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Study on Effects and Mechanism of PGRs on the Growth of Several Flowers

In the course of the modernization production of flowers, because plugseedlings are adopt, the excessive growth of the flowers is a very seriousproblem. It is a kind of simple and convenient method with instant effect touse plant growth retardants (PGRs) to control the physiology growth offlowers. As to this, already there have been many studies done at home andabroad. But because of different horticultural equipments,environmentalcondition and cultural modes between areas, it is different that the results ofthe studies applies to China directly. So it is significant for improvement ofquality of plug seedlings and advance of industrialization of seedling to studythe physiological effects of PGRs on plug seedlings pertinently andsystematically.For this reason, this thesis selected Brassica (Brassica oleracea var.Acephala), Salvia (Salvia splendens Ker. -Gawl.), Petunia (Petunia hybridaVilm), marigold (Tagetes erecta L.) and maidenhair (Tagetes patula L.),several kinds of herbaceous flowers used widely, as test materials, studied theretardant effects of different concentration of daminozide (B9), chlormequat(CCC ) and paclobutrazol (PP333 ) , the three PGRs, and identified the bestconcentration and mixed proportion. The mechanism of dwarfing maidenhairusing paclobutrazol was investigated from several aspects such as shape,anatomies configuration, physiology, endogenous hormones and so on. Theresult shows:(1) The plug seedlings of Salvia are treated with chlormequat (CCC) ofdifferent concentrations by spraying. 0.02% CCC is optimal concentration.(2) The plug seedlings of Petunia are treated with B9, CCC and solutionmade up of B9 and CCC of different concentrations by spraying. Theireffective and safe concentrations are 1000~2500 mg/L B9, 0.05%~0.3% CCCand 1500 mg/L B9+0.3% CCC respectively. And their optimal concentrationsare 2500 mg/L B9, 0.3% CCC and 1500 mg/L B9+0.3% CCC respectively.Among the three optimal concentrations, effect of 1500 mg/L B9+0.3%CCCis the best and that of 0.3% CCC takes second place. But the price of 2500mg/L B9 is the lowest. When the concentration of CCC is beyond 1%, thephytotoxicity of CCC on the plants will happen. (3) The plug seedlings of marigold are treated with B9, CCC, solutionmade up of B9 and CCC, and PP333 of different concentrations by spraying.Their effective and safe concentrations are 1000~2500 mg/L B9, 0.1% ~0.3%CCC, 1000 mg/L B9+0.2%CCC and 10~60 mg/L PP333 respectively. Andtheir optimal concentrations are 2500 mg/L B9、0.3%CCC、1000 mg/L B9+0.2% CCC 和60 mg/L PP333 respectively. Among the four optimalconcentrations, effect of 60 mg/L PP333 is the best, that of 1000mg/L B9+0.2% CCC takes second place and that of 0.3%CCC takes third place. Morever,the price of 60 mg/L PP333 is the lowest. When the concentration of CCC isbeyond 1%, the phytotoxicity of CCC on the plants will happen. (4) The plug seedlings of maidenhair are treated with PP333 of differentconcentrations by spraying in different periods. Their effective and safeconcentrations are 10~30 mg/L in pre-emergence, 30 mg/L in the stage ofcotyledon, 10~60 mg/L in the stage of one pair of leaves and 15~60 mg/L inthe stage of two pairs of leaves. Among of them, the optimal treatment is 30mg/L in pre-emergence. As far as plant height is concerned, the earlier theplants are treated, the more observable the effect of PP333 is. The phytotoxicityof PP333 on the plants will happen when the concentration of PP333 is beyond60mg/L in the stage of pre-emergence and cotyledon, and beyond 120 mg/L inthe stage of one pair of leaves. The concentrations of PGRs mentioned previously can control the heightof the plants effectively and safely. They are effective in reducing the height ofthe plants, increasing the thickness of leaves, increasing the content ofchlorophyll, making the leaf color darker, and effectively improve theappreciative value of the flowers. The higher the concentrations of PGRs are,the more effective they are. (5) Spraying 30 mg/L PP333 in pre-emergence can decrease the content of

