Seed Germination And Seed Priming In Arid Region Wild Xerophytes

The ecological environment of arid and semi-arid region is fragile and sensitive,and xerophytes is an important part of desert vegetation.Wild xerophytes planting is an effective measure to control desertification,reduce soil and water loss and restore vegetation.In this research,ten xerophytes from Inner Mongolia were selected:Pugionium cornutum,Salsola passerina,Ammopiptanthus mongolicus,Sophora alopecuroide,Amygdalus mongolica,Reaumuria songarica,Agriophyllum squarrosum,Zygophyllum xanthoxylun,Corethrodendron scoparium and Caragana korshinskii seeds were used as research objects to describe the morphological characteristics and study the physiological characteristics.The seeds with dormancy characteristics were treated by breaking dormancy.Different temperature gradients were set to research the optimum germination temperature of seeds.In order to improve germination speed,the seeds were treated with priming.7 groups of water priming,300mg/LGA₃priming,400mg/L GA₃priming,500mg/L GA₃priming,20%PEG priming,30%PEG priming and 40%PEG priming were set.The effects of different priming modes on germination rate,germination time and germination potential of seeds were researched,and the optimal priming mode was selected through comparison,providing theoretical basis for the propagation and utilization of xerophytes.The main results of this study are as follows:（1）There is physical dormancy in Amygdalus mongolica,Corethrodendron scoparium and Sophora alopecuroides,which can be effectively lifted by mechanical removal of endocarp,pods and seed coats.Physiological dormancy existed in sapon seeds,and acupuncture and 400mg/L GA3 initiation could effectively break dormancy.The main reason for the germination rate of Caroxylon passerinum is less than 50%because there are no seeds in a large number of fruits and the seed development rate is low.Other test seeds did not lie dormant.（2）The optimal germination temperature for Agriophyllum squarrosum and Caroxylon passerinum is 15°C.The optimal germination temperature for Reaumuria songarica is 20°C.The optimal germination temperature for Caragana korshinskii,Ammopiptanthus mongolicus,Pugionium cornutum and Zygophyllum xanthoxylun is25°C.The suitable germination temperature of Mongolian amygdala and Astragalus chinensis is 20°C and 25°C.The optimal germination temperature for Sophora alopecuroides is 25°C and 30°C.（3）Different priming types,priming solution concentration,priming duration,priming temperature,plant species and seed quality will lead to differences in priming effect.Priming treatment can break seed dormancy to varying degrees,improve seed germination rate,accelerate seed germination or inhibit seed germination.Water-initiated treatment had the effect of promoting seed germination and accelerating seed germination on Pugionium cornutum and Agriophyllum squarrosum.It had no significant effect on the germination rate of Zygophyllum xanthoxylun and Reaumuria songarica seeds,and accelerated seed germination.There was no significant effect on the germination of Caroxylon passerinum and（needled）Agriophyllum squarrosum.PEG triggered accelerated seed germination of Pugionium cornutum,Caroxylon passerinum and Agriophyllum squarrosum seeds,and increased germination rate.There was no significant effect on the germination rate of Zygophyllum xanthoxylun and Reaumuria songarica,and the germination rate was accelerated.There was no significant change in germination rate and germination index after PEG was initiated.GA₃induced the effect of increasing germination rate and accelerating germination on Pugionium cornutum,Caroxylon passerinum and Agriophyllum squarrosum.There was no significant effect on the germination rate of Zygophyllum xanthoxylun,and the germination index was significantly improved.400mg/L GA₃was the best treatment to improve the germination rate and germination index of Caroxylon passerinum and Agriophyllum squarrosum.500mg/L GA₃improved the germination rate and germination index of Pugionium cornutum best.Each priming treatment had no significant effect on the germination rate of Reaumuria songarica seeds,and the 300mg/L GA₃priming treatment had the most significant effect on the germination index of Reaumuria songarica seeds.PEG initiation and 500mg/L GA₃increased the germination index of Zygophyllum xanthoxylun seeds.In this research,the effects of water-priming,PEG-priming,and GA₃-priming on seed germination and dormancy characteristics of wild xerophytes were preliminarily clarified,and the most suitable initiation methods for each plant were explored.The research results can be used to guide the efficient planting,expansion and utilization of wild xerophytes.It is conducive to further promoting the application of wild xerophytes in ecological environment restoration,urban landscaping and medical and food development.