R. Woodfield

IGC Proceedings (1997-2023)

White clover (Trifolium repens L.) lines were selected from within large and small-leaved cultivars of Grasslands Kopu and Grasslands Tahora, respectively, for long or short internodes, and for high or low branching frequency from plants grown in sun and shade (50% full sunlight). Lines were compared for drought tolerance in a perennial ryegrass (Lolium perenne L.) sward in boxes. Prior to imposing drought branching frequency selections did not differ in branching frequency, although the low branching frequency selection had a higher percentage of rooted nodes. After an imposed drought treatment sun-selected lines grew better than shade-selected lines relative …

Kentucky Bluegrass Floral Induction And Cultivar Response To Mechanical Removal Of Harvest Residue, G A. Murray, J B. Swensen

IGC Proceedings (1997-2023)

Open-field burning of post-harvest residue from Kentucky bluegrass (Poa pratensis L.) seed fields is being phased out in Washington, USA and may be banned in Idaho. Burning encourages early fall regrowth and timely completion of fall floral induction. Cultivars have different floral induction requirements and respond differently to mechanical residue removal. Our objective was to determine if length of fall floral induction requirement was related to seed yield when post-harvest residue was removed by crewcut vacuum sweeping. Floral induction requirements were not related to first-or second-year seed yields. Third-year seed yield of cultivars with long floral induction requirements declined …

The Influence Of Intensity Of Tree Thinning On The Redistribution Of Soil Water In Southern African Mopani Veld, G N. Smit, N F.G. Rethman, A Moore, A Le Roux, J S. Swart

IGC Proceedings (1997-2023)

The investigation was conducted on a densely wooded area in the Mopani veld of South Africa. Six plots were subjected to different intensities of tree thinning, ranging from a totally cleared plot (0 %) to plots thinned to the equivalent of 10%, 20%, 35%, 50% and 75% of the leaf biomass of a control plot (100%). Soil water measurements were taken at six different depths to a depth of 825 mm. The infiltration of rain water and redistribution within the soil profile exhibited marked differences between experimental plots. The soil water was predominantly held at a very shallow depth ( …

Relationship Of Visual And Quantitative Methods Of Grass Sward Development, R B. Mitchell, L E. Moser, K J. Moore

IGC Proceedings (1997-2023)

The objective of this study was to determine the relationship between visual and quantitative estimates of the morphological development of perennial grass swards. Pure stands of intermediate wheatgrass [Thinopyrum intermedium (Host) Barkw. & D.R. Dewey] and switchgrass (Panicum virgatum L.) were hand-clipped to ground level at 2-wk intervals in 1991 at Mead, NE, morphologically classified as mean stage count (MSC), and visually estimated for sward development. Visual estimations of sward development for both species were representative of quantitative measurements during vegetative growth. However, as sward development advanced to the elongation and heading stages, visual methods over-estimated the population …

Morphological Development Rates Of Perennial Forage Grasses, R B. Mitchell, L E. Moser, K J. Moore, D D. Redfearn

IGC Proceedings (1997-2023)

The objective of this study was to determine the rate of change in the morphological development of switchgrass (Panicum virgatum L.) and big bluestem (Andropogon gerardii Vitman). Pure stands of each species were sampled at weekly intervals in 1990 and 1991 at Mead, NE, and morphologically classified as mean stage count (MSC) and mean stage weight (MSW). Linear day of the year equations accounted for 94% of the variation in switchgrass MSC and MSW. Switchgrass MSC and MSW increased at an average rate of 0.0204 and 0.0234 units per day, respectively. Linear day of the year equations accounted …

Fertilizer Nitrogen And Morphogenetic Response In Avena Sativa And Lolium Multiflorum, F Lattanzi, M A. Marino, A Mazzanti

IGC Proceedings (1997-2023)

A field experiment was carried out at the EEA Balcarce, INTA, Argentina (37° 45’LS, 58° 18’LW) to determine whether Leaf Appearance Rate (LAR) was affected by N fertilization in Italian ryegrass (Lolium multiflorum Lam.) and forage oats (Avena sativa). N treatments (0, 50, 100, 150, 200 and 250 kg N ha-1) were applied in winter 1995, after a defoliation. Subsequently, number of leaves per tiller was determined on 45 labelled tillers in each treatment twice a week. LAR was calculated as the slope of the linear regression of number of leaves on thermal time (air temperature, base …