Effects of Plant Growth Retardants on Dwarfing of Lawn Grasses Gramineae

Plant growth retardants (PGRs) can cause dwarfing of Plants. They can be used for inhibiting growth of lawn grasses, and thus reducing the number of mowing However, the effect will not be satisfactory if they are not applied properly. In this study, the effects of four PGRs on growth rate and quality of the two lawn species Bermudan grass (C.dactylon×C.transvadlensis) and ryegrass (Lolium perenne L.) at different concentrations were investigated. The results obtained Showed:1. The four PGRs were different in effect, with uniconazole having the strongest effect on dwarfing of Bermudan grass and ryegrass, B9 having no obvious effect, chlormequat and mepiquat chloride being intermediate.2. The effect of the same PGR varied with the concentration used. Uniconazole at 50mg/L, chlormequqt at 1000mg/L, and mepiquat chloride at 1000mg/L were the optimum concentration for spraying according to combined coordination of dwarfing effects and economic and ecological benefits.3. The PGRs influenced growth of the lawn species mainly by (1) retarding growth and thus reducing mowing; (2) promoting tillering and thus increasing plant densities; (3) elevating the content lf chlorophyll in leaves and thus prolonging duration of green leaves, and (4) increasing the ratio of roots to shoots and thus improving creeping growth.4. The optimum stage for application of the PGRs was the vigorous grow stage of the grassed. The satisfactory results could be achieved when the warm-seasoned grasses were treated from June to July and the cool-seasoned grasses from April to May or from September to October.5. The duration of effects of the PGRs varied with the PGRs and their concentrations used, times of spraying, grass species and the local climate. In this study, the effect of PGRs is in 40-60 days.6. Use of PGRs will lower the cost by reducing mowing and fertilization, which will bring about a remarkable economic return when applied right in lawn management.

Studies on the Regulation of Florescence of Phalaneopsis ssp. in Beijing Area

The study based on the pot-flower Phalaenopsis production in Beijing. The plant growth retardants, the fertilizers of forcing and the temperature control before forcing and GA3 were used in the flowering regulation of Phalaenopsis. Results are as follows:1) Effect of plant growth retardants: Three different concentrations of plant growth retardants(PP333、B9、CCC) made the first flower anthesis of Phalaenopsis‘45#’earlier than the contrast, and the difference was very significant. But for the cultivars‘9005′and‘F3′, the effect was inverse, and the difference was significant. The effects on the height of flower stalk, number of flowers and the diameter of single flower were all inhibited by the three plant growth retardants. The inhibiting effects were stronger with the increase of concentration.2) The experiment of different fertilizer N-P-K ratio for forcing indicated : The prescription 2(N:P2O5:K2O=9:45:15 )was better for forcing than ratio 1(N:P2O5:K2O =10:30:20) and ratio 3(N:P2O5:K2O =0:30:20). Ratio 2 and 1 all made the first flower anthesis earlier, the height of flower stalk higher, the flowers number more and the flowers diameter greater. Ratio 3 was the worst for the flower induction. It made initial the first flower anthesis indistinctively earlier, but inhibited the height of flower stalk, the number and the diameter of flowers by some extent.3) Result of experiment with GA3+6-BA: The length and diameter of flower stalk, the number and the diameter of flowers were better than the contrast and other treatments by once daubing the second node (from bottom to top ) of Palaenopsis‘45#’、‘9005′、‘B-2′with GA3+6-BA. Only once daubing the second node of‘9005′with GA3 (20、40、60、80、100mg/L ): The result showed that 80mg/L was the best concentration. The number of flowers, the height and diameter of flower stalk were significant great better than the contrast and other treatments, and the diameter of flowers was indistinctive than other concentrations.4) The experiment of temperature control before forcing indicated: To the cultivar Palaenopsis‘53#’, the time of low temperature(20~23/16~18℃) lasted longer, the flower bud appeared later in the forcing period. The result under high temperature (26~29/20~21℃)was inverse. The first flower anthesis was 30 days treatment under the low temperature, then was 45-days and 60-days . Under high temperature the first flower anthesis was 45-days, the second was 60-days and the latest was 30-days. But under the condition of low temperature, the quality of inthe first flower anthesis (the number of flowers, the height and diameter of flower stalk, and the number and diameter of flower ) related to the time of the two treatments. The longer time of the treatment, the better quality of the inflorescence

