Translocation of leaf-fed 32P in pea plants as influenced by foliar and root applications of CCC and Phosfon

In controlled environment growth chambers, the effects of foliar and root applications of 2-chloroethyltrimethylammonium chloride (CCC) and 2,4-dichlorobenzyltributylphosphonium chloride (Phosfon) on the translocation of³²P fed to leaves, were investigated. When applied to leaves or to root, CCC had no effect on the relative amounts of³²P radioactivity retained by the fed leaf 5, 20 and 80 h after feeding. At 20 and 80 h after feeding, Phosfon concentrations of 0.01 and 0.1mg l^?1 reduced retention of the applied³²P. 80 h after³²P feeding, CCC concentration of 1 mg l^?1 applied as a foliar spray or to the root enhanced the downward movement of³²P. Phosfon at low concentrations, particularly at 0.1 mg l^?1, on the other hand, favoured an upward transport of the applied³²P. Foliar applications of CCC and Phosfon at high concentrations had no significant effect on³²P transport to the root and the shoot below the fed leaf, while root applications of CCC and of Phosfon inhibited downward transport. Root applications generally caused greater alterations in³²P distribution patterns than did foliar applications. On the basis of total active ingredient uptake, Phosfon was more effective than CCC in altering translocation patterns.     

Uptake and translocation of root-fed32P in response to foliar and root applications of CCC and phosfon inPisum sativum

The uptake and translocation of³²P applied to nutrient solutions, as influenced by (2-chloroethyl) trimethylammonium chloride (CCC) and 2, 4-dichlorobenzyltributylphosphonium chloride (Phosfon), were investigated in growth chambers. Specific effects depended on the “Retardin”, the method of application, and the concentration. Foliar applications of CCC had no significant effect on³²P uptake 5 h after feeding. At 20 and 80h after feeding, CCC at 100 and at 1 000 mg l^?1 decreased P uptake. With root applications of CCC the same concentrations decreased P uptake as early as 5h after feeding, while the 1 mg l^?1 concentration enhanced P uptake by 40% after 20h. Both the foliar and the root applications of Phosfon influenced P uptake 5h after feeding. With foliar applications the low Phosfon concentration of 0.01 mg l^?1 increased P uptake throughout the experimental period of 80h, but the magnitudes of enhancement declined from 109% at 5h to 63% at 80h. Similarly, the enhancement of P uptake due to the 0.1 mg l^?1 foliar treatment declined from 132% at 5h to 80% at 80h. 100 mg l^?1 CCC enhanced P translocation to the shoot in 5h, with magnitudes of 29% (foliar application) and 64% (root application). At 20 and 80h the stimulations were nullified. The highest concentrations (100 mg l^?1 CCC; 10 mg l^?1 Phosfon) enhanced P translocation 80h after feeding. There were thus general enhancements of P uptake at low concentrations and suppressions at high concentrations, but these effects diminished with time, indicating transitory influences.     

Growth, Sex Expression and Yield of Squash Melon (Citrullus vulgarisvar. fistulosus) as Influenced by 2(chloroethyl)phosphonic acid, 2,3,5-tri-iodobenzoic acid and (2-chloroethyl) trimethyl-ammonium chloride

Single aqueous sprays of 2(chloroethyl)phosphonic acid (CEPA) 250, 500 and 1000 mg/1; 2,3,5-triiodobenzoic acid (TIBA) 25, 50 and 100 mg/1; and (2-chloroethyl) trimethyl-ammonium chloride (CCC) 250, 500 and 1000 mg/1 were applied to squash melon (Citrullus vulgaris Schrad. var. fistu-losus Stocks.) at the 2–3 leaf stage. Though the final length of the main axis and number of lateral branches were not affected by any treatment, CEPA retarded growth of young plants by reducing the internodal length. It did not change the flowering pattern but delayed flowering and reduced the production of both pistillate and staminate flowers. However, it increased the per cent femaleness as a result of comparatively more suppression of staminate flowers. The TIBA 25 and 50 mg/1 and CCC 500 mg/1 did not affect the staminate flower production but increased the pistillate flowers, which increased the per cent femaleness. The CEPA decreased while both TIBA 25 and 50 mg/1, and CCC 500 mg/1 increased the number of fruits per plant and the yield. The mode of action of the chemicals has been discussed.     

