环境因子对奇异虉草和小子虉草种子萌发的影响

Influence of Environmental Factors on Seed Germination of Phalaris paradoxa and Phalaris minor

在室内条件下考察了环境因子温度、pH、盐分、土壤含水量以及种子埋深对外来入侵植物奇异虉草和小子虉草种子萌发和幼苗生长的影响,并与小麦进行对比研究.结果显示;(1)当温度为5℃、NaCl浓度为0.25 mol/L以及种子埋藏深度达到30 mm时,奇异虉草和小子虉草的种子完全不能萌发,而同等条件下小麦种子的发芽率分别依次为89.33%、53.33%和95.00%.(2)在pH 4.0～10.0和土壤含水量10.0%～25.0%条件下,奇异虉草和小子虉草的种子均能萌发;但pH在4.0和10.0以及土壤含水量低于15%时,其发芽率受到显著抑制;当土壤含水量为10%时奇异虉草和小子虉草的种子发芽率分别为19.33%和16.67%,而小麦种子的萌发完全受到抑制.(3)奇异虉草和小子虉草的幼苗最适生长环境为,温度25℃～30℃、pH为6.0～9.0、NaCl浓度0～0.05 mol/L以及种子埋藏深度为0～5 mm.研究表明温度、盐分和种子埋藏深度是影响奇异虉草和小子虉草种子萌发的关键因素,而偏碱性环境更有利于其种子萌发,其种子萌发对干旱胁迫的耐受性强于小麦.

To explore the effects of environmental factors on seed germination and seedling growth of Phalaris paradoxa L.and Phalaris minor Retz.,we conducted some experiments of temperature,pH,salt stress,soil water content,and burial depth in comparison to wheat in laboratory.The results showed that：（1）Seed germination of P.paradoxa L.and P.minor Retz.was obviously different to wheat,and significantly affected by temperature,salt stress and burial depth.The germination rates of wheat under conditions of temperature 5℃,NaCl concentration 0.25 mol/L and burial depth 30 mm were 89.33%,53.33% and 95.00%,respectively;however,seedlings of P.paradoxa L.and P.minor Retz.were not emerged at the same conditions.（2）The seeds of P.paradoxa L.and P.minor Retz.had some resistance to pH stress and drought stress.Over 60% seeds of P.paradoxa L.and P.minor Retz.were germinated within pH 5.0～10.0 and soil water content 12.5% exceeded,but their germination rates were significantly inhibited when pH was 4.0 and soil water content was 10%.As soil water content was 10%,germination rates of P.paradoxa L.,P.minor Retz.and wheat were 19.33%,16.67% and 0%,respectively.（3）The seedling growth of P.paradoxa L.and P.minor Retz.was markedly influenced by environmental factors,in which temperature 25℃～30℃,pH 6.0～9.0,NaCl concentration under 0.05 mol/L,and burial depth less 5 mm were the optimum environmental factors.Environmental factors play one of the most important roles in seed germination and seedling growth of P.paradoxa L.and P.minor Retz.,and the temperature,salt stress and burial depth are identified as the key environmental factors.