Weight Of Buds Research Articles

Photoautotrophic Micropropagation of Triploid Melon. I: Sucrose, Light, and CO2 Affect Growth and Net Photosynthetic Rates of Shoot Buds

Growth and net photosynthetic rates of shoots of a triploid melon clone, `(L-14 × B) × L-14', were observed over 21 days following transfer from a multiplication MS medium containing 3% sucrose and 10 μM BA to a shoot development medium containing 1 μM BA at varying levels of sucrose in the medium (0%, 1%, and 3%), and light (50, 100, and 150 PPF) and CO2 (500, 1000, and 1500 ppm) in the headspace. Largest numbers of shoot buds were observed in media with 3% sucrose. Increased light and CO2 had a positive interactive effect. Fresh and dry weights were greatest at highest levels of sucrose, light, and CO2. Although there was less growth in the absence of sucrose, fresh or dry weight of shoot buds grown without sucrose in the media still doubled over the 21 days of culture. Net photosynthetic rates of buds were negative 4 days after initiation of culture and approximately zero after 20 days of treatment. When transferring buds to fresh, sugar-free media, net photosynthetic rates became highly positive. Buds that had been cultured in the absence of sucrose and at highest light levels had the highest net photosynthesis rates upon transfer to fresh, sugar-free media.

Salinity Effects on Bud Yield and Vegetative Growth of Artichoke (Cynara scolymus L.)

Globe artichokes recently have been planted in the irrigated desert area of southern California. Soils in this area are, or have the potential to become, highly saline from the application of saline irrigation water. Thus, a 2-year field plot study was conducted. A control and five saline treatments were imposed by irrigation with waters that contained equal weights of NaCl and CaCl. Bud yield and vegetative growth were measured. For the two years, relative bud yield was unaffected up to a soil salinity of 6.1 dS·m [electrical conductivity of the saturated soil extract (EC,)]. Each unit increase in salinity above 6.1 dS·m reduced yield by 11.5%. These results place artichoke in the moderately salt-tolerant category. Yield reduction was attributed primarily to reduced bud weight rather than bud count. Vegetative growth was more tolerant to salt stress than was bud production. Chloride concentration in midrib and blade tissue increased as salinity increased.

Effects of grafting on transpiration, CO2fixation and growth of rose plants (Rosaxhybridcvs Ilseta and Mercedes)

SummaryReduced stomatal conductance and lower rates of transpiration were measured in one year old grafted plants of rose (Rosa × hybrid) cvs Mercedes and Ilseta as compared with non-grafted plants of the two cultivars. In spite of the decreased rate of transpiration, the rate of CO2 fixation and the content of minerals in the leaves were not altered by the different scion/root combinations. The fresh weight of the flower buds in both cultivars was affected by the type of the understock used. The mean flower stem length and the average number of flowers per stem in one flowering cycle were only little affected by the understock. Selection of various rose cultivars for use as understocks is proposed.

Endogenous IAA levels and development of coffee flower buds from dormancy to anthesis

Dormant coffee (Coffea arabica L.) flower buds require water stress to stimulate regrowth. A xylem specific water-soluble dye, azosulfamide, was used to quantify water uptake of buds after their release from dormancy by water stress. In non-stressed flower buds, the rate of water uptake was generally slower and variable compared to stressed flower buds, where the rate of uptake tripled from 1 to 3 days after rewatering and preceded the doubling of fresh and dry weight of buds. Free, ester and amide IAA levels of developing flower buds were measured by gas chromatography-mass spectrometry-selective ion monitoring using an isotope dilution technique with [13C6]IAA as an internal standard. Throughout development, the majority of IAA was present as amide IAA. The proportions of amide and free IAA increased one day after plants were released from water stress, and preceded the doubling of fresh and dry weight. Free and conjugated IAA content per bud remained stable during the period of rapid flower growth until one day before anthesis.

Gene expression and carbohydrate content during stolon to tuber transition in potatoes (Solanum tuberosum)

In using an efficient and synchronised in vitro tuberisation system the transition of axillary buds from stolons to tubers in Solanum tuberosum L. cv. Bintje was followed. After 5 or 6 days on tuber‐inducing medium all axillary buds had formed tubers which increased in size until the experiment was ended at day 10. Concomitantly with the visible appearance of tubers the fresh weight of the axillary buds increased as well as their starch content. Soluble sugar content, notably glucose, increased until tuberisation occurred and dropped after that. In the daily sampled explants gene expression was studied at several levels. RNA was isolated from the different explants during the whole tuberisation experiment and northern blots were probed with cDNAs encoding genes involved in starch‐ and patatin‐biosynthesis. It was shown that in the very early stages of development hardly any transcript could be detected. Only one day before visible swelling occurred were clear signals obtained for all the genes investigated. Although it was evident that coordinate expression of starch biosynthetic genes did occur, it was not in a similar fashion for all the genes. Sucrose synthase and ADPG‐pyrophosphorylase B were expressed in an identical fashion which was different from ADPG‐pyrophosphorylase S, granule‐bound starch synthase and branching enzyme. The RNA levels of these three latter genes reached a maximum at day 5, remaining constant until the experiment was finished. The transcript levels of sucrose synthase and ADPG‐pyrophosphorylase B reached their highest level at day 5 after which they dropped to a lower level at day 10. Patatin gene expression was clearly different from that of the starch biosynthetic genes: it steadily increased from day 4 until the end of the experiment. Enzyme activities of sucrose synthase. ADPG‐pyrophosphorylase and branching enzyme confirmed the RNA expression data and showed that ADPG‐pyrophosphorylase enzyme activity reached a maximum at day 4 after which it dropped. The other two enzyme activities could be detected at or one day after tuberisation occurred and increased until the experiment was ended.

