环境因子对云南扁穗雀麦种子萌发和出苗的影响  

Environmental factors affecting seed germination of prairie grass(Bromus willdenowii)in Yunnan Province

作　　者：张敏[1] NIPAPAN Kanjana 李铷 傅杨[1] 汤东生[1] ZHANG Min;NIPAPAN Kanjana;LI Ru;FU Yang;TANG Dong-sheng(State Key Laboratory for Bio-resource Protection and Utilization in Yunnan,Yunnan Agricultural University,Kunming 650201,China)

机构地区：[1]云南农业大学云南生物资源保护与利用国家重点实验室,云南昆明650201

出　　处：《草业学报》2021年第12期143-151,共9页Acta Prataculturae Sinica

基　　金：国家自然科学基金项目(31660555);云南省重点研发计划项目(2016RA007)资助。

摘　　要：扁穗雀麦是近年由牧场逃逸至农田的恶性入侵杂草。为了解入侵和生态适应性规律,通过室内试验测定了温度、湿度、深度、pH、盐和渗透势对扁穗雀麦种子萌发的影响。结果表明,30/20℃的变温处理下种子萌发率最高,达到92.1%;随着日平均温度的降低种子萌发率逐渐降低;日平均温度接近10℃种子几乎不萌发。在pH 5~10的环境条件下,种子萌发率均能达到90%,弱酸和弱碱处理的种子萌发率显著高于中性处理。低于20 mmol·L^(-1)的NaCl处理与对照无显著差异,160 mmol·L^(-1)的处理种子萌发率仍可达到85%以上。-0.1 MPa的渗透势下种子萌发率最高,渗透势高于-0.2 MPa的处理种子萌发率与对照无显著差异,-0.4 MPa处理种子的萌发率仍高于80%。在60%相对湿度的土壤中,种子的萌发率和萌发势均最高。播种于土表的种子萌发势和萌发率均最高,播种深度达到10 cm时,种子几乎不萌发。由此可见,扁穗雀麦种子萌发对环境条件的生态适合度高,因此在多数区域气候温暖干旱的云南具有入侵广阔生境的可能性。Prairie grass(Bromus willdenowii)is a serious invasive weed escaped from sown pastures to wild grassland.To investigate factors contributing to invasiveness and ecological adaptability of prairie grass,the effects of temperature,humidity,seed burial depth,pH,salinity and osmotic potential on seed germination and emergence were examined in the laboratory.Among temperature treatments tested,it was found that the seed germination percentage was highest(92.1%)in an alternating temperature regime of 30/20°C(day/night).Seed germination percentage gradually decreased with decline in daily average temperature declined.There was nearly no germination when daily average temperature was close to or below 10°C.Germination rates of seeds incubated in the pH range from 5 to 10 were all above 90%.Germination results of seeds incubated in weakly acidic or weakly alkaline conditions were significantly higher than those incubated in neutral pH.Germination rates of seeds incubated in≤20 mmol·L^(-1) NaCl were similar to those of control.Germination was above 85%for seed incubated in 160 mmol·L^(-1) NaCl.The optimum osmotic potential for seed germination was-0.1 MPa.Germination rates of seeds incubated at osmotic potentials lower than-0.2 MPa were not significantly less than those of controls.Germination at an osmotic potential of-0.4 MPa was above 80%.The optimum soil relative humidity for seed germination rate and germination potential was 60%.Germination of seeds placed on the soil surface was higher than for any other burial depth.Seeds sown deeper than 10 cm did not germinate.These results indicate that seed germination of prairie grass occurs freely over a wide range of conditions,conferring a high ecological fitness.Thus,prairie grass has a high potential to invade large areas of Yunnan where the prevailing climate is warm and dry periods of below average rainfall can occur.

关 键 词：扁穗雀麦 种子萌发 环境因子 生态适应性 

分 类 号：S543.8[农业科学—作物学]