The Effect of Plant Growth Retardant on Amaranthus, Hydrangea and Chrysanthemum

In the course of the modernization production of garden plants, how to control the growth is a serious problem.In modern times, with the developing of landscape, the garden plants were raised higher level for fill the market requirements. So, How to control high and figure of plants to suffice the market is a problem.High, size of flower, length of florescence and some other characters were controlled by DNA. But now , there are three ways to control the characters. First ways, to select individual plant which have some characters in several generation and breed it to gain the excellent offspring; the second , to change the DNA of the plant, and gain some excellent character plants; the third , to use plant growth retardant to control the physiology growth of plants.The advantage of first ways – - all characters which gained by choice and breed are transmissibility. We can obtain a good deal of plants which have same character. But the process is too long, and need a large numbers of plants. Second ways is a powerful method to change the characters, but this method is exorbitant and always used on grain and cash crops. On the production of landscape plant, to control the plant characters by plant growth retardant is a befitting method. It’s simple and economical.Experiments and researches prove that, three plant growth retardant–daminozide (B9), chlormequat (CCC), paclobutrazol (PP333) can control the characters of plant. They were influence landscape plants on several aspects such as shape, anatomies configuration, physiology and so on. It is a kind of simple and convenient method with instant effect to use plant growth retardant to control the physiology growth of plants. As to this, already there have been many experiments and studies done at home and abroad. But, because of different horticultural equipments, environmental, condition and cultural modes between areas, it is different to apply those findings to Chongqing directly. So it is significant for improvement of quality of plants and advance of industrialization of plants to study the physiological effects of plant growth retardant on landscape plants pertinently and systematically.In this thesis, Amaranthus (Amaranthus tricolor var splendens. Hort., Hydrangea (Hydrangea macrophylla Ser.), and chrysanthemum (Dendranthema marifolium Tzvel.) which used widely in landscape were choose for experiment material.The result of experiment shows: 1) Amaranthus are treated with daminozide(B9), chlormequat(CCC), paclobutrazol(PP333) on three different concentration. Standard approach to use standard in landscape, daminozide(B9) 1000 mg/L is optimal concentration. This concentration can control the height of plants steadily. But in other aspect, paclobutrazol(PP333) 800 mg/L can make the flower have more excellent appearance. Chlormequat (CCC) 100mg/L~200mg/L can help plants fight back adversity, the survival of plant is uprated. Taking one with another, in this experiment paclobutrazol(PP333) is the best optimal plant growth retardant, and 400~600mg/L is the optimal concentration.2) Hydrangea are treated with daminozide(B9) ,chlormequat(CCC), paclobutrazol(PP333) of three different concentrations by spraying. Standard approach to use standard in landscape, Paclobutrazol(PP333) have stronger reaction than others, But daminozide(B9) is the best optimal plant growth retardant on Hydrangea, Because it can control height and flower steadily and safely. And 1000~2000mg/L is the optimal C. When the concentration is beyond suited, the phytotoxicity of medicament on the plants will happen.3) For chrysanthemum ‘Shan cheng zhi guang’, Paclobutrazol(PP333) can control the height effectively. Daminozide(B9) 2000 mg/L is effective in reducing the height of the plants, making the leaf color darker and making the flower more bigger and more darker. When the concentration between 1000 mg/L to 2000 mg/L, the increase of flower’s length is obvious. Spraying Chlormequat(CCC) and paclobutrazol(PP333) can delay florescence. Spraying same plant growth retardant with same concentration on different variety of chrysanthemum, it put up different refection.More and more studies on the plant growth retardant is compulsory work for apply optimal concentration on production of landscape plants.

