| Camellia is an important woody edible oil tree species in southern China.Currently,the varieties of Camellia that are cultivated in China are mainly selected from ordinary natural Camellia plants.The large fruit,thin peel,and anthracnose-resistant varieties are difficult to development adaptability in modern Camellia industry.C.oleifera ’huashuo’ is a new large-yield variety,which belongs to flowering in autumn and winter seasons and high light efficiency and large fruit,but it is not strong against anthracnose;C.yuhsienensis Hu is an important wild relative of C.oleifera and has the advantages of flowering in spring,thin peel,high seed yield,high oil content,and resistance to Anthrax resistance.Gene transfer of superior traits from C.yuhsienensis Hu to C.oleifera ’huashuo’ is essential for improving the yield and quality.In this study,18 superior plants selected from the interspecific hybrid progeny of C.yuhsienensis Hu(YZ-2)× C.oleifera ’huashuo’(HS)are used as test materials.The three aspects of flower traits,photosynthetic characteristics and economic characters and nutritional components of fruits are compared and analyzed,with a view to laying the foundation for breeding excellent varieties with excellent parental traits and genetic improvement of Camellia.The main results are as follows:1.Study on the flower traits of the F1 generation of Camellia hybrids:18 different plants of F1 generation have obvious differences in three aspects:flowering phenology,floral traits and pollen quality.18 F1 generation plants have large coefficients of variation at the beginning of flowering.In 2017 and 2018,the coefficients of variation of the initial flowering period of different plants in the hybrids are 66.08%and 48.14%,respectively,and the maximum difference in flowering period between hybrids is about 50 days.The results of cluster analysis showed that the flowering dates of different plants of 18 hybrids are divided into 4 types.The flowering period of Camellia F1 generation is mostly of type Ⅱ and Ⅱ,and enters the flowering period in November.The flowering period of the hybrids of Camellia tends to or tends to the parent of late flowering period.The flowering period of the hybrids of Camellia is mostly autumn and winter flower types and winter flower types.It is similar to HS and enters the initial flowering period in late October;YH-1,YH-5,YH-9,YH-11,YH-14,YH-16 and YH-17 belong to Ⅲ type,and enter the flowering period in mid and late November;YH-6 belongs to the Ⅳ type,and enters the flowering period in mid-December;The floral traits of 18 hybrids F1 generation plants are significantly different,and the coefficient of variation of some floral organ traits are greater than 20%,and there are extensive separation.The number of stamens,styles/ventricular,pistil height,ovule number,and stamen group height among the 18 hybrids are all between the parents,showing a clear mid-parent advantage.There are super-individual individuals in the flower diameter and petal number,showing a positive mid-parent advantage.The average value of the ovules of the 18 hybrids is 19.65,which is significantly less than HS and greater than YZ-2.The five hybrids with the largest number of ovules are YH-10,YH-11,YH-15,YH-16 and YH-18,and the range is 22～25;The pollen quantity and vigor of the 18 hybrids are widely separated;the pollen quantity of the progenies presents a super-parent advantage,while the pollen vigor presents a low-parent advantage.Among them,the amount of pollen in the single anther of the hybrids range from 880.0 to 10857.2,the average value is 5771.0,and the Heterosis Index is 183.4%,showing a clear superparent advantage;while the pollen vigor of the hybrids are distributed between 10.82%and 71.69%,The Heterosis Index is 86.49%,which showes a negative mid-parent dominance compared with the parents,while the pollen vigor of YH-2,YH-11,YH-12 and YH-13 are less than 20%.In addition,the F1 generation pollen of 18 hybrids all had "pseudo-pollen".Both agar culture method and Alexander staining method indicate that "pseudo-pollen" do not function as a male gametophyte of Camellia.It is necessary to remove the "pseudo-pollen".2.Studies on the photosynthetic characteristics of F1 generation of Camellia hybrids:YZ-2 and HS have high photosynthetic efficiency,the net photosynthetic rate(Pn)is 9.26 μmolm-2s-1 and 7.95 μmolm-2s-1,respectively,and the average value of Pn of hybrids is 7.09 μmolm-2s-1,Heterosis Index is 82.39%,indicating that the photosynthetic characteristics of the 18 progenies showed a negative low-parent dominance.The photosynthetic characteristics of the offspring are abundant variations,and the coefficient of variation is 33.87%.Among them,YH-10,YH-15,YH-17 and YH-9 have high photosynthetic efficiency,and their Pn are 10.26 μmolm-2s-1,10.15μmol·m-2s-1,9.97 μmolm-2s-1 and 9.17 μmolm-2s-1,respectively,with high light efficiency,significantly higher than the parent.Through correlation analysis,it is found that the net photosynthetic rate(Pn)of the hybrids has no significant correlation with chlorophyll content;Pn has significant or extremely significant positive correlations with parameters such as leaf length,leaf width,and leaf area,and the correlation coefficients are 0.372,0.347,and 0.343,respectively.3.Studies on the economic and quality traits of fruit of the F1 generation of Camellia hybrids:The single fruit weight,horizontal diameter and vertical diameter of YH-15 are significantly higher than those of the parents and other hybrid progeny.The average single fruit weight is 74.02 g;the thinnest peel thickness of the three hybrid progeny are YH-9,YH-10 and YH-5,and their peel thickness are 1.72 mm,1.77 mm and 1.96mm respectively;YH-10 has the highest fresh seed rate and dry seed rate,respectively 62.05%and 34.61%,YH-15 fresh seed rate is 60.92%after YH-10.The main economic traits of the fruit have a hybrid dominance index of less than 100%,showing a negative mid-parent or negative low-parent advantage;The quality traits of fruit in Camellia hybrids is significantly different.The coefficient of variation of the functional nutrients of the interbreeding between YZ-2 and HS species is large,of which the total phenol and squalene are 94.50%and 48.47%,respectively,and the content of total phenol varies from 5.13 mg/kg to 53.36 mg/kg,and the top two hybrids are YH-9 and YH-7,respectively,which are larger than the parents and other hybrids.,which the total phenol content is 43.44 mg/kg and 53.36 mg/kg;the squalene content varies from 190.1 mg/kg to 721.7 mg/kg,and the squalene content of YH-17,YH-11,YH-12,YH-15,YH-7 and YH-6 in the hybrids is 721.7 mg/kg,653.1 mg/kg,569.1 mg/kg,360 mg/kg,385.1 mg/kg and 359.7 mg/kg,respectively,higher than the parents and other hybrids;The coefficient of variation of oleic acid in fatty acid composition is 3.26%,with a variation range of 74.39%to 82.94%;the coefficient of variation of polyunsaturated fatty acids(linoleic acid and linolenic acid)is 25.03%.The main economic traits of the fruits of the hybrid progeny,and most of the traits of fatty acid components and functional nutrients show mid-parent advantages or super-parent advantages,such as stearic acid,oleic acid,linolenic acid,cis 11-eicosine in fatty acid components.Heterosis Index of enoic acid,total unsaturated fatty acid and monounsaturated fat are 125.16%,101.65%,116.42%,109.89%.100.75%and 101.69%respectively;α-tocopherol,total phenol and horn in functional nutrition Squalene,the Heterosis Index is 106.86%,140.39%and 135.31%,respectively,and the quality of the oil is excellent;The cumulative contribution rate of the four principal components extracted by the principal component analysis method reaches 84.44%.The comprehensive evaluation results show that YH-15 has the best overall performance,followed by HS.YH-15 is characterized by large fruit,thin skin,high fresh seed rate,high unsaturated fatty acids,high α-tocopherol and high β-sitosterol. 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