Growth of bean and tomato plants as affected by root absorbed growth substances and atmospheric carbon dioxide

Summary Bean and tomato plants were grown in solution culture root media containing pre-determined concentrations of gibberellin A₃ (GA), 1-naphthaleneacetic acid (NAA), N⁶-benzyladenine (BA), (2-chloroethyl)trimethylammonium chloride (CCC), and at atmospheric levels of 300 and 1000 ppm of CO₂. Net assimilation rates (NAR), relative growth rates (RGR), leaf area ratios (LAR), root to top dry weight ratios (R/T) and changes in dry weight, size, and form of each organ were recorded.Gibberellin had no effect on RGR of either plant species but increased the NAR of tomatoes at 1000 ppm CO₂. Total dry weight was only slightly affected by GA but root growth and R/T were markedly depressed. CCC had no effect on NAR, but decreased RCR and LAR. Root growth of beans and R/T in both plants were promoted by CCC. NAR and RGR were strongly inhibited by BA and NAA. Inhibition of stem and leaf growth by CCC and NAA was greater than that for roots; thus, R/T ratios were increased. Root branching was promoted by NAA.High (1000 ppm), compared to the low (300 ppm), atmospheric levels of CO₂ generally promoted root growth and produced an increase in the R/T, both in the absence and presence of chemical treatment. The multiplicity of effects of the rootabsorbed chemical growth substances and CO₂ on growth and photosynthesis is discussed.Journal article No 3883 of the Michigan Agricultural Experiment Station.NATO Fellow, University of Pisa, Italy.     

Effect of Growth Retardants on α-Amylase Production in Germinating Barley Seed

The effect of growth retarding compounds, (2-chloroethyl)trimethylammonium chloride (CCC), 2-isopropyl-4-dimethylamino-5-methylphenyl-1-piperidinecarboxylate methyl chloride (AMU-1618), tributyl-2,4-dichlorobenzylphosphonium chloride (Phosfon D) and N-dimethylamino succinamic acid (B-995) on α-amylase production in germinating barley seed was studied. Seeds were germinated in growth retardants in presence and absence of gibberellic acid (GA₃). CCC, AMO-1618 and Phosfon D inhibitedα-amylase production in germinating seed and the effect was reversed by GA₃ Phosfon D and AMO-1618 were stronger inhibitors of α-amylase production than CCC. CCC was by far the strongest inhibitor of all the other analogs tested. B-995 was comparatively only slightly inhibitory. The results reported here, when viewed in light of the results of other workers, provide good evidence that CCC, AMO-1618 and Phosfon D inhibit α-amylase production by inhibiting the synthesis of gibberellin or gibberellin-like hormone(s) during germination of barley seed. Consistent with other reports, B-995 possibly acts by other mechanism (s).     

Interaction of Growth Retardants and Temperature in Growth, Flowering, Regeneration, and Auxin Activity of Begonia × cheimantha Everett

Soil application of CCC reduced stem and leaf growth in Begonia plants. This effect was evident with all concentrations tested at 18°C, whereas at 21 and 24°C no growth–retarding effect was observed with 2 × 10^?2 M CCC, and with 5 × 10^?3 M growth was even stimulated. Flowering was promoted by CCC in long day and neur–critical temperature, particularly under low light intensity in the winter. The formation of adventitious buds in leaves of plants grown at 21 and 24°C was stimulated when the plants received 5 × 10^?2 and 2 × 10^?2 M CCC, while 8 7times; 10^?2 M was inhibitory. In plants grown at 18°C bud formation was inhibited by all CCC concentrations. Root formation in the the leaves was usually stimulated by high CCC concentrations, while root elongation was reduced. The level of ether–extractable. acidic auxin (presumably IAA) in the leaves was lowered by CCC treatment of the plants, hut this required higher CCC concentrations at higt than at low temperature. When applied to detached leaves CCC stimulated bud formation at concentrations ranging from 10^?4 to 10^?2 M in leaves planted at 18 and 21°C. At 24°C budding was inhibited by 10^?2 M CCC, the lower concentrations being stimulatory also at this temperature. Root formation and growth were not much affected by CCC treatment of the leaves, but increased with the temperature. Soil application of Phosfon (4 × 10^?4 M) had no effect on growth and flowering, nov did it affect the subsequent regeneration of buds and roots in the leaves. In detached leaves Phosfon stimulated bud formation with au optimum at 10^?6 M. Root formation was stimulated by Phosfon at all temperatures, the optimal concentration being 10^?5 M, whereas root length was conversely affected. Foliar application of B-995 to intact plants and treatment of detached leaves greatly inhibited the formation of buds and had little effect on root formation. B-99D reduced the growth and delayed flowering in the plants.     

