不同酸碱条件下内生真菌对三种禾草种子萌发的影响  

Effects of Neotyphodium endophytes on seed germination of three grass species under different pH conditions

作　　者：彭清青[1] 李春杰[1] 宋梅玲[1] 梁莹[1] 南志标[1] 

机构地区：[1]草地农业系统国家重点实验室兰州大学草地农业科技学院,甘肃兰州730020

出　　处：《草业学报》2011年第5期72-78,共7页Acta Prataculturae Sinica

基　　金：国家重点基础研究973项目(2007CB108902);国家科技支撑项目(2008BADB3B05);国家自然科学基金(30771531);教育部新世纪优秀人才支持计划(NCET-08-0256)资助

摘　　要：内生真菌可以通过提高禾草种子在干旱、盐胁迫等逆境条件下的萌发和促进植株生长而提高宿主的竞争力。本试验在pH为4～11的8个酸碱梯度下,对带菌(E+)与不带菌(E-)Neotyphodium属内生真菌的醉马草、中华羊茅和野大麦的萌发进行了研究,旨在探讨不同酸碱条件下内生真菌对禾草种子萌发的影响。结果表明,弱酸至强碱胁迫(pH为6～11)下,内生真菌显著提高醉马草种子发芽势;酸胁迫(pH为4～5)下,显著提高种子发芽率(P<0.05);中性至强碱胁迫(pH为7～11)下,显著提高种子的胚芽长及胚根长(P<0.05);酸性至中性条件(pH为4～7)下,显著提高幼苗干重;强酸(pH=4)及强碱(pH=11)胁迫下,E+异状发芽率显著低于E-(P<0.05)。弱酸至碱胁迫(pH为6～10)下,内生真菌显著提高中华羊茅种子发芽势(P<0.05);强酸(pH=4)及碱胁迫(pH为8～11)下,显著提高种子发芽率(P<0.05);pH为4～11,显著促进中华羊茅胚芽生长(P<0.05);pH=10时对胚根的增益作用显著(P<0.05);酸胁迫(pH为4～6)下,显著提高幼苗干重;强碱胁迫(pH=11)下,异状发芽率显著增加(P<0.05)。pH为4～11,内生真菌显著提高野大麦种子发芽势(P<0.05);碱胁迫(pH为9～11)下,显著促进种子胚芽生长(P<0.05);碱胁迫(pH为8～11)下,显著提高胚根长(P<0.05);pH为4～11,显著提高野大麦幼苗干重(P<0.05);强酸胁迫(pH=4)下,E+异状发芽率显著低于E-(P<0.05)。相对于胚芽,胚根对酸碱条件变化更敏感。综合考虑,最适萌发pH条件分别为:醉马草pH为6～9;中华羊茅pH为6～7;野大麦pH为7～9。Neotyphodium endophytes may improve host grass competitive abilities by increasing seed germination success and enhancing host plant growth under water stress,salt and other environmental stress conditions.To find if there were differences in germination between Neotyphodium endophyte infected（E＋） and uninfected（E-） plants of three grass species（Achnatherum inebrians,Festuca sinensis and Hordeum brevisubulatum）,eight pH levels（pH 4-11） were used.The results indicated that the germination energy of E＋ A.inebrians seed were much higher than those of E-seed at pH 6-11（P0.05）;the germination rate was significantly higher at pH 4-5;the shoot and radical growth of E＋ were higher than those of E-,especially at pH 7-11（P0.05）;and there was much higher dry weight at pH 4-7.The percentage of abnormal germination of E＋ seed at pH 4 and at pH 11 was significantly（P0.05） lower than that of E-seed.Similarly,E＋ F.sinensis seed performed much better than E-seed in germination rate,germination energy,radical growth,shoot growth and dry weight.There were significant differences in germination energy at pH 6-10（P0.05）,germination rate at pH 4 and pH 8-11（P0.05）,shoot growth at pH 4-11（P0.05）,radical growth at pH 10（P0.05）,and the dry weight of E＋ seedlings was significantly greater at pH 4-6（P0.05）.The percentage of abnormal germination was highest at pH 11（P0.05）.Compared with E-H.brevisubulatum,E＋ seed had greater germination energy at pH 4-11（P0.05）;the shoot and radical growth were significantly greater than those of E-seedlings at pH 9-11 and pH 8-11（P0.05） as was the dry weight at pH 4-11（P0.05）.The percentage of abnormal germination of E＋ seed was significantly less than that of E-seed at pH 4.Overall,the optimal pH value for A.inebrians was 6-9;for F.sinensis was 6-7,and for H.brevisubulatum was 7-9.

关 键 词：内生真菌 酸碱度 醉马草 中华羊茅 野大麦 萌发 

分 类 号：S543.9[农业科学—作物学]