首页|14种青藏高原草本植物的萌发特征对不同温度与水势的响应

14种青藏高原草本植物的萌发特征对不同温度与水势的响应

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随着全球气候不断变暖,青藏高原地区生态环境十分脆弱。研究这一区域温度和水分条件对野生牧草草种萌发活动的影响并以此为依据筛选适宜作为生态恢复的草种是稳定和恢复生态屏障功能的基础条件。通过PEG-6000调节渗透势模拟土壤干旱情况同时用10和20 ℃分别模拟青藏高原春季和夏季温度,研究14种青藏高原乡土草本植物在不同温度和水势下的萌发行为。结果表明:供试植物萌发策略具有多样化,大部分植物在不同温度和水势下萌发策略表现在发芽率增减的同时伴随萌发时间和萌发速率指数的变化且变化程度不一。有50%的植物(7种)在萌发时间上变化显著(P<0。05),在发芽率和萌发速率指数上呈弱响应,28。6%的植物(4种)三者的变幅都较大。个别植物表现不同,木根香青(Anaphalis xylorhiza)显著表现在发芽率和萌发时间上,劲直黄耆(Astragalus strictus)三者都呈弱响应,藏西蝇子草(Silene moorcroftiana)表现为发芽率和萌发时间较敏感。整体上植物种子在20 ℃时发芽率和萌发速率明显升高,随水势的增高而有所提高,较水势而言温度对萌发率的作用更显著,12种植物种子20 ℃萌发时间显著缩短8~10d。不同科植物对水热变化响应不同,供试植物中菊科、石竹科植物萌发表现较好。多数植物可在青藏高原地区夏季水分条件较好时作为建植草种进行生态恢复工作,藏沙嵩(Artemisia wellbyi)也可在夏季建植,藏西蝇子草、矮火绒草(Leontopodium nanum)、木根香青可在春季作为建植草种。
Germination test for 14 plants under different temperature and water potential conditions on the Qinghai-Tibet Plateau
With the continuous warming of the global climate,the ecological environment of the Qinghai-Tibet Plateau is highly fragile.Studying the effects of temperature and water conditions on the germination activities of wild herbage species in this region and selecting suitable grass species for ecological restoration based on these conditions is vital for stabilizing and restoring ecological barrier function.The PEG-6000 osmotic potential was used to simulate soil drought conditions,and the spring and summer temperature conditions were simulated at 10 ℃ and 20 ℃,respectively.The germination behavior of 14 native herbs on the Tibetan Plateau was studied under different temperature and water potentials.The results showed that the germination strategies of the plants tested were diversified.Most of the plants under different temperature and water potential showed that the germination rate increased or decreased along with the germination time and germination rate.50%of the plants,comprising seven species,had significant germination time and weak responses in terms of their germination rate at the 0.05 level.28.6%of the plants,comprising four species,showed considerable variation in the three.The germination rate index and germination time of Anaphalis xylorhiza were significantly different in individual plants.Astragalus strictus showed a weak response and Silene moorcroftiana had an increased germination rate index.Overall,the germination rate and germination rate of plant seeds increased significantly at 20 ℃,and increased with increasing water potential.The effect of temperature on germination rate was more significant than that of water potential.The germination time of 12 plant seeds at 20 ℃ was significantly shortened by 8~10 d.The plants of different families had different responses to the change in water and heat,and the plants from Compositae and Dianthus had a higher germination rate.Most of the plants could be used as established grasses for ecological restoration on the Qinghai-Tibet Plateau in summer when the moisture conditions are more suitable.Tibetan Artemisia wellbyi can also be established in summer,and S.moorcroftiana,Leontopodium nanum,and A.xylorhiza can be used as established grasses in spring.

hydrothermal conditionhigh cold regiongrassseed germinationnative plant

安雅静、王佳、杨筱倩、冀盼盼、赵雯萱、王向涛、张志新

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西北农林科技大学草业与草原学院,陕西杨凌 712100

西藏农牧学院动物科学学院,西藏林芝 860000

水热状况 高寒地区 草地 种子萌发 乡土植物

西北农林科技大学-西藏农牧学院联合基金

2452020044

2024

草业科学
中国草原学会 兰州大学草地农业科技学院

草业科学

CSTPCD北大核心
影响因子:0.854
ISSN:1001-0629
年,卷(期):2024.41(5)