Establishment Of Regeneration System Of Tea Plant(Camellia Gymnogyna) And Effect Of Red Light On Adventitious Root Differentiation

Tea Plant?Camellia gymnogyna?is a perennial tree of the genus Camellia of Theaceae,which belongs to a rare variety of ancient plant tea.Therefore,the establishment of tea plant?Camellia gymnogyna?regeneration system is of great significance for the resources preservation,seeding propagation and application of tea plant.In this study,tea plant explant was used as material to screen its primary culture system,subculture system and rooting culture system,and an efficient in vitro regeneration system was established.At the same time,the effect of red light on adventitious root differentiation was studied by giving different culture conditions of red light and a white light at the rooting stage.The results of this paper are as follows:1.The establishment of regeneration system of tea plant?Camellia gymnogyna??1?The effects of one-step disinfection and two-step disinfection on explant contamination rate and browning rate were compared in the primary culture of axillary buds.At the same time,the effects of hormone types and concentrations on axillary bud germination were studied.The results show that the two-step disinfection method is better than the one-step disinfection method.75%alcohol disinfection for 30s,then 0.1 liter of mercury for 4 minutes,2 time of sterile water rinsing,0.1%liter of mercury disinfection2min and finally 4 time of sterile water washing is the optimal disinfection system.After disinfection,the best medium for axillary bud germination of explants is MS+1.5 mg/L6BA+0.5 mg/L NAA,the germination rate of axillary buds is 50%.?2?The effects of different hormone combinations such as hormone type,concentration and ratio of the proliferation of adventitious buds of tea plant were investigated in the culture of adventitious bud proliferation.The results showed that GA₃had the greatest effect on the proliferation of adventitious buds,and the best condition for adventitious bud proliferation was MS+1.0 mg/L 6-BA+0.5 mg/L NAA+2.0 mg/L GA₃.?3?The rooting medium was used to study the effects of different hormone combinations,such as hormone type,concentration and ratio,on the rooting rate of tea plant.The results show that the best rooting medium of tea plant is 1/2 MS+IBA 1.0mg/L+IAA2.0 mg/L+0.1%activated carbon,and the rooting rate can reach more than63.4%.2.Effect of red light on adventitious root differentiation?1?Effect of red light on adventitious root rate and root quality of tea plant during the rooting induction period,the effects of red light and white light on rooting rate and root quality were compared.The results showed that red light could significantly increase the rooting rate of tea plant.After 36 days of culture,the rooting rate of tea plant under red light was 81.7%,that of tea plant under white light was 56.6%,and the rooting rate of red light was 25%higher than that of white light.At the same time,the observation of adventitious root development showed that red light culture was better than red light culture,the average number of rooting was 12.80 under red light and 7.50 under white light,the average maximum root length was 1.46 cm in red light,0.48 cm in white light,0.74 cm in red light and 0.22 cm in white light.?2?Observation on the development period and type of adventitious root of tea plant under red light by using paraffin section technique,the tissue microscopic observation on the base of stem segment of tissue culture seedling was carried out.The results showed that there was no primary root primordium in the stem of tea plant before rooting.The rooting type belongs to induced rooting.The root base of adventitious root of tea plant is mainly formed by parenchyma cells and vascular cambium at the junction of pith ray and subcortex.3.Effect of red right on endogenous hormones during adventitious root development of tea plant?Camellia gymnogyna?Sampling of stem segments at different developmental stages under red and white light,the changes of IAA,IBA,GA₃,ZT and other hormones in each stage were measured by high performance liquid chromatography?HPLC?.The results showed that different hormones showed different trends in different developmental stages after red light treatment of tea plant tissue culture seedlings.Among them,IAA and GA₃ are most closely related to adventitious roots.4.A preliminary study on the transcription of adventitious roots development in tea plantThrough the sampling of stem segments at different developmental stages under red and white light,the differentially expressed genes were analyzed by high-throughput sequencing technique.The results showed that.The items of GO enrichment are mainly concentrated in the functional items such as redox process,protein phosphorylation process,transcriptional regulation process,transmembrane transport process,carbohydrate metabolism,auxin response and so on.KEGG metabolic pathway analysis showed that these genes were mainly enriched in some metabolic processes,such as amino sugar and nucleotide sugar metabolism,pentose phosphate pathway,mutual transformation of pentose and glucuronates,zeatin biosynthesis,?-linolenic acid metabolism and so on.