ISHS Acta Horticulturae 404: International Symposium on Cultivar Improvement of Horticultural Crops. Part 3: Flowers
SHORTENING HYBRIDIZATION BREEDING CYCLE OF ROSE-A STUDY ON MECHANISMS CONTROLLING ACHENE DORMANCY |
| Authors: | J. Bo, D. Huiru, Y. Xiaohan |
| Keywords: | Rosa hybrida, seed dormancy, breeding, abscisic acid |
| Abstract:
Delayed germination or achene dormancy makes hybridization breeding a lengthy process in rose (Rosa hybrida). In an effort to slove this problem, we have studied the mechanisms controlling achene dormancy in cv. Crimson Glory. Anatomical observations and surgical experiments conducted under aseptic conditions revealed that the embryo is not dormant, and the pericarp is tough and impermeable, preventing embryo germination to a certain extent. However, softening of pericarp by hydrochloric acid failed to cause achenes to germinate, implying that the physical restriction imposed by pericarp is not the exclusive cause of dormancy. Extracts of pericarp markedly inhibited germination in a Chinese cabbage bioassay. High-performance liquid chromatography analysis showed that the endogenous abscisic acid (ABC) levels in pericarp and testa are both relatively high (0.85 and 1.38 ug/g fresh wt, respectively), whereas the embryo containing a very low level of ABA (0.18 ug/g fresh wt). The results of this study indicate that the dormancy of achenes of cv. Crimson Glory is controlled by ABA in pericarp and testa in combination with physical restiction imposed by pericarp. A method for overcoming achene dormancy is recommended. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
