Studies On The Effects Of Drought Stress On The Growth And Physiological And Biochemical Characters Of Pinellia Ternata Germplasm

In order to study the impact of drought stress on different germplasms of Pinellia(Pinellia ternata),and provide scientific basis for breeding and efficient cultivation techniques of Pinellia ternata,the five Pinellia germplasms in Changde,Yuanling,Ziyang,Bijie,and Jingshan in Hunan Province and surrounding areas(cities &districts)were used as research materials.Under the three cultivation environment conditions including forest drought stress control treatment(soil moisture content is70% to 75% of field water capacity,CK),mild drought stress(60% to 65%,T1)and severe drought stress(50% to 55%,T2),comparative analysis was conducted on the agronomic traits such as leaf length,leaf width,leaf thickness,leaf number,leaf area,plant height,stem thickness,tuber fresh weight and dry weight,leaf fresh weight and dry weight;chlorophyll content and CAT,POD,SOD enzyme activity as well as pinellia tuber alkaloids,succinic acid and guanosine content to obtain the following main research results.1.Agronomic traits such as leaf length,leaf width,leaf thickness,leaf number,leaf area,plant height,stem thickness,tuber fresh weight and dry weight,leaf fresh weight and dry weight of Pinellia ternata under different drought stress vary significantly in 5 germplasms.To be more specific,significant level difference(P<0.01)exists between the agronomic traits of Pinellia germplasm in Ziyang and Jingshan.Furthermore,the agronomic traits of Pinellia germplasm in Ziyang represented the highest value among the five germplasms tested,while the agronomic traits of the Pinellia germplasm in Jingshan represented the lowest values under different drought stress conditions.2.The chlorophyll content and the activity of the three antioxidant enzymes including CAT,POD and SOD of the five Pinellia ternata germplasms vary significantly under different drought stress conditions.To be more specific,the aforesaid variation of the Ziyang germplasm represented a stable and relatively high level under the three draught stress conditions,indicating that the three antioxidant enzyme systems,ie,SOD,CAT and POD of the Ziyang germplasm could regulate stably in response to different drought stress conditions and maintain normal metabolism of plant somatic cell function;The variation in the activity of the three antioxidant enzymes including CAT,POD and SOD of the Jingshan germplasm was significant and maintained high level under different drought stress conditions,and the variation level was obviously or significantly different from that of the other 4germplasm,indicating that the aforesaid three antioxidant enzymes of the Jingshan germplasm could not maintain stable regulation in response to different draught stress conditions,and the maintenance of normal metabolic function of its plant somatic cells would be affected..3.The content of the 3 medicinal ingredients including alkaloid,succinic acid and guanosine of the five Pinellia ternata germplasms vary significantly under different drought stress conditions.To be more specific,although the aforesaid content of the Ziyang germplasm also showed a change that first decreased and then increased as the degree of drought stress increased from CK to T1 to T2 treatment,the content of the three medicinal active ingredients all maintained a high level and were higher than those of the other four germplasms,indicating that the Ziyang germplasm not only had strong resistance to drought stress with robust growth and development characteristics,but also contained excellent medicinal functional ingredients with high quality.In addition,the Jingshan germplasm not only had weak resistance to drought stress with poor growth and development characteristics,but also contained low-quality medicinal functional ingredients.The quality of the medicinal functional ingredients of the Changde,Yuanling and Bijie germplasms was medium.