The Influence of Applying Nitrogen and Plant Growth Retardant on Growth of Turfgrass

This paper aimed at the current management of turf mowing and fertilization in theturf maintenance. The research chose cold season turfgrass Kentucky bluegrass (Poapratensis L.), as the test materials, investigating the effect of plant growth retardant Primo(Trinexapac-ethyl) and nitrogen on the growth and physiological characteristics ofturfgrass. The action mechanism of plant growth retardant to inhibit the growth of turfgrass is to reduce turfgrass internodes cell elongation by inhibiting biosynthesis ofGibberellic acid. The study investigated the effect of plant growth retardant in differentnitrogen levels to the height of plant, height increase of turfgrass, clipping yield, flowersheight, chlorophyll content, turf quality, clipping nitrogen content and the total removal ofN, P, K by the turfgrass clipping. The main results are summarized as follows:In spring and autumn, cool season turfgrass grows very quickly. Plant growthretardant in different nitrogen levels showed the difference in inhibiting to the height ofplant, in spring, the maximum inhibition period to the net growth inhibition rates of heightunder 9N, 6N, 3N, 0N reached 52%, 59%, 47%, 52%, while in autumn, this numberwas 67%, 68%, 59%, 78%. Plant growth retardant in different nitrogen levels also hassignificant effect on the clipping yield. In spring, the total clipping yield was significantlyreduced under the four N-level treatments of 9N, 6N, 3N and 0N. The inhibition rates were17%, 18%, 20%, 16%, while in autumn, this number was 21%, 11%, 21%, 25%. So itcan reduce turf mowing frequency, reduce mechanical wear and tear, and cut the cost ofmaintenance.Plant growth retardant in different levels of nitrogen had different effect in differentseason to turf grass quality. In spring, the plant growth retardant has increased turf qualityin the evening under three nitrogen levels of 9N, 6N and 3N. But in autumn under threenitrogen levels of 9N, 6N and 3N, Primo early treatments to reduce turf quality late toimprove turf quality. In spring Primo treatment significantly enhanced turf grasschlorophyll content only under the two nitrogen levels of 9N and 6N. Other treatmentswere not significant compare with the check. The effect to turf grass chlorophyll content ofplant growth retardant in different levels of nitrogen was positively correlated with itseffect to turf grass quality in autumn. In spring, the plant growth retardant in different levels of nitrogen nearly had noeffect to dipping nitrogen content. Primo significantly increased nitrogen content onlyunder the two nitrogen levels of 3N and 0N. More obvious influence was in the autumn,the plant growth retardant significantly increased the nitrogen content of clipping under thethree nitrogen levels of 6N, 3N and 0N.In the study, plant growth retardant was different degrees of reduction of nitrogen,phosphorus and potassium with output under different nitrogen levels which reduced thesoil nutrient loss. The effect was better in autumn than in spring. Mainly because of theautumn of turfgrass dipping inhibition rate higher.In conclusion plants retardant used less could control turfgrass growth significantly;proper use could improve turf quality, reduced frequency of mowing, reduced nutrient lossand lower maintenance costs.

The Dwarfing Effect and Ornamental Evaluation of PP333 and CCC Foliage Spraying on Ornamental Eggplant

Egg-fruit Eggplant,which is also named as gold silver fruit and ornamental eggplant, is a kind of precious ornamental vegetables germplasm resource. It grows excessively in the plant height and figure under natural conditions, so plastic operation at the regular intervals managing must be done. The tradition flowers and plants dwarfing technology, such as top removal and bending operation, mostly take a lot of time and work. The economic effect is not so good, so they are unsuitable for large-scale and industrialized production. Effects of foliage spraying of PP333 and CCC on the dwarfing effect and main ornamental characters were investigated in this experiment, whose main results are as follows:(1)Both of the plant-growth retardants could effectively control the main plant characters to a different degree. They could inhabit the plant growth, decrease the length of main stem and ramification, diminish the leaves and make the fruit round. The effect of PP333 treatment in ornamental evaluation is better than that of CCC, and PP333 at 400 mg/L produces optimal effect;(2)According to the golden section theory, the effect of PP333 treatment make the close ratio of main stem/plant height and crown/plant height to golden section, so the ornamental value of plant figure improve but the round fruit decrease the ornamental value of fruit;(3)The comprehensive evaluation using the gray system theory shows: the grey relationship degree of PP333 treatment whole is better than that of CCC, and the PP333 at 400 mg/L produces the biggest one: 0.897, which is the closest one to ideal.

