Journal
SOUTH AFRICAN JOURNAL OF BOTANY
Volume 75, Issue 3, Pages 537-545Publisher
ELSEVIER
DOI: 10.1016/j.sajb.2009.05.001
Keywords
Dormancy; Garhadiolus papposus; Germination; Junggar Desert; Trimorphic achenes
Categories
Funding
- Research and Development of High Technology of Xinjiang Uygur Autonomous Region, China [200810102]
- Chinese Ministry of Science and Technology [2005DKA21006]
- National Natural Science Foundation of China [90302004]
Ask authors/readers for more resources
Dormancy and germination of dimorphic achenes have been compared within and between numerous species of Asteraceae, whereas only a few such comparisons have been made with trimorphic achenes. Garhadiolus papposus is an annual ephemeral species of disturbed desert habitats that produces three kinds of achenes that differ in size, morphology, pappus development and germination requirements. Fresh central achenes germinated to 10-21% in light at 15/2 and 20/10 degrees C, while intermediate and peripheral achenes germinated to <5%. Germination was enhanced by excising the embryo in peripheral but not in intermediate achenes. For peripheral and intermediate achenes, pericarps and/or phyllaries did not inhibit germination of isolated embryos, indicating that water-soluble germination inhibitors were not present in these structures. For central and intermediate achenes, germination percentage increased with duration of dry storage at room temperature. Darkness decreased germination of central and intermediate achenes, while peripheral ones, which were viable, did not germinate at any condition. These data show that 1) the three morphs differ in germination requirements, and 2) difference in germination may be caused by low growth potential of the embryo and mechanical resistance (to embryo growth) of the thick pericarp and/or lignified phyllary. (C) 2009 SAAB. Published by Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available