Analysis Of Heterotic And Combining Ability About 14 Isatis Indigotica Fortune Inbred Lines

OBJECTIVE:The study used 14 inbred lines of Isatis indigotica to prepare 33 hybrid combinations,through the study of agronomic traits,photosynthetic traits and chemical quality of parents and F₁ plants,analysis their combining ability and genetic related characteristics,The purpose is to explore the Heterosis of Isatis indigotica,to provide the reference for the utilization of the medicinal plant and heterosis.METHOD:Hybridization combinations were selected by incomplete diallel cross design,randomized block design was used for field experiments,the botany characteristics were analyzed through field data investigations,and photosynthetic characteristics were measured using the LI-6400 portable photosynthesis measurement system.Determination of chemical constituents by High Performance Liquid Chromatography.RESULT:1.The analysis of the combining ability and Heterosis of the agronomic characters found that the General Combining Ability?GCA?effect of the parent A1 and B11 were the highest,and all the characters GCA were positive,the combination of A1×B8 has the highest specific combining ability?SCA?effect value,and the effect of single root weight is up to 12.07%;The results of heterosis analysis showed that the average values of super-parent heterosis,such as lateral root number,single root weight,and root diameter,were 47.37%,27.74%,and 11.25%,respectively;The results of heterosis analysis showed that the average values of super-parent heterosis was high,such as lateral roots number,single root weight,and roots diameter,were 47.37%,27.74%,and 11.25%,respectively;81.8%of the combinations with A1 have a higher Super parent advantage,indicating that the parent A1 has a good comprehensive trait.2.The analysis of heterosis and combining ability of the photosynthetic characteristics of Isatis indigotica lines revealed that there were significant differences in different photosynthetic indicators.they represented positive or negative two advantages,Among them,net photosynthetic rate and chlorophyll content have higher heterosis,The average heterosis of intercellular CO₂concentration,transpiration rate and stomatal conductance was negative;The net photosynthetic rate of the cross combinations with A1 as female parent had positive superior or super parent heterosis.A3 and B6 have higher GCA effect,and the combinations with higher SCA effect were A1×B3,A2×B6,A3×B7,etc.3.Heterosis analysis of chemical composition of Isatis indigotica inbred lines revealed that there were great differences in chemical composition among different cross combinations.The hybrid progeny showed positive or negative dominance.The average value of guanosine,?R,S?-goitrin,indigo and indirubin was positive,Among them,the average value of the?R,S?-goitrin mid-parent heterosis was 152.12%,and the mid-parent heterosis of uridine content was the smallest,which was-17.35%.guanosine,?R,S?-goitrin,indigo and indirubin were positive hyper parental advantages,Among them,the average value of?R,S?-goitrin content was the highest,reaching 45.18%.The results of the combining ability analysis showed that the chemical composition of the combination of parents A1 showed a higher SCA effect.Among them,the combination of A1×B7,A1×B10 and A3×B6 had 83.33%chemical indicators SCA all showed positive effects.CONCLUSION:1.Through the comprehensive analysis of the agronomic traits,photosynthetic characteri-stics and chemical composition content of Isatis indigotica inbred lines and the F₁ generati-on,the results showed that the majority of the characters of Isatis indigotica had obvious h-eterosis and conformed to the common natural phenomena in the biological field.2.Inbred lines A1,B2 and B6 have excellent comprehensive performance and great po-tential for breeding.They can be selected as follow-up breeding materials.3.Selecting the parents with high GCA effect to make the combination crosses,the gr-eater the chance to get the better F₁ generation of the target traits.In practice,breeding ma-terials can be selected according to the high value of their parents in different traits.4.The characters of the F₁ generation of Isatis indigotica showed different degree of h-eterosis,among which the Heterosis of root yield traits was more obvious,and the Heteros is of each character was greatly influenced by the mother parent.5.The Heterosis of the photosynthetic characteristics and chemical composition content of Isatis indigotica is complex and changeable.It is necessary to further analyze the other characters in order to choose according to the demand in the practical breeding.