干旱胁迫下EMS诱变大豆生理生化特性研究

Physiological and Biochemical Characteristics of EMS Mutagenic Soybean under Drought Stress

为了解析化学诱变剂—甲基磺酸乙酯(ethylmethane sulfonate,EMS)诱变后大豆耐旱性植株的生理生化特性变化,探讨EMS诱变选育抗旱大豆材料的可行性,本研究选取一级抗旱品种汾豆93为材料,对其进行EMS诱变处理,筛选长势较好的EMS诱变植株,进行干旱胁迫,调查植株生长状况,分析生理生化指标,并采用石蜡切片法观察组织解剖结构变化情况。结果显示:在正常处理下,对照植株和EMS植株的表型差异不明显;而在PEG干旱处理下,对照植株叶片显著萎蔫、枯黄,而EMS植株则长势良好,且其地上部和根部生物量均显著高于对照植株,其中EMS植株叶片中超氧化物歧化酶(SOD)和过氧化物酶(POD)活性分别为对照植株的1.30~1.41倍和1.23~1.38倍,而过氧化氢(H2O2)和丙二醛(MDA)含量则是对照植株的0.56~0.65倍和0.55~0.69倍。从植株组织石蜡切片中看出,EMS植株叶片和根部的组织结构较完整,且染色均匀,其中叶片上表皮、下表皮和栅栏组织厚度分别约是对照植株的1.71,1.81和1.65倍;海绵组织厚度则约是对照植株的0.32倍;根表皮和皮层厚度约为对照植株的0.33倍和0.36倍;木质部和韧皮部厚度分别是对照植株的1.25倍和1.65倍。EMS诱变可获得能够通过生理生化变化和组织结构变化抵御干旱胁迫的大豆植株,可用于抗旱大豆材料选育。

In order to analyze the physiological and biochemical characteristics of drought-tolerant soybean plants after the chemical mutagen agent ethylmethane sulfonate(EMS)mutagenesis,and to explore the feasibility of EMS mutagenesis to breed drought-resistant soybean materials,this study used the first-class drought-resistant variety Fendou 93 as the material,treated it with EMS mutagenesis,screened the better-growing EMS mutagenic plants and carried out drought stress.Then we investigated the growth status of plants,analyzed physiological and biochemical indicators,and observed the changes in tissue anatomy with paraffin sectioning.Under normal treatment,phenotypic differences between control and EMS plants were not significant.Under PEG drought treatment,the leaves of the control plants significantly wilted and withered,while the EMS plants grew well.The biomass of shoot and root was significantly higher than that of the control plant.The activities of superoxide dismutase(SOD)and peroxidase(POD)in the leaves were 1.30-1.41 times and 1.23-1.38 times of the control plant,respectively.The contents of hydrogen peroxide(H2O2)and malondialdehyde(MDA)were 0.56-0.65 times and 0.55-0.69 times of the control plant.From that anatomical structure of the plant tissue,the paraffin sections of the leave and roots of the EMS plant were complete in tissue structure and uniform in staining relatively.The thickness of that upper epidermis,the low epidermis and the palisade tissue of the leaves were about 1.71,1.81 and 1.65 times of the control plant,respectively.The thickness of spongy tissue was about 0.32 times of the control plant.The thickness of root epidermis and cortex was about 0.33 and 0.36 times of the control plant.The thickness of xylem and phloem was 1.25 and 1.65 times of control,respectively.EMS mutagenesis can obtain soybean plants that can respond to drought stress through physiological biochemical changes and tissue structure changes,which can be used for further selection and breeding of drought-resistant soybean materials.