【作者】 程玉娥；

【导师】 唐明；

【作者基本信息】 西北农林科技大学 ， 森林保护学， 2010， 硕士

【摘要】 本文研究了PEG模拟干旱胁迫条件下,3种外生菌根真菌(Ectomycorrhizal fungi, ECMF)—褐黄牛肝菌(Boletus luridus,简称B.l)、粘盖牛肝菌(Suillus bovinus,简称S.b)和褐环粘盖牛肝菌(Suillus luteus,简称S.l)的菌丝生长及其营养代谢情况,并用抗旱性较强的褐黄牛肝菌(B.l)和粘盖牛肝菌(S.b)接种大青杨(Populus ussuriensis)幼苗,研究干旱胁迫下杨树菌根化苗的生理指标变化,以及叶绿素荧光特性的响应,探讨ECMF促进杨树抗旱的机制。得出以下主要结论：1.干旱胁迫对外生菌根真菌生长及其营养代谢的影响①PEG模拟干旱胁迫下,3种ECMF菌落直径增长保持S生长模式,且较强干旱胁迫下(水势≤-0.49 MPa),各ECMF的指数期相对于对照(水势0 MPa)都滞后1-2 d。较弱干旱胁迫(水势≥-0.15 MPa)对3种ECMF生长没有影响,有的甚至有所促进,但与对照相比没有显著差异(P>0.05)；较强干旱胁迫(水势≤-0.49 MPa)对3种ECMF菌丝生长及生物量积累产生抑制,且差异显著(P<0.05)。方差分析表明,各干旱胁迫条件下,B.l和S.b的菌落生长趋势大致相同,没有显著菌间差异(P>0.05),较弱干旱胁迫下(水势≥-0.15 MPa),S.l菌落生长与B.l和S.b间没有显著菌间差异(P>0.05),较强干旱胁迫下(水势≤-0.49 MPa),S.l与B.l和S.b相比菌丝生长明显受到抑制,存在显著菌间差异(P<0.05)。②干旱胁迫下,3种ECMF对营养元素的消耗趋势基本相同,较弱干旱胁迫(水势≥-0.15 MPa)对3种ECMF碳、氮、磷的消耗利用情况均无显著影响,较强干旱胁迫均显著降低了菌丝生长所需的碳、氮、磷的消耗速度；营养液中微量营养元素钾相对消耗量的变化与碳、氮、磷的变化规律相反,3种ECMF消耗速度均随干旱胁迫的增强而显著升高。3种ECMF各营养元素的相对消耗量菌间差异显著(P<0.05),各个菌种间碳的消耗速度排序为：S.b>B.l>S.l,氮、磷、钾的消耗速度排序为：B.l>S.b>S.l③干旱胁迫对3种ECMF的作用存在菌间差异,B.l和S.b对干旱胁迫的耐受性在生长和营养代谢方面都显著高于S.l菌,表现出较强的抗旱性。在选育抗旱菌种上B.l和S.b可作为优势菌种。2.干旱胁迫下外生菌根真菌对杨树生理指标的影响①外生菌根真菌B.l和S.b接种杨树后显著促进了杨树株高和地径的生长,其中S.b对杨树的促生长作用大于B.l,比较两种ECMF对杨树的侵染率得出：侵染率的高低与促生长作用成正相关。②干旱胁迫使杨树叶片的含水量下降,SOD活性、CAT活性、游离脯氨酸含量、MDA含量升高。但相同时间、相同胁迫水势下,接种B.l和S.b的杨树叶片含水量、SOD活性、CAT活性、游离脯氨酸含量均显著高于CK(未接种)(P<0.05),细胞膜脂质过氧化的产物MDA的含量显著低于CK(P<0.05)。接种菌根真菌增强了杨树的生理抗旱性,其中S.b对杨树抗旱性的增强作用显著优于B.l(P<0.05)。3.干旱胁迫下外生菌根真菌对杨树光合作用的影响①干旱胁迫使杨树叶片的叶绿素含量下降,但相同时间、相同胁迫水势下,接种B.l和S.b的杨树叶片的叶绿素含量下降幅度要显著低于CK(P<0.05),从而保持了较高的吸光能力,进而提高了杨树抵抗干旱的能力。②干旱胁迫使杨树的叶片的叶绿素荧光参数——可变荧光(Fv)、PSⅡ原初光能转化效率(Fv/Fm)、PSⅡ的潜在活性(Fv/Fo)显著下降,说明水分胁迫使杨树幼苗叶片PSⅡ反应中心受到伤害,抑制了光合作用原初反应过程。但相同时间、相同胁迫水势下,接种B.l和S.b的杨树叶片Fv、Fv/Fm、Fv/Fo的降幅显著低于CK(P<0.05),从而降低了水分胁迫对杨树幼苗叶片PSⅡ反应中心的伤害,保持了较强的光合能力,提高了杨树的抗旱性,其中,S.b对杨树抗旱性的增强作用显著优于B.l(P<0.05)。4.综合本实验结果,3种外生菌根真菌中,粘盖牛肝菌(Suillus bovinus)对大青杨抗旱作用最强。更多还原

