Genetic Variation Analyze Of Leaf Phenotype And Main Biochemical Traits In Interspecific Hybridization Of Tea

Tea plant is the most valuable group in the Camellia plant.The study of tea plant hybridization mainly focuses on the different cultivated varieties within the Camellia sinensis(L.)O.Ktze,but the study of different species within the tea group,or the study of distant hybridization between the tea group and other subordinate species of camellia is very little.Camellia sinensis cv.Jinxuan and Camellia ptilophylla Chang are two different species in tea group.Their historical origin,geographical distribution,morphological characteristics,biochemical characteristics,genetic material basis and purine and alkali metabolism pathway are quite different.In this paper,Camellia sinensis cv.Jinxuan(♀)、Camellia ptilophylla Chang(♂)and its distant hybridization breeding F1 progeny of 66 full-sib tea plant were studied,based on the establishment of HPLC method,the genetic variation of leaf phenotype and main biochemical traits of distant hybridization of tea was studied and analyzed,which laid a good foundation for further study on the m olecular mechanism of genetic variation of the population of distant hybrid parents and F1 progeny.The main results are as follows:(1)The variation coefficient of the 17 phenotypic traits were between 8.33% to 49.02%,the genetic diversity index of them were between 0.18 to 1.61.Most of traits in F1 progeny were negative dominant inheritance,and the relative heritability index a1 of 17 traits up to 0.85,the minimum is only 0.09.The relative heritability index of male parent was higher in 7 phenotypic traits such as young shoot color,and the female parent was higher in 8 phenotypic traits such as young shoot pubescence.The mid-parent heterosis rate of 14 traits in this distant hybridization ranged from-38.00% to 23.33%,among them,11 were negative and 3 were positive.The negative extraparent segregation existed in the trait of leaf width and leaf vein,and the positive extra-parent segregation existed in the trait of leaf apex.(2)Based on Agilent 1260 high performance liquid chromatography,Agilent Eclipse XDB-C18(4.6×150nm,5μm)column,0.1% trifluoroacetic acid ultrapure water solution(A)and pure methanol(B)were used as mobile phase:A HPLC method for the simultaneous determination of gallic acid(GA)and eight catechins(GC、EGC、C、EGCG、EC、GCG、ECG、CG)within 45 minutes in tea was established: The elution gradient was 0 ~ 30 min,90% ~ 70% A;30 ~ 40 min,70% ~ 20% A;40.1 ~ 45 min,90%A.The column temperature was 38℃,the injection volume was 10 μ L,the flow rate was 0.8m L/min,and the detection wavelength was 278nm;A HPLC method for the simultaneous determination of Theobromine(TBR),Theophylline(TP),Theacrine(TC),and Caffeine(CAF)within 40 minutes in tea was established: The elution gradient was 0 ~ 20 min,90% A;20 ~ 30 min,90% ~ 80% A;30 ~ 35 min,80% ~ 20% A;35 ~ 35.1min,20% ~ 90%A;35.1 ~ 40 min,90%A.The column temperature is 38 ℃,the injection volume is 10 μ L,the flow rate is 1.0m L/min,and the detection wavelength is 230 nm.(3)The variation coefficient in F1 progeny of 4 caffeine and theobromine indexes were between 20.02% to 51.54%.There was a highly positive correlation between the biochemical traits,multiple significant linear regression model can be obtained.The F1 progeny of 64 full-sib tea plant were divided into four groups,among whi ch the first group included 28 F1 plants such as N09,the second group included 15 F1 plants such as Camellia sinensis cv.Jinxuan(♀)and N20,the third group included 21 F1 plants such as N52,and the Camellia ptilophylla Chang(♂)itself aggregated into the fourth group.By principal component analysis of gallic acid and 7 catechins,three principal components were extracted,and F1 progeny catechin comprehensive score were ranked.(4)On the relative heritability of parents,5 biochemical indexes showed positive dominance,3 biochemical indexes showed negative dominance;On the heterosis of F1 progeny,5 biochemical indexes showed positive mid-parent advantage,3 biochemical indexes showed negative mid-parent advantage,7 biochemical indexes showed positive extra-parent segregation,1 biochemical index showed negative extraparent segregation.