Contribution of the wheat (Triticum aestivum L.) flag leaf to grain yield in response to plant growth regulators

In West-Europe, intensive cereal management uses plant growth regulators (PGRs) especially for wheat. A green-house experiment compared the effects of two PGRs on flag leaf characteristics and yield of winter wheat. Chlormequat chloride + choline chloride (CCC) and chlormequat chloride + choline chloride + imazaquin (CCC+I) were applied to winter wheat at growth stage 5 (Feekes Large scale). CCC and CCC+I significantly increased flag leaf surface area at anthesis. Both treatments also enhanced chlorophyll content of the main stem flag leaf. The grain filling period was extended with PGR application by 2 days. CCC and CCC+I significantly increased net CO₂ assimilation rates during the flag leaf life. No effects of PGR spraying were observed on the pattern of ¹⁴C labelled assimilate distribution. Increased grain yield was due to the increase in average grain weight. The results indicate that PGR treatments increased flag leaf contribution to grain filling. The addition of imazaquin (I) to chlormequat (CCC) improved the effects of CCC.     

The Influence of Moisture Stress on Liriodendron tulipifera L. Seedlings

A comparison of yellow poplar seedlings subjected to availablemoisture ranging from 100 per cent to 20 per cent of field capacityin two separate experiments (a soil study and a solution study)indicated that total dry matter production, stem height, totalleaf area and area of individual leaves, decreased with increasedmoisture stress. Differences in unit leaf rate (ULR) were primarilyresponsible for final plant size. Leaf area: weight ratio wasaffected by the method of induced stress. As stress increasedthe ratio increased in the soil study but decreased in the solutionstudy. The number of leaves produced was unaffected by stress,except at the most severe stresses. The number of senescentleaves increased as moisture stress increased. The allocationof new growth was unaffected by either moisture stress or timeand decreased in order of root, foliage, stem for the soil grownplants and foliage, root, stem for the solution grown plants.ULR and relative growth rate (RGR) were reduced by both moisturestress and time. A growth simulation of the soil-grown plantsbased on results from the solution moisture stress experimentpredicted the final plant dry weight within 12 per cent andleaf area within 7 per cent of the actual values.     

Suppression of floral induction inBryophyllum daigremontianum by a growth retardant

Summary Flower formation in the long-short-day plantBryophyllum daigremontianum induced by the shift from long to short day is fully suppressed by applying the growth retardant CCC [(2-chloroethyl)-trimethylammonium chloride]via the roots during short day treatment at a level of at least 1 g per plant. At the same time CCC applications strongly reduce the internode length, but the rate of leaf formation does not seem to be affected. CCC also causes the production of more anthocyanin in the leaves.Gibberellin A₃ appliedvia the apices and youngest leaves at a dose of 1.5 g per plant, completely overcomes the inhibition of flower formation caused by CCC. Ten times higher quantities are needed for a complete reversal of the reduction in stem elongation.The growth retardant CCC seems to keep the level of physiologically active GA below that which is normally required for floral initiation and stem elongation. Thus, the results are in agreement with the hypothesis that a high GA level is necessary for the production of floral stimulus inBryophyllum daigremontianum.With 2 Figures in the TextThis work was supported by the National Science Foundation, grants G-16408 and G-17483.     