【Abstract】 In this paper, the growth and nutrition metabolism of three kinds of ECMF(Boletus luridus, Suillus bovinus, Suillus luteus) were studied under the drought stress which was formed by PEG. We inoculate B.l and S.b which were able to resistant drought esistance into Populus ussuriensis, then, the changing of physiological index and Chlorophyll fluorescence of the mycorhizal plants were studied under drought stress. Reveal the mechanism of ECMF promote drought resistance of their host. The major results were as follow:1. Effects of drought stress on the growth and nutrition metabolism of ECMFThe diameter growth of three ECMF remain keeping S-Tape under drought stress which was formed by PEG, and exponential phase of every mycelial was postponed 1-2 days under stronger drought stress (the water potential≤-0.49 MPa), and there was no significant different between three kinds of ECMF and CK with weak drought stress(.P>0.05); Under stronger drought stress (the water potential≤-0.49 MPa), the Mycelial growth and biomass accumulation of three ECMF was inhibited with significant differences(P<0.05). Variance analysis showed that B.l and S.b were similar in the colony growth trends under the drought stress, which has no significant difference between strains (P> 0.05). The colony growth of S.l has no significant difference with B.l and S.b (P<0.05), under the less drought stress (water potential≥-0.15 MPa). The mycelial growth of S.l was strongly inhibited compared to B.l and S.b, and there are significant differences between strains (P<0.05)The consumption trends of nutrient were more or less the same under drought stress. there was no significant effects on the consumption of C, N, P under weak drought stress (the water potential≥-0.15 MPa), but under stronger drought stress, the consumption of macroelement for mycelia growth was decreased, on the contrary, the consumption of microelement K was significantly promoted with the increase of drought stress. The relative consumption nutrient of 3 each ECMF differed significantly between strains (P<0.05). The consumption rate of each species odered as follow:S.b>B.l>S.l. The consumption rate of nitrogen, phosphorus and potassium odered as follow:B.l>S.b>S.l.The effects of drought stress on the three ECMF was different, the tolerance to drought stress of B.l and S.b was higher than S.l in aspects of mycelial growth and nutrition metabolism, therefore, B.l and S.b can be used as a dominant species. B.l and S.b can be used as dominant species in breeding species with drought resistant.2. Effects of ECMF on the physiological index of P. ussuriensis under drought stress.The stem length and diameter of P. sussuriensis was significantly promoted after B.l and S.b was inoculated, and the effect of S.l was stronger than B.l. The infection rate was positive correlated with growth-promoting.The Leaf Water Content decreased, SOD, CAT activity, free Pro and MDA contents increased under drought stress. But in P. ussuriensis inoculated with B.I and S.b, Leaf Water Content, SOD, CAT activity, free Pro was significantly higher than CK (P<0.05), MDA content was significantly lower than CK (P<0.05), therefore, the drought resistance of P. ussuriensis was promoted, and the effect of S.l was stronger than B.l (P<0.05).3 ECMF the relative consumption of each nutrient was significant difference between strains (P<0.05), various species of carbon consumption rate between the order of:Sb> Bl> Sl, nitrogen, phosphorus and potassium consumption rate of the order of:Bl> Sb> Sl.3. Effects of ECMF on the photosynthesis of P. ussuriensis under drought stressChlorophyll Content of P. ussuriensis decreased under drought stress, but in the same time and same water stress, the Decrease of Chlorophyll Content in P. ussuriensis inoculated ECMF was significantly lower than CK (P<0.05), thus a high absorption capacity was maintained and the drought resistance was promoted.Chlorophyll fluorescence parameters—Fv, Fv/Fm, Fv/Fo was significantly decreased under water stress, which showed that the PSⅡaction center in P. ussuriensis seedlings was taking damaged, thus the primary reaction of photosynthesis was inhibited, but in the same time and same water stress, the decrease of Fv, Fv/Fm, Fv/Fo in P. ussuriensis inoculated ECMF was significantly lower than CK (P<0.05), therefore the mischief of PSⅡwas decreased, the drought resistance was promoted, and the effect of S.l was stronger than B.l (P<0 .05).4. In a word, S.b was the most helpful fungi for P. ussuriensis to resistent drought stress in the 3 species of Ectomycorrhizal fungi.更多还原