驼绒藜属牧草种苗耐盐性评价及生理基础研究

Assessment of Salt Resistance and Physiology Basis of Seed and Seedling of Ceratoides

对 7份驼绒藜属材料种子萌发及幼苗进行耐盐性研究。结果表明 ,种苗具有较高的耐盐性 ,在种间及种内生态型间存在差异 ,其中华北驼绒藜耐盐性最强 ,其次为华北驼绒藜科尔沁生态型 ,驼绒藜荒漠生态型和心叶驼绒藜耐盐性最弱。种苗的耐盐能力和种子的活力呈正相关 ,在恶劣生境条件下形成的种子活力较低 ,种苗的耐盐力也较低 ;种苗耐盐半致死浓度与种子活力 3项指标呈显著或极显著正相关 (r=0 .82 * 、0 .93* * 、0 .90 * * )。而盐性生理基础的研究结果表明 ,种子耐盐性的指标与种子含氮量呈极显著正相关 (r=0 .88* *、0 .90 * * ) ,与种子含磷量呈正相关 (r=0 .77、0 .6 8) ,与含糖量相关性较小 (r=- 0 .33～ 0 .5 5 )。初步认为种子耐盐半致死浓度、种子活力指数和含氮量可以作为种子耐盐性评价和选育的生理指标。

A study on the seven Ceratoides (Tourn.) Gagnebin seed samples for their germinating ability and seedling salt resistance shows that different seedling species and ecotypes bear with different degrees of salt concentration. C.arborescens boasts the strongest salt tolerance, C.arborescens of the keerqin ecotype comes second, while C.latens of the cold desert ecotype and C.ewersmanniana are the least salt tolerant. Ceratoides seed and seedling's salt tolerance is in proportion with the seed vigour. In general, seeds that are produced in adverse conditions exhibit lower vigour, and the seedlings lack salt tolerance. The seedlings' ability of enduring an environment of half lethal salt concentration is significantly related to the seed germinating rate, the germination index,and the seed vigour index (r=0.82 *,0.93 ** ,0.90 ** respectively).Study on the physiological basis of the seedling salt resistance shows that the seed nitrogen content is in direct proportion both with the seedling salt resistance capacity(r=0.88 *,0.90 ** ), and its phosphorus content (r=0.77,0.68),though not closely related to the seed carbohydrate content (r= -0.33～ 0.55). It is summarized that the seedling's tolerance of half lethal salt concentration, the seed vigour index ,and the seed nitrogen content could be regarded as the physiological index for assessing the level of the seed salt tolerance and whether it be selected for breeding.