Comparative Study On Fruit And Seed Development Of 4 Camellia Oleifera Cultivars

Camellia oleifera Abel is an evergreen tree of the Camellia genus of theaceae,widely distributed in the hilly areas of southern China.In this paper,four main cultivars of Camellia oleifera Huashuo,Huajin,Huaxin and XLC15 are used as research materials.Comparative study of flowering period,fruit setting rate,seed development process,oil content,fatty acid composition,oil body,and transcriptome sequencing for HS and HJ seeds,in order to accurately grasp the flowering and fruit setting characteristics of these 4 main cultivars The law of oil transformation and the mechanism of seed maturity provide a scientific basis for cultivar allocation and the establishment of high-quality and high-yield cultivation measures,and lay a solid foundation for the determination of the optimal harvest time.The main results are as follows:1.The flowering period of the four Camellia oleifera cultivars was investigated and artificial pollination was used to study the fruit setting characteristics of the four pollination combinations(C.Huashuo x C.Huaxin,C.Huashuo x C.Huajin,C.Huashuo x C.XLC15,and C.Huaxin x C.Huashuo).The results are as follows:These 4 cultivars duration of the full flowering period is about 20 days.The C.Huajin and C Huaxin flowering periods overlap the longest,and the C.Huashuo and XLC15 flowering periods overlap the longest.The four pollination combinations have two fruit drop peaks,which are 3-15 and 25-43 weeks after pollination.After harvesting camellia oleifera and statistical analysis,it was found that the fruit set rate of 3 weeks after pollination of the four pollination combinations were 84.52,83.70,81.25,and 94.00%.So C.Huajin and C.Huaxin can be pollination trees for each other,and C.XLC15 can be C.Huashuo pollination trees.2.The research of paraffin section in the early stage of seed development found that the development of Camellia oleifera seeds during the period of March to May mainly focused on the development of endosperm and the expansion of the seed coat,and the emergence and development of seed kernels from June to August.Seeds have not yet begun to develop in March and kernels do not appear until early July,which may be the cause of the late maturity of C.Huashuo.3.Statistical analysis was performed on 4 Camellia oleifera cultivars,2 fruit shape indexes and 12 economic traits indicators,and the results are as follows:The fruits of the 4 cultivars all grew rapidly from March,and the C.Huashuo vertical diameter growth ended in mid-September,the first time The high-speed growth of the horizontal path ends in mid-August,and the second high-speed growth period of the horizontal path ends in early October to early November;the high-speed growth of the vertical path of HJ ends in early July,and the high-speed growth of the horizontal path ends in mid-August;C.Huaxin and C.XLC15 vertical Both the rapid growth of diameter and transverse diameter ended in early August.The fresh seed weight,fresh kernel weight,fresh seed yield and fresh seed yield of the four cultivars basically showed a trend of first increase and then decrease(except for the C.Huashuo fresh seed weight,which continued to rise).Dry seed weight,dry kernel weight and dry seed yield,kernel rate is showing a continuous upward trend.Comparing the mature economic traits of the four cultivars,C.Huashuo single fruit weight,dry seed weight and peel dry weight were the largest,while C.Huajin dry kernel weight,dry seed yield,dry seed yield and hundred seed weight were the largest.4.A study of three internal nutrients of 4 Camellia oleifera cultivars of seeds found that the soluble protein content in the seeds had a dynamic balance in the early stage,HS gradually increased in mid-September,C.Huajin began to gradually increase in mid-August,and C.Huaxin and C.XLC15 increased in 9 The beginning of the month gradually increased;the soluble sugar content increased first and then decreased,C.Huajin and C.Huaxin peaked in mid-July,C.XLC15 peaked in early August,and C.Huashuo peaked in mid-August;starch content increased first and then decreased.Trends,C.Huajin and C.Huaxin peaked in early July,while C.Huashuo and C.XLC15 peaked in mid-July.5.Analysis of oil content and fatty acid composition in three parts of 4 Camellia oleifera cultivars fruits.The peak oil and fat synthesis of C.Huashuo,HJ,C.Huaxin and C.XLC15 were in mid-September to early November,mid-August to mid-October,and early September to 10 Mid-month and early September to early November.Comparing the oil content of fruit in each part of the four cultivars,it was found that HJ seed oil rate and fruit oil rate was the highest,and C.Huaxin kernel oil rate was the highest.Analysis of fatty acid composition found that oleic acid was the most important fatty acid synthesized during the synthesis of fats and oils.6.Observing the oil body using laser confocal microscopy and transmission electron microscopy,the results are as follows:The oil body is approximately spherical,and when it starts to form,it gathers around the cell wall,slowly accumulates and diffuses into the interior until it is full of cells.section.C.Huashuo and C.XLC15 have not appeared oil bodies in mid-July,while C.Huajin and C.Huaxin have appeared.By mid-October,HJ oil bodies have basically filled the whole cells,C.Huaxin oil bodies have filled more than 90%of the entire cells,but the number of XLC15 oil bodies Less than 50%of the whole cell is filled,and C.Huashuo is even less,only about 30-40%.7.Using Illuminna RNA-Seq technology,successfully obtained transcriptome sequence information of C.Huajin(A1)and C.Huashuo(B1)seeds at different developmental stages.Analysis revealed that:A1-B1,A2-B2,A3-B3,and A4-B4,respectively There were 2315,3551,1869,and 618 genes that were up-regulated,and there were 3322,1948,1295,and 696 genes that were down-regulated.Through KEGG pathway analysis,the major fatty acid biosynthetic pathways involved in lipid synthesis and metabolism were screened:unsaturated fatty acid biosynthesis,?-linolenic acid metabolism,fatty acid biosynthesis,fatty acid degradation,fatty acid elongation,linoleic acid metabolism,glycerolipid metabolism,arachidonic acid metabolism and glycerophospholipid metabolism.Among them,there are 26 genes enriched in fatty acid biosynthesis pathways,which are classified into 9 gene families.In the early stage of oil synthesis,there are many significantly different genes in 'Huajin' and 'ASUS'.,Differential genes gradually decreased.In addition,the expression levels of 9 gene families of 'ASUS' were significantly lower than those of 'Huajin' in the initial stage of oil synthesis.