| Salvia miltiorrhiza Bge.is one of the genuine medicinal materials in Henan Province,and Western Henan is the main producing area of S.miltiorrhiza.In view of the weakness of drought resistance research and the lack of drought resistance evaluation index of S.miltiorrhiza,four cultivation types(SA,SB,SC,SD)with different drought resistance selected by the research group in the early stage were used as experimental materials,and the drought resistance index screening and comprehensive evaluation of S.miltiorrhiza were carried out by using morphological observation,physiological index,chemical component content determination and other research methods,In order to provide reference for drought resistant breeding and identification of S.miltiorrhiza,and lay a foundation for improving the yield and quality of S.miltiorrhiza in dry farming area.The main results are as follows:1.Through the determination of growth indexes in germination period,it was found that the growth of radicle and germ of various cultivation types of S.miltiorrhiza was significantly inhibited under drought stress.The cultivation types with stronger drought resistance in germination period showed larger values of radicle length,cotyledon length and width,germination index,vigor index and other indexes with smaller variation.The relative leaf width,relative vigor index,relative germ length,relative radicle length,relative leaf length,relative ten bud weight and relative germination index can be used as drought resistance identification indexes of S.miltiorrhiza during germination.The drought resistance of four cultivation types of S.miltiorrhiza was analyzed by membership function method.The order of drought resistance was SA,SD,SB and SC.2.Through the determination of morphological characteristics and physiological indexes at seedling stage,it was found that the plant height,leaf length,leaf width,petiole length,leaf number and root length of S.miltiorrhiza were significantly inhibited under drought stress.With the increase of drought degree,the activities of SOD,POD and CAT and the content of malondialdehyde first increased and then decreased,while the content of soluble protein,soluble sugar and proline still accumulated.The results showed that the drought resistance of S.miltiorrhiza seedlings was strong,the activities of SOD and CAT were higher,and the proline accumulation was less.With the strengthening of drought stress,plant height,stem diameter,leaf length,leaf width,root length,anthocyanin index,soluble sugar and other indicators decreased less.Based on the analysis of principal component and membership function,it was found that root length,total root projection area,total root volume and chlorophyll index could be used as drought resistance indexes in seedling stage.According to D value(comprehensive evaluation value of drought resistance),the drought resistance of four cultivation types of S.miltiorrhiza at seedling stage were SD,SA,SC and SB.3.Through the determination of Agronomic Traits in flowering and fruiting stage,it was found that the differences of inflorescence length,leaf width,petiole length,lateral root length,number of primary lateral roots,dry and fresh weight of underground part,dry weight of aboveground part and root shoot ratio of S.miltiorrhiza cultivation type with strong drought resistance in flowering and fruiting stage were small compared with the control.Based on the analysis of principal component and membership function,it was found that the number of branches,the number of branches and the fresh weight of underground part could be used as the identification index.According to the D value,the drought resistance of four cultivation types of S.miltiorrhiza at flowering and fruiting stage were SD,SC,SB and SA.4.Through the determination of agronomic traits and index components of S.miltiorrhiza in harvest period,it was found that compared with the control,root length of different cultivation types of S.miltiorrhiza under drought treatment was inhibited except SD type,stem diameter was increased except SC type,and the content of chemical components of different types was different.It was found that the contents of rosmarinic acid and salvianolic acid B in S.miltiorrhiza with strong drought resistance during harvest period were higher than those in control group,and the changes of main root length,lateral root length,main root diameter and salvianolic acid B were smaller.Principal component analysis combined with subordinate function analysis showed that fresh weight of underground,tanshinone ⅡA and salvianolic acid B were used as drought resistance identification indexes of S.miltiorrhiza.According to the D value,the drought resistance of four cultivation types of S.miltiorrhiza at harvest was SA,SD,SB and SC. |
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