青藏高原区披碱草属种子功能性状研究

Study of Functional Traits of Elymus Seeds in the Qinghai-Tibetan Plateau Region

以采自青藏高原高寒草甸野生披碱草属种子(垂穗披碱草、麦宾草、老芒麦、圆柱披碱草、黑紫披碱草)为材料,对其形态特征、萌发特性、吸水率和电导率等功能性状进行测定,旨在揭示不同居群披碱草属种子部分功能性状间的异同,为该属优良种质资源的挖掘、选育和利用提供依据。结果表明,不同居群野生披碱草属种子具有典型的共性:内外稃呈披针形,不开裂,稃及小穗轴表面分布白色短毛;种子去稃后顶端具毛,腹面为纵沟,中央为明显凸起的脊。各居群种子的种长、种宽、种厚、芒长、单粒重、稃颜色以及种皮颜色等形态特征存在一定差异,且种子萌发特性、吸水率和电导率间亦具有明显差异。垂穗披碱草萌发特性最优;种子吸水48 h后,圆柱披碱草吸水率达最高,为63.80%;黑紫披碱草电导率较高,为179.55μs/(cm·g)。种宽与发芽势、发芽指数和活力指数之间呈正相关,与平均发芽时间之间为负相关,单粒重与发芽势、发芽指数和活力指数间呈正相关;种子发芽势、发芽指数和活力指数两两之间呈显著或极显著正相关,发芽势和发芽指数分别与平均发芽时间呈显著负相关。灰色关联度综合分析得出,垂穗披碱草种子综合特性表现最佳,重视其种质的采集、保存及利用具有生态学意义。

This study aimed to investigate the similarities and differences among certain functional traits of Elymus seeds from different populations,and to provide the basis for the exploration,breeding,and utilization of valuable genetic resources of this genus.Morphological characteristics,germination characteristics,water absorption,electrical conductivity,and other functional traits were measured inwild Elymus seeds(Elymus nutans,Elymus tangutorum,Elymus sibiricus,Elymus cylindricus,Elymus atratus.)collected from alpine meadows on the Qinghai-Tibet Plateau.The results showed that the wild Elymus seeds from different populations shared typical characteristics such as lanceolate palea and lemma,indehiscence,with short white hairs on the surface of the palea and rachilla.The seeds exhibiteda pical hairy after the removal of lemma,and ventral longitudinal grooves with a prominent central ridge.Differences were observed in morphological traits,including seed length,seed width,seed thickness,awn length,single seed weight,lemma and seed coat color,as well as in seed germination characteristics,water uptake and electrical conductivity.E.nutans exhibited the best germination characteristics,while E.cylindricus showed the highest water uptake rate of 63.80% after 48 hours.The electrical conductivity of E.atratus was the highest at 179.55μs/(cm·g).Seed width was positively correlated with germination potential,germination index,and vitality index,and negatively correlated with average germination time.Single grain weight was positively correlated with germination potential,germination index and vitality index.Furthermore,the germination potential,germination index and vitality index of seeds were significantly or extremely significantly positively correlated with each other.Finally,germination potential and germination index were negatively correlated with the average germination time.Comprehensively grey correlation analysis indicated that E.nutans seeds exhibited excellent characteristics,highlighting the ecological significance of collecting,conserving,and utilizing their genetic resources.