盐碱胁迫下不同木霉菌肥对大豆幼苗氮代谢的影响

Effects of Different Trichoderma Fertilizers on Nitrogen Metabolism of Soybean Seedlings under Saline-alkali Stress

盐碱胁迫对大豆植株生长发育以及氮素吸收等造成不利影响,进而严重影响大豆的产量,而外源施用木霉菌肥是缓解盐碱对大豆胁迫效应的一种有效途径。因此为明确木霉菌对盐碱胁迫下大豆幼苗氮代谢影响机制,本研究选用耐盐碱品种合丰50(HF50),盐碱敏感品种垦丰16(KF16)为试材,采用苏打盐碱土进行盆栽培养,按照每升土1×10^(9)孢子·L^(-1)浇入200 mL哈茨木霉、棘孢木霉及木霉菌混合菌液,测定大豆幼苗叶绿体ATP合成及氮代谢等生理生化指标。结果显示:盐碱胁迫显著增加大豆幼苗体内NH+4含量,导致氨毒害,而施用不同木霉菌肥后显著降低了KF16和HF50大豆叶片NH4+含量,降幅分别为38.31%、41.56%、63.62%(KF16)和20.55%、25.58%、55.62%(HF50)。施用木霉菌剂后大豆叶片Ca^(2+)-ATP和Mg^(2+)-ATP酶活性较对照处理显著提高36.15%~65.22%(KF16)、28.51%~62.47%(HF50)和23.09%~62.58%(KF16)、14.37%~44.10%(HF50),进而促进叶片光合速率,为大豆幼苗氮代谢提供了更多原料和能量,从而提高了大豆氮代谢活性。结果说明不同木霉菌处理能够有效缓解盐碱胁迫对大豆造成的损害,从而促进大豆生长。

Salt and alkali stress has adverse effects on soybean plant growth and nitrogen absorption,which seriously affects soybean yield.Exogenous application of Trichoderma fertilizer is an effective way to alleviate the effect of salt and alkali stress on soybean.Therefore,in order to clarify the effect mechanism of Trichoderma on nitrogen metabolism of soybean seedlings under saline-alkali stress.In this experiment,the saline-tolerant cultivar Hefeng 50(HF50)and saline-alkali sensitive cultivar Kenfeng 16(KF16)were selected as test materials.Pot culture was carried out in saline-alkali soil,and 200 mL of spores of Trichoderma harzianum,Trichoderma asperellum and the Trichoderma mixture,1×10^(9) spores·L^(-1) per liter of soil were poured into the soil.Chloroplast ATP ase synthesis,nitrogen metabolism and other physiological and biochemical indexes of soybean seedlings were determined.The results showed that,salt and alkali stress significantly increased NH_(4)^(+) content in soybean seedlings,resulting in ammonia toxicity,while application of different trichoderma fertilizers significantly decreased NH_(4)^(+) content in KF16 and HF50 soybean leaves.The decreases were 38.31%,41.56%,63.62%(KF16)and 20.55%,25.58%,55.62%(HF50),respectively.Compared with the control treatment,the activities of Ca^(2+)-ATPase and Mg^(2+)-ATPase in soybean leaves were significantly increased by 36.15%-5.22%(KF16),28.51%-62.47%(HF50),23.09%-62.58%(KF16),and 14.37%-44.10%(HF50),and then promoted the photosynthetic rate of leaves to provide more raw materials and energy for the nitrogen metabolism of soybean seedlings,and then improved the nitrogen metabolic activity of soybean.In conclusion,the different Trichoderma treatments could effectively alleviate the damage caused by saline-alkali stress on soybean and promote its growth.