广藿香^(60)Co-γ射线辐射诱变植株的筛选及评价

Screening and Evaluation of Induced Mutation by ^(60)Co-γRadiation of Pogostemon cablin(Blanco)Benth.

为应对广藿香药材需求量急速增加、无突出优点的品种且品种单一的情况,解决广藿香道地药材缺失及种质退化、种质来源混乱、易遭受病害虫害等问题,本研究通过辐照诱变育种,设置梯度剂量的^(60)Co-γ射线,对愈伤组织、丛生芽、生根苗3种不同生长阶段的广藿香进行辐照处理,观测再生植株外观形态,筛选出变异植株,测量其农艺性状和生理生化指标,采用气相色谱-质谱联用技术(GC-MS)测定其主要挥发性成分广藿香酮及百秋李醇含量。结果表明:愈伤组织和丛生芽对^(60)Co-γ射线较为敏感,死亡率较高,生根苗对^(60)Co-γ射线较为耐受,死亡率较低,最佳诱变育种的方式是采用100Gy^(60)Co-γ射线辐照处理生根苗,其诱变率高达10%。本研究最终获得29株广藿香变异植株,分别为三叶轮生、异型叶、深裂叶、狭叶、卷叶、下卷叶和紫色叶7种形态类型植株,通过比较分析渗透调节物质(可溶性糖、可溶性蛋白和游离脯氨酸)、抗氧化物质(丙二醛、过氧化物酶、过氧化氢酶)、广藿香酮和百秋李醇含量,最终筛选得到15株具有潜力植株,分别为:抗逆且高有效成分植株SY7和ZY1;对环境敏感且高有效成分植株SY15、SY18和XY1;抗逆植株SY2、SY6、SY19、YY2、YY9和XJY1;高有效成分植株SY10和SY17;“酮型”广藿香植株SY3和JY1。其中SY7和ZY1为双重优良特性新种质,2株“酮型”广藿香植株对于解决道地药材缺失及其种质退化等问题具有应用价值。本研究采用^(60)Co-γ射线辐照诱变方法选育的广藿香变异植株,具有较强抗逆性、高有效成分等优点,为广藿香诱变育种以及新品种选育提供成熟方法和潜在种质。

The study was aimed to cope with the rapid increase in demand for patchouli[Pogostemon cablin(Blanco)Benth.]and to solve the problems of lack of patchouli medicinal materials,germplasm degradation,confusion of germ-plasm sources,and vulnerability to diseases and pests.Callus,cluster buds and rooting seedling of patchouli were irra-diated with a gradient dose of ^(60)Co-γrays.The appearance and morphology of regenerated plants were observed,the mutated plants were screened,the agronomic traits and physiological and biochemical indicators were measured,and the content of pogostone and patchouli alcohol,the main volatile components,were determined by gas chromatogra-phy-mass spectrometry(GC-MS).The results showed that calluses and cluster buds were more sensitive to ^(60)Co-γrays and had higher mortality rate,while rooting seedlings were more tolerant to ^(60)Co-γrays and had lower mortality.The best way to breed mutagenesis is ^(60)Co-γtreated rooting seedlings with irradiation doses of 100 Gy with a mutagenesis rate of up to 10%.In this experiment,29 patchouli variant plants were obtained,which were divided into seven mor-phological types,namely three-leaf whorls,heteromorphic leaves,deep-split leaves,narrow leaves,coiled leaves,un-dercoiled leaves and purple leaves.The contents of osmotic conditioning substances[soluble sugar,soluble protein and free proline(Pro)],antioxidant substances[malondialdehyde(MDA),peroxidase(POD),catalase(CAT)],pogostone and patchouli alcohol were compared and analyzed.According to the analysis results of the above determination indicators,15 potential plants were finally screened,namely:stress-resistant plants with high effective components SY7 and ZY1;environmentally sensitive plants with high effective components SY15,SY18 and XY1;stress-resistant plants SY2,SY6,SY19,YY2,YY9 and XJY1;high active ingredient plants SY10 and SY17;“pogostone-type”patchouli plants SY3 and JY1.Among them,SY7 and ZY1 are new germplasms with double excellent characteristics,and the two“pogos-tone-type”patchouli plants have application value for solving the problems of the lack of authentic medicinal materials and the degradation of germplasm.In this study,patchouli variant plants bred by the ^(60)Co-γray irradiation mutagenesis method have the advantages of strong stress resistance and high active ingredients,which would provide mature meth-ods and potential germplasm for patchouli mutagenesis breeding and new variety breeding.