油蒿与中国和以色列沙漠中的两种蒿属植物种子萌发策略的比较(英文)

Comparison of Germination Strategies of Artemisia ordosica with Its Two Congeners from Deserts of China and Israel

油蒿 (ArtemisiaordosicaKrasch .)是中国戈壁荒漠的固定沙丘上分布的优势种灌木 ,属蒙古植被地理分布区成分。油蒿的瘦果在光下萌发 ,萌发在暗中受到抑制 ,光是调节其在沙土不同深度萌发的限制因素。瘦果在春天或秋天萌发 ,适宜温度为 2 0℃。瘦果的粘液物质能吸收大量水分 ,具有重要的生态功能。不同浓度的盐溶液能影响瘦果的萌发。土壤湿度也是调节瘦果在沙中萌发的因素。尽管油蒿、白沙蒿 (A .sphaerocephalaKrasch .)与A .monospermaDelile.生长于不同的气候环境中 ,但其瘦果的萌发对光照、瘦果在沙层中的位置、土壤湿度有着相似的反应。不同沙层深度的出苗率依不同植物、不同温度、穿过不同沙层深度的光强以及沙土湿度的不同而表现出了差异。沙漠环境可能对

Artemisia ordosica Krasch. is a dominant shrub occurring mainly on stable sand dunes in the Gobi Desert of China, in the Mongolian phytogeographic region. Achenes of A. ordosica germinate in light but poorly in dark and light is the limiting factor regulating the achene germination in sand depth. Achenes germinate in spring or autumn with an optimal temperature of 20 ℃. Achene mucilage can absorb large amounts of water and has important ecological function. Salt concentrations and sand moisture may regulate achene germination in sand. A. ordosica, A. sphaerocephala Krasch. and A. monosperma Delile. from different climates have similar responses to light, the underground location of achene, and sand moisture. Percentage of seedling emergence from different levels of sand depth is depends on the specific, temperature and intensity of light penetrating through the sand depths, as well as on sand moisture. The desert sand habitat seems to have had a dominant influence on the evolution of the germination strategies of these 3 Artemisia species.