Effect of Seed Soaking in Plant Growth Retardant on Germination and Physiological Characteristics

Plug in the breeding conditions due to the highly centralized of production and particularity of plug structure, the excessive growth of the plants is a very serious problem. It is a kind of simple and convenient method with instant effect to use plant growth retardants (PGRs) to control the phyiology growth of plants.As to this, this thesis selected cucumber and tomato as test materials, studied the retardant effects of different concentration of PP333 (50 mg·kg-1, 100 mg·kg-1, 500 mg·kg-1, 1000 mg·kg-1), S3307(0.1 mg·kg-1,0.2 mg·kg-1, 0.4 mg·kg-1, 0.8 mg·kg-1), CCC(2000 mg·kg-1, 4000 mg·kg-1,6000 mg·kg-1, 8000 mg·kg-1) and B9(6000 mg·kg-1, 9000 mg·kg-1, 12000 mg·kg-1,15000 mg·kg-1), and identified the best concentration and mixed proportion. After treatment the seeds ofФ12 cm dish on the Light incubator for germination test; another part of planting hole in the 128 set in a glass greenhouse. The physiology were investigated with the following results:1. test of germinationSeed germination percentage , germination rate and long of bud were controlled, root length and root vigor of seed were promoted and fresh weight of seed was reduced with treatment of cucumber and tomato seed by PP333,S3307,CCC and B9. P3,S2,C3 and B2 were optimal concentration for cucumber. P2, S2, C3 and B1 were optimal concentration for tomato.2.1 Seedlings emergence percentage and seed vigor of cucumber were controlled with treatment of seeds by PP333, S3307, CCC and B9. P3, S2, C3 and B2 were optimal concentration for cucumber. Seedlings emergence percentage was increased, but seed vigor was decreased with the treatment of tomato seeds by PP333、S3307、CCC and B9. P1, S2, C2 and B1 were optimal concentration for tomato .2.2 Sound seedling index, stem diameter and root/shoot ratio were increased with treatment of seeds by PP333, S3307, CCC and B9. P3, S2, C3 and B2 were optimal concentration for cucumber. After 40 d of sowing, sound seedling index greater than the control , respectively 28%, 7%, 7% and 3%, and root/shoot ratio greater than the control, respectively 3.62 %, 14%, 25% and 26% for cucumber. After 45d of sowing, sound seedling index greater than the control , respectively 76%, 75%, 75%, 63% with the treatment of P2, S2, C3 and B1 for tomato. And root/shoot ratio greater than the control, respectively 34%, 62%, 24% and 14% with the treatment of P1, S2, C2 and B1 for tomato.2.3 The contents of chlorophyll were increased, but the leaf area was controlled with treatment of seed by PP333, S3307, CCC and B9. P3, S2, C3 and B2 were optimal concentration for cucumber. After 40 d of sowing, contents of chlorophyll greater than the control , respectively 22%, 41%, 11% and 9% with the treatment of P3, S2, C3 and B2 for cucumber.After 45d of sowing, contents of chlorophyll greater than the control , respectively 30%, 34%, 32%, 20% with the treatment of P2, S3, C3 and B2 for cucumber.2.4 The root vigor was increased with treatment of seed by PP333, S3307, CCC and B9. After 40 d of sowing, root vigorof cucumber greater than the control , respectively 37%, 50%, 55% and 24% with the treatment of P3, S2, C3 and B2. After 45d of sowing, root vigor of tomato greater than the control , respectively 31%, 76%, 43%, 20% with the treatment of P2, S3, C3 and B2.2.5 The activity of SOD, POD and CAT were increased treatment of seed by PP333, S3307, CCC and B9, so that it reduced harm of the accumulation of reactive oxgen species to cell. P3, S2, C3 and B2 were optimal concentration for cucumber. For cucumber seedlings, the activity of SOD, POD and CAT were greater than the control with the treatment of P3, S2, C3andB2,respectively 26%, 25% and 15%;23%, 30% and 25%;15%, 27% and 20%;26%,22% and 15%. For tomato seedlings, the activity of SOD, POD and CAT greater than the control with the treatment of P2,C3 and B2,respectively 26%,21% and 16%;28%,21% and 10%;27%, 24% and 15%, the activity of SOD greater than the control with the treatment of S3 by 30%, the activity of POD and CAT greater than the control with the treatment of S2 by 25% and 15%.2.6 The contents of Pro, osmotic regulation and resistance were increased with treatment of seed by PP333, S3307, CCC and B9. The contents of Pro were greater than the control with the treatment by optimal concentration of P3, S2, C3 and B2, respectively 22%, 29%, 22% and 20%. The contents of Pro were greater than the control with the treatment by P2, S3, C3 and B1 for tomato, respectively 21%, 25%, 25% and 17%.2.7 The contents of MDA increase were alleviated with the treatment of seed by PP333, S3307, CCC and B9, so that it reduced harm of membrane system of cell. The contents of MDA were lower than the control with the treatment by optimal concentration of P3, S2, C3 and B2, respectively 15%, 22%, 28% and 13%. The contents of MDA were lower than the control with the treatment by P2, S3, C2 and B1 for tomato, respectively 10%, 12%, 8% and 13%.

