Department of Plant Biology, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon.
Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
Sci Rep. 2024 Jul 23;14(1):16995. doi: 10.1038/s41598-024-66018-9.
Cylicomorpha solmsii (Urb.) Urb (Caricaceae) is a wild relative of domesticated Carica papaya native to the humid tropical forest of Cameroon. C. solmsii is becoming extinct due to rapid urbanization of its habitat. There is currently no restoration planning, no available data on seed germination, details on morphological description and fruit phenology. We investigated the effects of light and soil on seed germination, updated its morphological description and provided cues of its fruit phenology. In two series of experiments, a germination test was first conducted under light and dark conditions with three seed pre-treatments (scarification, drying and cold). Secondly, pre-treated seeds were sown in native soils of C. solmsii habitat collected at Eloumden I and II, two ex-situ and mixtures soil with sand. Qualitative and quantitative data were collected on different part of the plant and analyzed using R package version 4.3.2. Our findings showed that C. solmsii seeds can germinate only under light. The seeds manifested a physiological embryonic dormancy. The native soils showed the highest germination percentage and seedling establishment. The dioicy of C. solmsii was clearly described with incomplete staminate and pistillate unisexual flower whorls. C. solmsii was observed to produce fruits throughout the year at varying intensity. This information is a vital cue to species restoration and policy makers towards C. solmsii conservation.
环果桑（Cylicomorpha solmsii）（榕桑科）是原产于喀麦隆潮湿热带森林的木瓜（Carica papaya）的野生近缘种。由于其栖息地的快速城市化，环果桑正面临灭绝。目前没有恢复规划，也没有关于种子萌发、形态描述和果实物候学的可用数据。我们研究了光照和土壤对种子萌发的影响，更新了它的形态描述，并提供了其果实物候学的线索。在两个系列的实验中，首先在光照和黑暗条件下进行了萌发测试，使用了三种种子预处理（刻痕、干燥和冷藏）。其次，将预处理后的种子播种在环果桑栖息地的原生土壤中，这些土壤分别取自 Eloumden I 和 II，这两个是种子的原地保存地，另外还有与沙子混合的土壤。在植物的不同部位收集定性和定量数据，并使用 R 包版本 4.3.2 进行分析。我们的研究结果表明，环果桑种子只能在光照下萌发。种子表现出生理上的胚胎休眠。原生土壤表现出最高的发芽率和幼苗建立率。环果桑的雌雄异株被清楚地描述为不完全的雄花和雌花轮生。环果桑全年都在不同程度地结果。这些信息对于物种恢复和政策制定者保护环果桑具有重要意义。
