冀东野生大豆(Glycine soja)耐盐碱性鉴定及耐性生理指标测定

为充分利用盐碱地资源,明确野生大豆耐盐碱生理机制,本研究对采集于冀东地区的349份野生大豆种质资源进行耐盐碱性鉴定,测定了高耐材料2010-12和敏感材料2012-34、2012-49在0、100和200 mmol·L^-1盐碱胁迫下的丙二醛、脯氨酸和可溶性糖含量、电解质外渗率以及脯氨酸代谢关键酶吡咯琳-5-羧酸合成酶(GmP5CS)、吡咯琳-5-羧酸还原酶(GmP5CR)、脯氨酸脱氢酶(GmPDH)及谷胱甘肽S-转移酶19(GsGST19)相关基因的表达量。结果表明,表现耐性等级1级的高耐材料有2份(Yong 2和2010-12),表现耐性等级2级的耐性材料有22份,表现耐性等级3、4、5级的材料各有80、77和161份。与CK相比,高耐野生大豆材料2010-12在盐碱胁迫下脯氨酸及可溶性糖含量显著升高,丙二醛含量及电解质外渗率无显著差异。在高耐盐碱野生大豆材料中,GmP5CS、GmP5CR和GsGST19基因表达量上调,GmPDH基因表达量下调。以上结果表明高耐野生大豆材料在盐碱胁迫下脯氨酸合成通路激活,脯氨酸含量升高,说明脯氨酸在野生大豆对抗盐碱胁迫中发挥重要作用。本研究筛选的高耐盐碱野生大豆材料可为培育耐盐碱栽培大豆提供优异种质。

Identification of Saline-Alkali Stress and Determination of Physiological Index of Wild Soybean (Glycine soja) in Eastern Hebei Province

To fully utilize the saline-alkali land resources and clarify the saline-alkali tolerance mechanism of wild soybeans, the tolerance of saline-alkali stress of 349 wild soybean germplasm resources collected in the east of Hebei Province were identified. In the present study, we estimated the malondialdehyde and proline, soluble sugar contents and electrolyte leakage rate of wild soybean materials 2010-12, 2012-34 and 2012-49 under 0, 100 mmol·L^-1and 200 mmol·L^-1saline-alkali stress. We also detected the expression levels of pyrroline-5-carboxylate synthetase (GmP5CS), Pyrroline-5-carboxylate reductase (GmP5CR), proline dehydrogenase (GmPDH) and glutathione S-transferases (GsGST19) genes. The results showed that two wild soybean germplasms were tolerance grade 1 (Yong 2 and 2010-12); 22 wild soybean germplasms were tolerance grade 2; 80 wild soybean germplasms were tolerance grade 3; 77 wild soybean germplasms were tolerance grade 4 and 161 wild soybean germplasms were tolerance grade 5. Under saline-alkali stress, compared with the control, the contents of proline and soluble sugar in high-saline-alkali tolerant wild soybean materials increased significantly, while the contents of malondialdehyde and electrolyte leakage rate decreased significantly. The expression levels of GmP5CS, GmP5CR and GsGST19 were up-regulated in high-saline-alkali tolerant materials, and the expression levels of GmPDH were down-regulated in high-saline-alkali tolerant materials. These findings showed that proline synthesis pathway was activated and proline content was increased in high-saline-alkali tolerant wild soybean materials with salt alkali stress, indicating that proline played an important role in the resistance of wild soybean to saline-alkali stress. In conclusion, the wild soybean germplasms with high tolerance to saline-alkali stress can be used as the tolerant source for soybean breeding programs.