Study on Improving the Quality of Astragalus Sinicus L. by Nutrient Solution and Growth Retardant

Soilless cultivation is a technology that can be applied to provide nutrient to plant not in natural soil but in the nutrient solution that contains the necessary elements for the growth of plants; with this technology, the plants can pass its whole life cycle in the normal way. In soilless cultivation, whether a reasonable proportion and moderate concentration of nutrient solution can be provided is the key which can lead to the success of the cultivation. Astragalus sinicus L., annual herb, belongs to Leguminosae of Astragalus family. Because it can cover the ground in winter when other chlorophyte disappear, and it also has the value to be appreciate, it can be utilized and developed as a chlorophyte.Ningbo da qiao–one breed of Astragalus sinicus L.was used in this experiment. According to research on concentration of nutrient solution and plant growth retardant, the concentration of nutrient solution and plant growth retardant fitting in with its growth were selected out in this thesis. The results were as follows:①Six concentrations of nutrient solution were adopted in this experiment. After analysis data about effect of every treatment of concentration on growth indexes of Astragalus sinicus L., the treatment 8s is more suitable for its growth.②Different concentration treatment of Uniconazol and Paclobutrazol optimized the population structure of Astragalus sinicus L.. The plant height got shorter and the leaf color deepened; however, the effect of inhibition was poor at lower level of concentration. 200mg/L Paclobutrazol treatment has better effect of height control, and 150mg/L is the next. The better concentration of Uniconazol to control the height is 200mg/L, the next is 100mg/L. Secondly, Uniconazol and Paclobutrazol treatment can both increase the resistance of Astragalus sinicus L. effectively. After all-round consideration of the effect of two factors on Astragalus sinicus L., the optimal concentration is 200 mg/L Paclobutrazol treatment and 100mg/L Uniconazol treatment, and effect of the former is better.③In view of comprehensive evaluation, the apparent quality of Astragalus sinicus L.was quite good after treated with 200mg/L(PP333), the next is 100mg/L (S3307).

The Effects of Plant Growth Regulators on Caragana Korshinskii Kom. Seedling Growth and Stress Resistant Physiology

This paper is the research about the growth regulators on caragana korshinskii kom.seedling growth and stress resistant physiology.The main result to show:(1)Study the effect of different seedling age of caragana to its plant height,ground diameter,biomass and root system by the field experiment.The results showed that the growth retardants could inhibit different seedling age of Caragana’s ground plant height and biomass,but could promote its ground diameter and surface area and volume of root.The same seeding age Caragana which disposed with different amount growth retardants,the length,surface area and volume of root all increased.Disposed with 40ml/point’s increased obviously. Compared the age,the smaller the seeding,the effect of the growth retardants to its the length,surface area and volume of root.(2)Study the change of the leaves’relative water content,chlorophyll content,MDA content,etc.of the seeding in drought stress. Make the overall merit by membership function.The results showed that the seeding’s drought resistance which treated with growth retardants by seed soaking increased obviously compared with control sample.The order from strong to weak of the drought resistance is 1:11>1:16>1:21>1:6>1:1>control sample.Along with the increasing of the soaking seed time,the drought resistance increased too.