标题:
天然禾草中三种内生真菌对非生物胁迫耐性的比较研究Responses of Three Endophyte Fungi Species Isolated from Natural Grass to Abiotic Stresses
作者:
魏茂英, 尹立佳, 贾彤, 朱敏杰, 高玉葆
关键字:
Neotyphodium, 内生真菌, 生理, 天然禾草, 抗逆性Neotyphodium; Endophyte; Physiology; Natural Grass; Resistance
期刊名称:
《Botanical Research》, Vol.1 No.1, 2012-04-06
摘要:
从天然禾草羽茅和羊草中分离获得3种不同的内生真菌，即Neotyphodium gansuense、 Neotyphodium sibiricum和Neotyphodium sp.。在不同的温度、盐分和渗透胁迫条件下比较3种内生真菌的生长状况，并以分离自高羊茅中的模式菌株Neotyphodium coenophialum为对照。结果表明，3种内生真菌与模式菌株的最适生长温度均为25℃，但模式菌株N. coenophialum在32℃时没有生长，而从天然禾草中分离获得的内生真菌在10℃-32℃温度范围内均可生长。当PEG浓度超过15%时，3种内生真菌与模式菌株均不能生长，N. sp.在10%时仍长势良好，与N. coenophialum相似，而N. sibiricum和N. gansuense在10%PEG浓度时，生长受到显著抑制。在盐分处理时，N. sp.和N. gansuense在0.3 mol/L的NaCl浓度下，生长受到显著抑制；而N. sibiricum在1.5 mol/L的NaCl浓度时生长才受到显著抑制，但耐盐性均不及N. coenophialum，后者在3.0 mol/L的NaCl浓度下还可以生长。总体看来，从天然禾草中获得的3种内生真菌与模式菌株相比较，耐高温的能力更强；耐渗透胁迫的能力只有羊草中的N. sp.与模式菌株接近，而羽茅中的两种菌株的耐渗透胁迫能力却显著低于模式菌株；对于不同的盐浓度胁迫，3种菌株的耐盐性都显著低于模式菌株。不同种类内生真菌在渗透胁迫方面的耐性与其宿主植物表现相一致。
Biological and physiological characteristics of three Neotyphodium species, isolated from native grasses, were compared with the model endophyte Neotyphodium coenophialum, isolated from tall fescues, under different temperature, water and salt conditions. Three Neotyphodium species included Neotyphodium gansuense, Neotyphodium sibiricum and Neotyphodium sp, among which N. sp was isolated from Leymus chinensis while the other two species were isolated from Achanatherum sibiricum. The results showed that the optimal temperature for the four endophytes was 25˚C. The model endophyte N. coenophialum was un-able to grow at 32˚C, but the other endophytes were able to grow at 10˚C - 32˚C. Four fungi could not grow when the PEG concentration was 15%. For N. sp., it tended to increase when PEG concentration was 10%, and this situation is similar to N. coenophialum. For N. gansuense and N. sibiricum, the growth was not in-fluenced till the PEG concentration was up to 10%. Under the treatment of NaCl, the biomass of N. sibiricum and N. coenophialum significantly increased, but the growth of N. gansuense and N. sp. were significantly re-strained at 0.3mol/L NaCl. N. sibiricum was unable to grow at 1.5mol/L NaCl, but N. coenophialum can still grow under 3 mol/L NaCl. As a result, three species of endophytes which were isolated from native grasses can tolerate high temperature than the model endophyte. For the ability of resistance to osmotic stress, only N. sp. is similar to the model endophyte and two endophytes from A. sibiricum was significantly lower than model endophyte. For different salt stress, the tolerance of three native species was significantly lower than the model species.