Abstract
Plants ofChrysanthemum cv. Lillian Hoek were treated with a paclobutrazol (PBZ) soil drench and histologically examined after 3 months. PBZ application resulted in thicker leaves, reduced stem diameter, and roots with an increased diameter and an unusual segmented appearance. Increased leaf thickness was partly due to an additional layer of palisade mesophyll, although individual palisade cells were shorter, of smaller diameter, and more tightly packed. Spongy mesophyll depth was also greater and the individual cells were more rounded and the volume of intercellular space was reduced. The narrower stems had an increased development of secondary xylem, but had a marked reduction in the number of sclerenchyma bundle caps. Increased root diameter was due to an increase in the number of rows and diameter of cortical cells. In PBZ-treated plants, root cortical cell length was 50–70% less than in untreated plants, and this reduction appeared to be associated with the segmentation of the roots. PBZ inhibited secondary vascular development in the roots. This study is similar to other relevant studies in recording thicker leaves and roots with PBZ application; however, many of the underlying anatomical changes described above have not been previously reported.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Aguirre R, Blanco A (1990) Patterns of histological differentiation induced by paclobutrazol and GA3 in peach shoots. In: Proc. 23rd Int Hort Cong Firenze, Italy. Poster 4233
Barnes AM, Walser RH, Davis TD (1989) Anatomy ofZea mays andGlycine max seedlings treated with triazole plant growth regulators. Biol Plant 31:370–375
Bausher MG, Yelenosky G (1987) Morphological changes inCitrus associated with relatively high concentrations of paclobutrazol. J Plant Growth Regul 5:139–147
Dalziel J, Lawrence DK (1984) Biochemical and biological effects of kaurene oxidase inhibitors, such as paclobutrazol. Br Plant Growth Regul Group, Monograph 11, 43–57
Hawkins AF, Hughes HK, Hart CA (1985) Effects of the growth regulator, paclobutrazol, on structure and photosynthesis of soybean leaves. Br Plant Growth Regul Group, Monograph 12, 127–142
Jaggard KW, Lawrence DK, Biscoe PV (1982) An understanding of crop physiology in assessing a plant growth regulator on sugar beet. In: McLaren JS (ed) Chemical manipulation of crop growth and development. Butterworth, London, pp 139–150
McDaniel GL, Graham ET, Maleug KR (1990) Alteration of poinsettia stem anatomy by growth-retarding chemicals. HortScience 25:433–435
Privé J-P, Elfving DC, Proctor JTA (1989) Paclobutrazol, gibberellin, and cytokinin effects on growth, development, and histology of apple pedicels and fruits. J Am Soc Hort Sci 114:273–278
Sankhla N, Davis TD, Jolley VD, Upadhyaya A (1986) Effects of paclobutrazol on the development of iron chlorosis in soybeans. J Plant Nut 9:923–934
Wample RL, Schnabel B, Ahmedullah M (1987) Leaf area and conductance, internode length, and root structure of five cultivars ofVitis vinifera treated with paclobutrazol. Am J Enol Vitic 38:255–259
Williamson JG, Coston DC, Grimes LW (1986) Growth responses of peach roots and shoots to soil and foliar-applied paclobutrazol. HortScience 21:1001–1003
Wood BW (1984) Influence of paclobutrazol on selected growth and chemical characteristics of young pecan seedlings. HortScience 19:837–839
Ziv M, Yogev T, Krebs O (1986) Effects of paclobutrazol and chlormequat on growth pattern and shoot proliferation of normal and variantAechmea faciata Baker plant regeneratedin vitro. Israel J Bot 35:175–182A0443017 00002 CS-SPJRNPDF [HEADSUP]
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Burrows, G.E., Boag, T.S. & Stewart, W.P. Changes in leaf, stem, and root anatomy of Chrysanthemum cv. Lillian Hoek following paclobutrazol application. J Plant Growth Regul 11, 189–194 (1992). https://doi.org/10.1007/BF02115476
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02115476