Developmental and Structural Section
Weagle, Adam , Hildebrand, T.J. , Smith, H.G. .
The Affect of Solution pH on Plant (Helianthus annus L., Asteraceae).
Helianthus annuus (sunflower) is important to many economies, found in every soil type, and distributed across North America. As a crop, sunflowers grow in a variety of soil types and respond to nitrogen, phosphorous and potassium amendments. Optimum soil pH for sunflower growth has been recorded between 6.0 and 8.0, but more extreme values have not been examined. Additionally, differences in the anatomical structure of plants grown over a broad pH range have not been explored. Our study reports the morphological and anatomical changes that develop when sunflowers are grown in environments that differ in solution pH. The variant “Pacino Gold” was an ideal study organism because its dwarf size was manageable in the greenhouse. Plants were grown in a soilless mix for eight weeks. Three replicates of 12 specimens were included in each treatment that applied water solutions of seven pH values (4.5 – 9.5). Plant height, number of leaves, leaf length, and leaf wilt were recorded weekly. At the end of the growing period, stem width and total biomass were quantified. Regression and ANOVA analyses revealed significant effects on growth associated with various solutions. Solution pH affects were also investigated anatomically on randomly selected samples from three treatments (pH 4.5, 7.5, and 9.5). Slides of leaf petiole and root tip transverse sections were stained, photographed and internal structures measured. Data were collected on the areas of vascular bundles, leaf petiole, xylem, phloem, and cortex (excluding epidermis) tissue as well as the area of random vessel elements. Anatomical changes in structure were not significant within each treatment, but varied significantly among pH solutions and were most associated with vascular bundle area. Future studies that investigate the affect of solution pH on sunflower reproduction and fitness have the potential for agricultural and horticultural application.
Log in to add this item to your schedule
1 - 5918 South 571 East, Murray, Utah, 84107, USA
2 - Southern Utah University, Biology Department, Life Science 184b, 351 West University Boulevard, Cedar City, Utah, 84720, USA
3 - 14935 New Vista Place, Hacienda Heights, CA, 91745, USA
tissue area ratios.
Presentation Type: Poster:Posters for BSA Sections
Location: Event Tent/Cliff Lodge
Date: Monday, July 27th, 2009
Time: 5:30 PM