Response of Cowpeas to Salinity and (2-Chloroethyl) trimethyl-ammonium Chloride (CCC)

Recent investigations have demonstrated that the growth retardant, (2-chloroethyl) trimethyl-ammonium chloride (CCC) inhibits several aspects of vegetative growth. In solution culture experiments, reduction in plant growth and dry matter production was confirmed in cowpeas, Vigna unguiculata L, (cv. Makueni II), when treated with CCC. The growth retardant had negligible effect on the rate of transpiration per unit leaf area although it slightly increased the relative water content of leaves. Stomatal opening was suppressed by CCC treatment but the number of stomata per unit leaf area was increased by the growth retardant. Variations in mineral element content (K, Ca, N and Na) of shoots are presented and discussed in relation to CCC treatment.     

CCC-Induced increase of gibberellin levels in pea seedlings

Summary Pea seedlings (cv. Alaska), were treated with two concentrations of (2-chloroethyl)trimethylammonium chloride (CCC) and choline chloride. Treatment with 1 mg/l CCC resulted in as much as a 150fold increase in endogenous gibberellin (GA) levels without there being any parallel stimulation of growth. Plants grown in 1,000 mg/l CCC were severely dwarfed but contained GA levels not significantly different from control plants grown in distilled water. CCC also retarded GA₃-induced growth of pea seedlings. These effects appear to be CCC specific as the CCC analogue choline chloride affected neither the GA content of pea seedlings nor their response to GA₃. The lack of correlation between endogenous GA levels and stem height suggests that in peas the predominant factor in CCC-induced inhibition of stem growth is not related to an effect of CCC on GA biosynthesis.Supported by National Research Council (Canada) grant A-5727.Supported by a Postdoctoral Fellowship from NRC Grant A-2585 to R.P. Pharis.     

On the interaction of growth retardants with IAA and kinetin

In the pea test a highly positive response to the treatment with IAA reversed to a negative one or became 5 to 6 times weaker when CCC was applied together with IAA. In cultivating pea seedlings, following their decapitation, for two days in a 0.25 per cent CCC solution and then in water, growth of their cotyledonous axillaries (cotylaries) were inhibited. This inhibitive action of CCC could be made ineffective when the seedlings, following two-days’ cultivation in the CCC solution, were grown further in kinetin solutions (0.37–3 mg per 1). Cotylaries of decapitated pea seedlings, when grown in kinetin solutions were inhibited. With kinetin solutions of 6–12 mg/l a strong inhibition also occured in the growth of roots at the apical parts of which spherical swellings were developing. The CCC supplied to the roots of intact etiolated pea seedlings is translocated acropetally into the stem at a rate of about 5 cm per hour. Decapitation of the plant causes retardation of this transport, yet a coat of 0.00001–1% IAA or kinetin paste produces acceleration of the stream. Existence of an antagonism between CCC and IAA, demonstrated earlier, was found holding true also for B-9 (N, N-dimethyl-aminesuccinamic acid) and IAA, as the inhibitive action of B-9, 0.06% solution on the growth of lettuce hypocotyls was reduced to a highly significant degree when the plants were supplied with B-9 together with IAA at a concentration of 10 mg/l.     

The Stability of the Growth Pattern of Young Apple-trees under Four Levels of Illumination: With four Figures in the Text

As part of a programme on the characterization of the growthpattern of the apple-tree, uniform I-year-old plants carryingtwo new shoots were grown for a season under 100, 78, 41, or24 per cent, natural light. Weights of leaf, new stem, old stem,and root were determined by sampling on 6 occasions. The dryweightincrements over the whole season ranged from 17 to 151 g. ofwhich, in full light, 22 per cent, was leaf and 22 per cent,was root; in deep shade, 32 percent, was leaf and 8 per cent,was root; and under all conditions 56–60 per cent, wasstem. These percentages were the cumulative result of currentrates of growth of leaf, stem, and root over the whole growingperiod. The rates were not constant relative to one another,but the much greater quantity of growth made over the period100–200 days from bud-break swamped earlier differences.All treatments showed the same basic pattern of growth withminor differences increasing with the intensity of shading.These differences are discussed in relation to utilization ofreserves and the demands of the various regions of the plant.The response to shading was analysed into the effects of reducedlight interception, increased leaf dispersion, increased leafproportion, reduced length of growing season, and lighter leafweight at the beginning of the 20-leaf stage. The result ofthese factors was a doubling of the growth expected in the absenceof response. It was concluded that the pattern of growth isstable, and the conditions for the perpetuation of such stablepatterns as a necessary qualification for tree growth are brieflydiscussed.     

