盐胁迫下内生真菌对国槐幼苗生长及生理的影响

Effect of endophytic fungi on growth and physiology of saline stressed Sophora japonica seedlings

以盆栽国槐Sophora japonica幼苗为试材,进行200 mmol·L-1氯化钠(NaCl)胁迫处理,采用菌液定量灌根法,通过测定国槐苗高增长量、根冠比、干质量,丙二醛(MDA)质量摩尔浓度,叶绿素、脯氨酸(Pro)质量分数,超氧化物歧化酶(SOD)和过氧化物酶(POD)活性等生理指标,探讨8株优势内生真菌分别灌根对国槐幼苗生长及生理的影响。结果表明:200 mmol·L-1氯化钠胁迫下,每种菌株处理下的国槐幼苗生物量与生理变化趋势基本一致。菌株H-1,H-3,H-4和H-6灌根处理的国槐幼苗抗盐能力提高,其中,菌株H-3的促进作用最明显,幼苗高增长量、干质量、根冠比和鲜质量含水量显著高于对照(ck),分别为对照的148%,117%,121%和104%,生理指标丙二醛质量摩尔浓度和脯氨酸质量分数为对照的88%和151%,差异分别达到显著水平(P<0.05);H-5处理的国槐幼苗抗盐能力降低,幼苗高增长量、干质量和根冠比显著低于对照,分别为对照的69%,83%和78%,生理指标脯氨酸质量分数和过氧化物酶活性为对照的81%和72%,差异分别达到显著水平(P<0.05);其他菌株处理的国槐幼苗抗盐能力不明显。综合各项指标得出,H-1,H-3,H-4和H-6为促生能力优势菌,具有应用潜力。

To explore salt tolerance of Sophora japonica with functional endophytic fungi, eight strains of fungi（H-1 through H-8） were used to inoculate S. japonica seedlings along with 200 mmol·L^-1Na Cl stress added by root-irrigation. Seedling height, root/shoot ratio, dry weight, water content, chlorophyll content, proline content,malondialdehyde（MDA） content, superoxide dismutase（SOD） and peroxidase（POD） activities were detected.Results showed that with 200 mmol·L^-1NaCl stress, the changes of seedling biomass were basically the same as the tendency of physiological index varied. The H-1, H-3, H-4, and H-6 strains improved salt resistance of S.japonica seedlings. Strain H-3 was significantly higher than the control（P〈0.05） for seedling height（148%）,dry weight（117%）, root/shoot ratio（121%）, and water content（104%）. Compared to the control, MDA was88% and Pro was 151%, the difference reached significant level（P〈0.05）. Strain H-5 had the opposite affect with seedling height（69%）, dry weight（83%）, and root/shoot ratio（78%）, which were all significantly lower than the control（P〈0.05）; also proline was 81% and POD activity was 72% of the control, and the difference reached significant level（P〈0.05）. Over all, H-1, H-3, H-4, and H-6, the dominant strains among the tested endophytes, would have great potential for application.