| ‘Ziyan’tea plant is a newly bred high anthocyanin purple bud variety,its flowering quantity is particularly high,and the flowering period is longer.Tea plants are leafy plant,and their vigorous reproductive growth can have an inhibitory effect on nutritional growth.The study focused on the‘Ziyan’tea plant,investigating its flowering habits,understanding the basic rules of flowering and fruiting;Exploring the effects of artificial thinning and spraying chemical agents on thinning/inhibiting flowers,as well as their impact on fresh leaf yield and quality components,to determine the appropriate chemicals and concentrations,and to provide reference value for practical production applications.The research results are as follows:（1）The field investigation results of the flowering and fruiting characteristics of the‘Ziyan’tea plant were showed that in August 2022,the number of flower buds per plant of the11-12-year-old‘Ziyan’tea plant was about 3202,which was about 1.50 times that of other tea plant varieties.‘Ziyan’tea plant entered the initial flowering stage in late September,the peak flowering stage in mid-October,and the final flowering stage from late December to early January of the following year.The flowering period of‘Ziyan’tea plant is significantly longer than that of the national excellent variety‘Fuding Dabai Tea’（early November to early December）,and the flowering period of the purple variety‘Zijuan’（mid October to early December）.However,the yield per plant of the‘Ziyan’tea plant was the lowest.The fruit yield per plant of‘Ziyan’tea plant was about 7,while the fruit yield per plant of‘Fuding Dabai Tea’was 2.35 times that of‘Ziyan’,and the fruit yield per plant of‘Zijuan’was 2.00 times that of‘Ziyan’.（2）In summer,the artificial flower thinning treatment of‘Ziyan’tea plant showed that the flower thinning could promote the growth of new shoots,increase the yield of one bud and two leaves,and also increase the contents of water extract,tea polyphenols and theanine,and facilitate the accumulation of anthocyanins.The yield of‘Ziyan’tea plant was the highest after half of the bud was removed,which was 363.31 kg·hm-2,591.38 kg·hm-2 and 369.76 kg·hm-2in summer,autumn and spring of the following year,respectively,which increased by 28.55%,49.21%and 42.21%compared with the control（without bud removal）,respectively.The content of water extract was the highest when 1/2 treatment,which was 41.98%in summer,39.97%in autumn and 43.43%in spring of the following year,respectively,which were significantly higher than the control.The content of tea polyphenols in summer and autumn was the highest when all flower buds were removed,at 21.60%and 20.89%,respectively,which were significantly higher than the control;In the spring of the following year,the highest rate was 18.30%when 1/2 of the flower buds were removed,which was significantly higher than the control.Theanine content was the highest when 1/3 treatment,which was 6.44mg·g-1,6.29 mg·g-1 and 6.82 mg·g-1 in three seasons,respectively,which were significantly higher than the control.The anthocyanin content in summer and autumn was the highest when all flower buds were removed,with 4.05 mg·g-1 and 5.66 mg·g-1,respectively,significantly increasing by 23.10%and 11.42%compared to the control in the same season;And in the spring of the following year,the highest was observed when removing 1/2 of the flower buds,which was significantly increased by 21.68%compared to the control.（3）The effects of different concentrations of ethephon and prebulozole on‘Ziyan’tea plant was investigated.The results showed that the effects of different concentrations of ethephon and paclobutrazol on the‘Ziyan’tea plant varies.Within a certain concentration range,the higher the concentration of ethephon,the better the effect of thinning.After spraying ethrel at a concentration of 1400 mg·L-1 for 7 days,the flower dropping rate was 97.72%.Ethethylene could promote the growth of one bud and two leaves in the next spring,and the highest yield was 264.75 kg·hm-2 when the concentration was 1000 mg·L-1,which was significantly increased by 85.54%compared with the control.At the same tinme,ethephon was also beneficial to the accumulation of catechin components in one bud and two leaves of‘Ziyan’tea plant,When the concentration was 1000 mg·L-1,the contents of epigallocatechin and epigallocatechin gallate reached the highest,significantly increasing by 32.77%and 7.75%compared with the control,respectively.The concentration of paclobutrazol used in this experiment had no effect on flower thinning of‘Ziyan’tea plant.It can delay shoot growth and flowering process,but does not affect yield.At the same time,paclobutrazol significantly increased the anthocyanin content in one bud and two leaves of‘Ziyan’tea plant,which reached the highest value at 150 mg·L-1,reaching 3.77 mg·g-1,which was significantly increased by 29.55%compared to the control.After spraying ethephon and paclobutrazol,the‘Ziyan’tea plants would be stressed to some extent,but they would return to normal after spraying for 15 days.（4）The effects of different concentrations of gibberellin and 6-BA on tea plant of‘Ziyan’were investigated.The results showed that within a certain concentration range,gibberellin had dual effects on flower bud differentiation of‘Ziyan’tea plant,while 6-BA could inhibit flower bud differentiation.In April,50 mg·L-1 gibberellin promoted flower bud differentiation,but 100,200 and 300 mg·L-1 inhibited flower bud differentiation,with the lowest number of flower buds at 300 mg·L-1,which was significantly reduced by 61.47%compared to the control.At the same time,gibberellin could also increase the contents of anthocyanin and theanine in one bud and two leaves of the‘Ziyan’tea plant,and reached the highest levels at100 mg·L-1 and 300 mg·L-1,which were 3.00 mg·g-1 and 16.08 mg·g-1,respectively,significantly increased by 11.52%and 19.91%compared to the control,respectively.Within a certain concentration range,6-BA had inhibitory effect on the flower bud differentiation of the‘Ziyan’tea plant.When the concentration was 500 mg·L-1,the number of buds was the least,22.40 pcs·m-2,which was significantly reduced by 40.60%compared to the control.Meanwhile,6-BA could also increase the contents of tea polyphenols,EGCG and ECG in two leaves of one bud.And it reached the highest when its concentration was 500 mg·L-1,which was significantly higher than that of the control by 9.78%,12.20%and 12.28,respectively.In conclusion,in this experiment,1/2 bud removal in summer and 1000 mg·L-1 ethephon spray in autumn could significantly increase the yield of one-bud and two-leaf shoots of‘Ziyan’tea plant,and increase economic benefits.Spraying 100,200 and 300 mg·L-1 gibberellin and500 mg·L-1 6-BA after spring tea significantly reduced the buds of‘Ziyan’tea plant,and had little effect on the quality components of tea. |
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