Permalink : http://hdl.handle.net/2115/49969

KEYWORDS : Populus euphratica;water content;soil types;sexual reproduction;seed germination;Chinese Arid region

Both of water and soil are the most essential factors for the establishment and growth of plants. This study firstly investigated the sexual reproduction of two stages of Populus euphratica, seed germination and seedling growth. We focused on the various screening effects of nine combinations (three moisture gradients × three normal soil types) on seed and seedling of Populus euphratica. With the water content rising (from 10% to 20%), seeds and seedlings on all the soil substrates showed higher germination rate, germination speed or germination index and survival rate and better growth conditions, respectively. Besides, higher moisture could guarantee seeds to germinate 4-8 hours earlier and greater germination rate. In the comparison among the soil substrates, seeds and seedlings favored the lower-salinity and richer-nutrient river bank soil, which impelled a 4-hour earlier and higher germination peak period and ensured the greatest seedling quality. Therefore, the combination of '20%, river bank soil' was the most suitable condition for P. euphratica seeds and seedlings, which highly consisted with its riparian sexual regeneration phenomenon. Finally, by analyzing the unsteady river flow and river bank status, we concluded that the reason for the failure of P. euphratica sexual reproduction was that the time and quantity of water supply should be adjusted to create more suitable and stable habitat for P. euphratica seeds and seedlings.