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Morphological and germination traits of Garcinia xanthochymus seeds with their cytological basis and ecological adaptation
| First Author: |
Yang, Lan |
| Abstract: |
Garcinia xanthochymus is a climax tree species growing in the Xishuangbanna tropical rainforests, which possesses a unique adaptation mechanism to the tropical monsoon climate, i.e., its seeds mature at the end of the rainy season and shed, mostly do not germinate until next rainy season, distinctly differing from most other climax species there. This study investigated the morphological structure, desiccation tolerance, and germination characteristics of G. xanthochymus seeds to understand their cytological basis and ecological adaptation. It was found that G. xanthochymus seeds germinate when incubated at temperatures between 20 and 35 degrees C, with a thermal optimum of 30 degrees C, but have a short period of dormancy (> 40 days even at 30 degrees C). The seeds were intolerant to desiccation, and completely lost viability when desiccated to 25% miosture content (fresh weight basis), exhibiting typical recalcitrant seed traits. However, they also possessed strong desiccation resistance, maintaining approximately 33% misture content and 50% viability even after 20 days of silica gel drying. Until germination, G. xanthochymus seeds did not exhibit visible structural differentiation. They are composed of a cluster of uniformly shaped, shallowly differentiated parenchymal cells possessing embryonic and storage functions. Thus, they germinate totipotently and can regenerate into seedlings even after being subjected to various cutting, which protects them from animal grazing. This explains how G. xanthochymus seeds withstand biotic and abiotic stresses during the dry season in Xishuangbanna, meanwhile implys that G. xanthochymus is more dependent on the forest environment and more sensitive to habitat changes. |
| Contact the author: |
Wen, B; Chen, LG |
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| Impact Factor: |
1.7 |
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| PubYear: |
2024 |
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| Publication Name: |
PLANT ECOLOGY |
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