EVIDENCE ON THE SITE OF ACTION OF GROWTH RETARDANTS

1. The ability of five growth retardants to inhibit the GA-inducedand endogenous growth of Avena leaf sections has been investigated.The retardants vary in effectiveness. The order, from most effectiveto least, is Phosfon D, Amo-1618, C011, CCC and B995. 2. The inhibition of growth caused by Phosfon D and Amo-1618is not reversed by GA. It is apparent that the retardants donot compete with GA at the site of GA-action. 3. Addition of IAA will partially reverse the inhibition inducedby Phosfon D or Amo-1618. It is concluded that the retardantsact in part in Avena leaf sections by interfering with the auxinmetabolism of the tisssue. ¹ Supported in part by grants G-14578 and GB-1950 from the NationalScience Foundation ² Present address: Department of Botany, University of Washington,Seattle, Washington     

Effects of Chlorocholine Chloride and Water Regime on Growth, Yield, and Water Use of Spring Wheat

When CCC was applied as a spray to the leaves of Brassica oleraceaL. (Brussels sprout) grown in pots, plant height and mean internodelength were reduced. The effects appeared more slowly and wereless pronounced than those previously observed when CCC hadbeen applied to the soil; other differences were that root growthwas not inhibited, stem weight was only significantly reducedat the highest rate of application (2 per cent), and stomatalnumber per unit area of lower leaf epidermis was not affected.In common with soil applications, leaf thickness, stem diameter,and the percentage moisture contents of the leaves were allincreased by foliar applications.In a further experiment theprogress of wilting was observed in untreated plants and inplants treated with CCC applied either to the leaves or to thesoil. The rates of water loss and the moisture contents of theleaf laminae of the treated plants, after a period of wilting,were not significantly different from the controls. The treatedplants, however, looked less ‘wilted‘ for the changein angle of the leaf lamina to the stem was less and their leaveswere therefore held more upright.     

Effects of 2-Chloroethyl Trimethylammonium Chloride (CCC) and 2-Chloroethylphosphonic Acid (CEPA) on Dry Matter Distribution in the Cowpea (Vigna Unguiculata L.)

Effects of foliar applications of CCC and CEPA on dry matterdistribution in two cowpea cultivars which exhibit differentdegrees of premature abscission of fruits were investigated.At the concentration of 0-1 mg1^–1, CCC increased stemweight in the cultivar Adzuki, but had no effect on the cv.Mala (which exhibits a relatively high degree of premature abscission).While CCC did not significantly influence root weight in Adzuki,the concentrations of 1 and 10 mg 1^–1 increased root weightin Mala. In both cultivars, the 1000 mg1^–1 treatment decreasedseed weight, with a greater decrease in Adzuki. All concentrations of CEPA, up to 1000 mg 1^–1, decreasedstem and root weights in Mala, and leaf weight in Adzuki. The10 mg1^–1 concentration increased seed weight in Mala by100 percent, and leaf weight by 28 percent, without any significanteffect on pod weight, or on the weight of the whole plant. Therewas also no increase in pod number. Overall, Mala was more responsive than Adzuki to the growthregulators, particularly CEPA. In the low concentration responses,CEPA increased seed weight not by increasing gross plant weight,but mainly by causing a change in distribution of dry matter.     

Response of Java citronella (Cymbopogon winterianus Jowitt) to toxic heavy metal cadmium.

Cadmium at 200 mg kg-1 soil and above concentrations was fatal as growth was inhibited ultimately leading to death of Java citronella (Cymbopogon winterianus Jowitt.). The surviving plants at 50 and 100 mg kg-1 treatments also exhibited pronounced retardation of growth and biomass yield. There was considerable reduction in the level of essential oil in herbage and oil quality deteriorated. Cadmium accumulation profile showed that highest accumulation was in root, followed by stem, leaf sheath and leaf. Very high accumulation in root for higher doses appeared to be the reason for fatality.     

