【作者】 韩建欣；

【导师】 魏岩；

【作者基本信息】 新疆农业大学 ， 环境科学， 2011， 硕士

【摘要】 论文通过对高枝假木贼(Anabasis elatior)的胎生萌发物候、种子萌发特性、耐盐性、幼苗耐干燥特性以及胎生苗的形成进行观察研究,并结合环境因子探讨其对准噶尔荒漠极端环境的响应对策,得出如下结论：(1)高枝假木贼具有胎生繁殖现象。其果实于10月成熟后不脱落,冬季被积雪覆盖。于次年早春积雪融化时(3月上旬～4月上旬)种子在株上萌发形成胎生幼苗。胎生萌发时,胚根首先突破种皮,下胚轴快速生长形成棒状胎生幼苗,长度为1～7 cm。胎生发生阶段空气最高温度为0～15℃,相对湿度为50%～60%。(2)高枝假木贼种子长4.175+0.132 mm,宽3.146+0.109 mm,质量3.727±0.137 mg;种子具有快速萌发特性,在30/15、25/15、20/10、15/5℃下,种子遇水6～7 h开始萌发。(3)高枝假木贼种子的萌发率随盐分浓度的增高而降低,在大于1.2 mol/L的NaCl溶液中的萌发受到抑制。将在盐溶液中处理后未萌发的种子转移至蒸馏水后,萌发恢复率较低,表明NaCl处理后的部分种子永久地失去萌发活力。(4)高枝假木贼的幼苗具有忍受干燥并在下次水合后能够恢复生长的能力。幼苗的长度和干燥时间影响幼苗的恢复生长率。长度在0～1 cm的幼苗通过14 d的干燥,有部分幼苗复水后能继续生长。长度在4～5 cm的幼苗干燥3 d后,复水未能继续生长。高枝假木贼的胎生繁殖现象是对荒漠严酷环境的一种特殊适应方式,在一定程度上为种群的传播、扩散和数量的增加提供了新的途径。更多还原

【Abstract】 In this paper, the vivipary germination phenology, characteristics of germination, salt stress, seedling desiccation tolerance of Anabasis elatior was observed, viviparous seedling characteristic of germination and its ecological adaptation. Combining with environment factors, survival strategies strategies in the extreme environment of Junggar desert were discussed. The main results were as follow:(1)Anabasis elatior has viviparous propagation phenomenon. Its fruits matured in October and still adhered to the mother plant. Anabasis elatior were covered by snow over this period. The seeds germinated on the mother plants and developed into viviparous seedlings during in early spring when snow melted (i.e. from early March to early April) that the maximum air temperature was maintained at 0～15℃and the relative humidity was 50%～60%. When vivipary occurred, the radicle emerged through the pericarp and the hypocotyl grew rapidly, developing into viviparous seedlings 1-7 cm in length.(2)Anabasis elatior seed was 4.175±0.132 mm length,3.146±0.109 mm width and 3.727±0.137 mg weight; Its seeds have rapid germination characters and could germinate 6-7 h after imbibition at 30/15. 25/15,20/10 and 15/5℃under a 12 h photoperiod.(3)The percentage of germination of Anabasis elatior will decrease with the salinity concentration increasing, the germination will be inhibited when the concentration of NaCl solution exceeds 1.2 mol/L. Seeds that were incubated in NaCl solution for 15 d recovered after being transferred to distilled water and all the percentage of recovery was low, the result shows that a portion of the NaCl-treated seeds may lose their germination ability.(4)Viviparous seedlings dispersed from their mother plant naturally. The seedlings have the ability to tolerate drought stress and to recover after rehydration. Seedling survival rates were influenced by seedling length at the time of dispersal and duration of dehydration. Seedlings length from 0 to 1 cm were able to rehydrate and recover after drought stress for 14 d, whereas 4-5 cm long seedlings did not recover.Anabasis elatior’s viviparous propagation phenomenon is a special adaptive strategy to harsh environment. To some extent, it provides a new way for population renewal and reproduction.更多还原