【作者】 王学敏；

【导师】 易津；

【作者基本信息】 内蒙古农业大学 ， 植物学， 2002， 硕士

【摘要】 本论文对驼绒藜属植物种子的生理学特性进行了研究，包括种子的萌发特性、幼苗的耐逆性、种子的营养成分、激素水平、分子生物学以及种子生产技术等内容，同时对种子的劣变机理进行了探讨。 驼绒藜属牧草种子萌发最适温度为25℃的恒温和15～25℃的变温；属非光敏种子；种子萌发需水量范围为4.05～6.95倍种子干重，不同材料间种子萌发最低需水量存在明显差异，其中华北驼绒藜萌发需水量最低(4.05倍种子重)；种子的吸水速率较快，一般为0.6～0.7g／h·g种子，7～8h达到饱和吸胀；在相同环境条件下，种子活力表现出种间、生态型间及株龄间的差异，华北驼绒藜各项生理指标均明显高于其它材料。该属种子萌发时有较强的耐旱性和耐盐性，且存在种间、生态型间及株龄间的差异。 驼绒藜属牧草种子在营养成分及激素含量上存在种间、生态型间及株龄间的差异，相关分析表明，种子含糖量及内源激素与种子活力相关性均不显著，种子氮、磷含量与种子活力有显著的相关性。适宜的田间管理措施可以明显提高华北驼绒藜种子的产量和质量，提高种子的生理活性。 同工酶和RAPD分析表明，该属植物种间及生态型间存在明显的同工酶和DNA多态性。生殖器官(种子)与营养器官(根、茎、叶)的同工酶差异显著。植物材料间RAPD变异大，遗传多样性丰富，聚类分析结果表明，形态差异较小，地理分布区域较近的材料亲缘关系较近，其结果与形态学的研究结果基本一致，可为驼绒藜属植物的系统研究提供分子水平上的依据。 对驼绒藜属植物种子短命和劣变原因的初步分析，认为是由遗传和环境两方面的原因所至：一是由于驼绒藜植物属于高数量低营养种子类型，种子自然寿命较短。二是由于种子发育过程中自然环境恶劣，造成种子营养不良，发育程度较差。三是由于贮藏条件不适宜；尤其是含水量较高，造成种子劣变加速。更多还原

【Abstract】 The thesis studied on the physiological characteristics of Ceratoides L . The contents were composed of the germination characteristics, the resistance of seed and seedling, the nutritive composition, the hormone content, the seed production and the molecular physiology, we studied the deterioration mechanism of seed as well.The proper germinating temperature of Ceratoides L seed is the constant temperature of 25 C and variable temperature of 15-25 C; The seed belongs to nonphotosentive one; The water requirement of germination ranged from 4.05 to 6.95 times of dry weight , and the minimum requirement existed obvious differences between materials ,in which C. arborescens requirement was the lowest (4. 05 time of seed dry weight);The seed quickly absorbed water during germination , The speed generally was 0. 6-0.7g/h.g seed and seed imbibtion was saturated after 7-8h. Under the same environmental condition, the physiological activity of seeds displaied differences between species , ecotypes or plant with different age. The physiological indexes of C.arborescens all obviously dominated other species. The seeds of Ceratoides L. had great power of drought resistance and salt resistance, meanwhile, there are great differences between species, ecotypes or plants with different age.The nutritive composition and hormone contents of seed existed differen- ces between Species, ecotypes or plants with different age. The correlation between sugar content and seed physiological activity was not obvious, while N,P contents and seed physiological activity obviously correlated. The appropriate measures could remarkably improve the. production and quality of seeds of Ceratoides L. in field .The analysis of isozyme and RAPD of seeds dedicate that there were abundant variations on isozyme and genomic DNA, there were also ecologi-cal multiplicity between species ,ecotypes or plants with differents age in Ceratoides L. There were obvious differences between reproductive organ (seed) and nutritive organs (root, stem and leaf). The result of cluster analysis showed that the materials with fewer morpholo- gical difference and nearer geographical distribution had nearer relationship. This result was in keeping with the result of morphology on the whole and could provided molecular basis for the systematic study of Ceratoides.L plants.The deterioration of seed was due to two reasons. That were genetic factor and environmental factor. First, the Ceratoides.L seed belongs to low nutrition seed and it’ s nature longetivity was short; second, because of the harsh environment during seed developing ,seeds were short of nutrition and the development were uncomplete; Third, because of the unsuitable storage condition, especially because the water contens was higher, the seed deteriorated rapidly.更多还原