Effects Of CTK And Other Hormones On Growth And PSⅡ Light Absorption And Utilization In Tomato Reprovetive Organ

According to the problem of small fruit rate and barren fruit rate on the high side in greenhouse tomato, the effects of on PSⅡlight absorption and utilization of plant growth regulators on the surface of tomato ovary and fruit were studied in red xylocarp tomato'Bobcat'. A floral bud and young fruit were respectively sprayed with cytokinin (CTK), Brassinolide(BR) and Gibberellin( GA3).In the process of growth,we were determined the size of tomato bud,ovary and fruit.When the fruit ripening, we were determined the quality of fruit . Chlorophyll fluorescence kinetics parameters of tomato ovary and fruit surface were measured by chlorophyll fluorescence spectrometer (MINI-IMAGING- PAM).1. The floral buds were respectively sprayed with 600,800,1000mg·L-1 CTK,350μl·L-1BR,50mg·L-1GA3,800mg·L-1CTK+350μl·L-1BR,800mg·L-1CTK+50mg·L-1GA3. The results indicated that 600mg·L-1 CTK was beneficial to increase the transverse diameter and vertical length of the bud. The effect of enlargement on the transverse diameter and vertical length of the bud spraying compound hormone were not obvious.2. 800mg·L-1 CTK was beneficial to increase the transverse diameter and vertical length of the fruit. After 28 d treatment, transverse diameter and vertical length of the fruit spraying 800mg·L-1 CTK were7.2cm,6.9cm, transverse diameter and vertical length of the control were 6.3 cm,5.5 cm.They were up by14.3percent and25.4 percent than the control respectively.The fruits spraying800mg·L-1 CTK of signle fruit weight,soluble solids and handress respectively were 226.018g,4.9%,6.6kg·cm-2at fruit maturation period.The control of signle fruit weight,soluble solids and handress respectively were166.94g,3.9%,4.03kg·cm-2. They were up by 35 percent,26 percent and 64 percent than the control respectively. The effect of enlargement on the transverse diameter,vertical length,signle fruit weight,soluble solids and handress of the fruit spraying compound hormones were not obvious.3. Maximal photochemical efficiency of PSⅡin the dark (Fv/Fm)of the ovary,stigma,anther and sepal respectively were 0.756,0.766,0.769,0.766 in the bud stage.In the florescence, Fv/Fmof the ovary,stigma,anther and sepal respectively were0.668,0.754,0,0.789. Actual light quantum yield of PSⅡ(Y(Ⅱ))and photochemical quench(qP) of the ovary,stigma,anther and sepal of size order were sepal>stigma>ovary>anther in the bud stage and the florescence.Non-photochemical quench(qN) of the ovary,stigma,anther and sepal of size order were anther >sepal>stigma>ovary in the bud stage, qN of the anther was decreased to 0 in the florescence.Fv/Fm,Y(Ⅱ),qP,qN of the fruit respectively were 0.764,0.461,0.710,0.537. Fv/Fm,Y(Ⅱ),qP,qN of the sepal respectively were 0.773,0.525,0.765,0.439. Fv/Fm,Y(Ⅱ),qPof the sepal more than that fruit,and qN of the sepal lower than that fruit.4.The ovarys were respectively sprayed with 600,800,1000mg·L-1 CTK,350μl·L-1BR,50mg·L-1GA3,800mg·L-1CTK+350μl·L-1B,800mg·L-1CTK+50mg·L-1 GA3.CTK600mg·L-1can maintain high levers in Fv/Fm, Fv'/Fm',Y(Ⅱ),qPof the ovary,and qNof the ovary was reduced. The effect of fluorescence kinetics parameters of the ovary spraying compound hormones was not obvious. CTK800mg·L-1can maintain high levers in Fv/Fm, Fv'/Fm',Y(Ⅱ),qPof the fruit, and qNof the fruit was reduced. The effect of fluorescence kinetics parameters of the fruit spraying compound hormones were not obvious.5. A floral bud at the 7 d before flowering or a fruit at the 10 d after flowering was respectively sprayed with 600 and 800 mg·L-1 CTK. The CTK significantly promoted expansion of ovary and fruit. However, the vertical length of ovary of spraying the floral bud with 600 mg·L-1 CTK was obviously superior to 800 mg·L-1 CTK, and vertical length of fruit of spraying the fruit with 800 mg·L-1 CTK was obviously superior to 600 mg·L-1 CTK. The absorption coefficient (Abs) on the surface of the ovary could be in higher levers with 600 mg·L-1 CTK than 800 mg·L-1 CTK, but the Abs on the surface of the fruit could be in higher levels with 800 mg·L-1 CTK than 600 mg·L-1 CTK. With the development of ovary and fruit, the maximum quantum yield of primary photochemistry of photosystemⅡ(Fv/Fm),original quantum efficiencies (Q) and maximum electron transfer rate (ETRmax) decreased gradually, while the qN increased gradually. The CTK increased light absorption and utilization of ovary and fruit, which promoted the growth and development of fruit.