复盐胁迫对2种虉草苗期生长的影响

用不同浓度的中性盐和碱性盐对虉草新品系（Phalaris arundinacea L.New strain）和川草3号虉草（Phalaris arundinacea L.Chuan cao No.3）幼苗进行21 d的处理,测定株高、地上生物量、地下生物量、枯叶率和分蘖率,探讨复盐胁迫对2种虉草苗期生长的影响.结果表明,在盐浓度50 mmol/L时,虉草地上生物量、地下生物量和分蘖率最大;当盐浓度超过50 mmol/L时,随着盐浓度增加,生物量和分蘖率均呈现递降的趋势,而枯叶率递增;盐浓度与株高生长速度呈明显的负效应;在等盐浓度的中性盐胁迫下,新品系地下生物量大于地上生物量,而在碱性盐胁迫下,前者小于后者.表明低浓度的盐胁迫对虉草生物量积累和分蘖具有一定的促进作用;虉草对碱性盐胁迫更敏感.

Effects of Complex Salt Stress on the Seedling Growth of Two Reed Canarygrass

The seedlings of new strain of reed canarygrass and Chuancao No.3 reed canarygrass were grown under stress of salt-alkalinizcal soil simulated with mixing two neutral salts and two alkalie salts in various proportions,for 21 days.The plant height,aboveground biomass,underground biomass,rate of withered leaves and tiller rate of two reed canarygrass under the stresses was determined,in order to study the effects of mixing saline stress on the seedlings growth.The results showed that the aboveground biomass,underground biomass and tiller rate for two reed canarygrass all were highest under 50 mmol/ L saline stresses,When salt concentration was higher than 50 mmol/L,the biomass and tiller rate was differently decreased and rate of withered leaves increased gradually with the increased of salt concentration.The growing rate of the reed canarygrass seedling was obviously negative effects with salt concentration.At same salt concentration,underground biomass of new strain was higher than aboveground biomass under neutral salt stress,while the former was lower than the latter under alkaline salt stress.This showed that low salt stress had some promotion effect on the increase of biomass and tiller of the reed canarygrass seedling.