Analysis Of Genetic Variation Of SP₂ Biennial Population From Astragalus Membranaceus Seeds Carried In Space

Astragalus membranaceus is a perennial herb belonging to Astragalus Leguminosae.It is mainly produced in Gansu,Hebei,Shanxi,Heilongjiang,Jilin,Inner Mongolia and other places.Its root is used as medicine.It tastes sweet and warm.It has the effects of Tonifying Qi and Yang,promoting body fluid and nourishing blood.There are many kinds of Astragalus membranaceus,and there are some problems in cultivation,such as hybrid varieties,germplasm degradation and so on;Breeding new varieties of Astragalus membranaceus has become the key to improve the quality and yield of Astragalus membranaceus.In order to speed up the breeding of new varieties of perennial Astragalus membranaceus,the seeds were carried on"Shenzhou 11"and"Changzheng 7"in space for 33 days and 22 hours respectively.Under the condition of organic cultivation,the variability of SP₂ biennial population of Astragalus membranaceus established by seeds of different space flight modes was analyzed from the perspective of morphology and molecular biology,so as to reveal the effect of space flight modes on genetic diversity induction of Astragalus membranaceus,provide scientific basis for space breeding of Chinese medicinal materials,and improve the breeding efficiency of new varieties.The results are summarized as follows:1.Compared with"Shenzhou 11",the SP₂ population of Astragalus membranaceus seeds carrying"Changzheng 7"mutagenesis for 22 hours was more likely to cause variation in phenotypic morphological indexes of Astragalus membranaceus,and more variation was obtained.However,the two kinds of mutagenesis methods were more likely to cause variation in the plant shape,leaf and branch of Astragalus membranaceus patent medicine strains.2.The direction of variation and the degree of diversity of the plants were not consistent with the different spacefaring methods.The genetic diversity index of secondary branch number in the aboveground part was the highest,and the genetic diversity index of other morphological indexes in the aboveground part of the 33 days population was lower than that of the 22 hours population except plant height and stem diameter.The genetic diversity index of root length and root width was the highest,while the fresh root weight was the lowest.The mean coefficient of variation and the mean genetic diversity index of 33 days population were lower than those of 22 hours population.Astragalus membranaceus carried the 22 hours population of"Changzheng 7",and the plant shape and root shape were more diverse.3.Compared with other types of plants,type a plants with 33 days and 22 hours population and type B plants with 33 days population had higher photosynthetic efficiency,and type a plants with 33 days population had the highest net photosynthetic rate,The chlorophyll content in leaves of type a plants in 22 hours population was the highest,which indicated that the photosynthetic pathway was optimized and the photosynthetic efficiency was improved by increasing the photosynthetic pigment content.The mean value of antioxidant enzyme activity in leaves of 22 hours population was the highest,and the antioxidant enzyme activity was strong.4.The genetic diversity of SSR loci was high in both populations.The genetic distances of 33 days and 22 hours populations were 0-0.8959 and 0.0270-0.9435,respectively,and the genetic similarity coefficients were 0.4000-1.000 and 0.3846-0.9730,respectively.The lowest genetic similarity coefficient of 33 days population was between No.2 and No.25,No.2 and No.32,and the similarity coefficient of each group was 0.4000.The highest genetic similarity coefficient was between No.23 and No.24,and the similarity coefficient between materials was 1.000.The genetic similarity coefficient of 22 hours population was 0.3846 for plants 6and 44,and 0.9730 for plants 11 and 14.5.Based on the analysis of phenotypic traits and SSR molecular markers,it was revealed that the SP₂ population of Astragalus membranaceus carried in space had rich genetic diversity,33 days and 22 hours.The average coefficient of variation of H population was29.37%and 26.17%,the average genetic diversity index was 1.27 and 1.22,and the average polymorphism information value of each pair of primers was 0.320 and 0.427,respectively.The clustering results could clearly distinguish different types of plants,and the genetic diversity of 22 hours population was higher than that of 33 days population There were significant differences in phenotypic traits between the two groups.Space flight created a relatively rich population of genetic diversity.