Effects of gibberellic acid and chlormequat chloride on the proportion of phloem and xylem parenchyma in the storage root of carrot (Daucus carota L.)

A foliar application of gibberellic acid (GA) (100 mg/l) 5 weeks after emergence increased the shoot/storage root ratios, measured 4 weeks later, of 9 cultivars representing a range of types of carrot. Chlormequat chloride (CCC) (2000 mg/l) decreased the ratio for seven of the cultivars. Assessment 8 weeks after treatment showed fewer significant effects of both growth regulators.At the first harvest, GA decreased the phloem/xylem ratio and significantly reduced the amount of secondary phloem produced in the storage root of all cultivars. CCC had no comparable effect except for an increase in the phloem/xylem ratio for one cultivar at both harvests. The significance of these results is discussed in relation to secondary vascular tissue production in storage roots as affected by assimilate partitioning in the whole plant.     

四种亚高山针叶林树种的表型可塑性对不同光照强度的响应

以青藏高原东缘亚高山针叶林群落演替后期种岷江冷杉、演替中后期种粗枝云杉和青榨槭、及先锋树种红桦为材料,研究了不同光强下生长的4种树苗生长、生物量分配、叶片形态和光合特性,探讨植物幼苗的形态和生理特征的表型可塑性与光适应的关系。结果表明：（1）弱光环境中生长的4种植物的基茎、相对生长速率、叶片厚度、根重比、最大净光合速率、光饱和点、光补偿点、暗呼吸速率较低,而比叶面积、地上／地下生物量、茎长／茎重、叶重比和茎重比较高。（2）大部分光环境下岷江冷杉幼苗的最大净光合速率和暗呼吸速率低于粗枝云杉,青榨槭幼苗的最大净光合速率和暗呼吸速率略低于红桦。（3）高光强下生长的粗枝云杉和红桦幼苗的相对生长速率分别大于岷江冷杉和青榨槭,但在低光强下则与之相反。（4）粗枝云杉和红桦幼苗的11种可塑性指数平均值则分别大于岷江冷杉和青榨槭。岷江冷杉适应弱光环境的能力略强于粗枝云杉和红桦,但适应强光的能力较差。生理适应的可塑性指数大于形态适应的可塑性指数,表明前者在4种植物幼苗光适应方面起到了重要的作用。研究结果支持树种的生理生态特性决定了其演替状况和生境选择的假说。     

COMPARATIVE CYTOHISTOLOGICAL STUDIES ON INHIBITION AND PROMOTION OF STEM GROWTH IN CHRYSANTHEMUM MORIFOLIUM

Sachs , R. M. (U. California, Davis), and A. M. Kopranek . Comparative cytohistological studies on inhibition and promotion of stem growth in Chrysanthemum morifolium. Amer. Jour. Bot. 50(8): 772-779. Illus. 1963.—The present study with Amo, CCC, and Phosfon,³ 3 substances which inhibit stem elongation, shows that all inhibit subapical cell expansion and division in Chrysanthemum morifolium var. ‘Indianapolis Yellow.‘ Furthermore, GA,³ in preventing the inhibition of stem elongation, maintains subapical activity at normal or greater than normal levels. For comparative purposes concentrations of the retardants and GA have been selected which completely prevent or promote the maximum rate of stem elongation. Phosfon causes complete inhibition of root growth and almost completely prevents dry matter accumulation in the tops. However, GA does not prevent such deleterious effects. Thus, GA and the growth retardants are mutually antagonistic only with respect to stem elongation and not to other aspects of growth. Furthermore, none of the retardants inhibits transverse stem growth; on the contrary transverse cell expansion and division in the subapical tissues are stimulated by the retardants, and as a result the stems of such plants are thicker than normal. GA not only prevents the thickening effect of the retardants, but, at the doses applied, GA-treated stems are considerably thinner than those of the controls, having fewer and smaller cells across the pith, cortical, and vascular tissues. Apparently, then, there is a relationship between longitudinal and transverse growth in the subapical tissues such that if one is promoted, the other is inhibited.