GROWING GLOBE ARTICHOKES AS AN ANNUAL IN VIRGINIA

The globe artichoke (Cynara scolymus L.) is a herbaceous, perennial dicot grown for its immature flower bud. Globe artichokes are usually propagated vegetatively from root divisions or offshoots, because plants grown from seed lack uniformity. Furthermore, only a small percentage of plants grown from seed flower during the first season without vernalization. The globe artichoke is not winter hardy and cannot be grown in areas where temperatures are <-10°C without protection. The cultivar Imperial Star was developed in California to produce uniform plants from seed and a high percentage of buds the first year. In this study, Imperial Star (IS) and Green Globe (GG) were evaluated for their ability to produce a crop during the first season from seed without vernalization in Virginia. Eight-week-old transplants were set in the field on 14 May 1991. The harvest period began on 12 August for both cultivars and ended on 28 September and 8 November for GG and IS, respectively. Eighty-one percent of the IS produced buds compared to 25% for GG. The average bud yield per plant was 12 for IS and 9 for GG. Ten and 9% of the buds were rated as off-type for IS and GG, respectively. The average bud weight was 77 and 80 grams for IS and GG, respectively. Only 54 and 49% of the IS and GG buds, respectively, exceeded the marketable weight of 75 grams. The percent marketable yield for IS was 46% and 42% for GG. The estimated marketable yield per hectare was 54,600 and 4,800 buds for IS and GG, respectively. Imperial Star is a significant improvement over GG plants grown from seed in short season areas.

THE RELATIONSHIP BETWEEN SWEET CHERRY FLOWER BUD DEVELOPMENT AND FRUIT QUALITY

The development of sweet cherry (Prunus avium L., `Bing') flower buds from winter through anthesis was examined. Shoots were collected from the top and bottom of the canopy. The weight and size of flower buds and primordia produced on last-season's and 1-year-old wood were measured. As early as mid-December bud and primordia size and weight were greater on last-season's wood than on 1-year-old wood, with the largest and heaviest buds and primordia produced on last-season's wood in the bottom of the canopy. There was a significant negative correlation between the number of primordia per bud and primordium weight. The relationship between flower bud and primordia size during mid-December and ovary size at anthesis suggests a causal relationship, which may be a major source of variation influencing harvested fruit size and quality.

Photoperiod, gibberellic acid, and kinetin, in potato flower differentiationin vitro

To inducein vitro floral differentiation on potato plantlets, one cm long apical explants cv. Marijke were excised and aseptically cultured in a semi-solid medium containing Murashige-Skoog salts supplemented with 0.3 mg/l indoleacetic acid; with or without one mg/l gibberellic acid (GA); 0.3, 3.0 or 30.0 mg/l Kinetin (K); 20, 40 or 60 g/l sucrose (S) and 8% agar, pH 5.7. After a five week growing period at 26–28 C with daily light PAR 35 μE/m2/sec, 14 or 24 h daylength (DL), flower buds developed with exposed sepals and an abscission zone in the peduncle. Statistical significance was found when the variation factors (GA, K, S, and DL) were analyzed individually or in combination for number and weight of floral buds. Absence of GA favored the number of buds/plant, and the interaction of continuous light with a culture medium containing 0.3 or 3.0 mg/l kinetin and 40 g/l sucrose induced the highestin vitro “yields” in number and weight of flower buds (6 per plant and up to 14 mg/bud), followed by premature abscission. In a similar experiment, to prevent such abscission, plants from five week old tissue culture were transferred to soil and maintained at 24 h DL and 26–28 C, but flower bud abortion could not be avoided. These results demonstrate the importance of manipulating exogenous factors (growth regulators, sucrose, photoperiod) to inducein vitro specific organogenesis in potatoes.

ENDOGENOUS IAA AND WATER UPTAKE IN DEVELOPING COFFEE FLOWER BUDS

Dormant coffee (Coffea arabica L.) flower buds require water stress to stimulate regrowth. A xylem specific watersoluble dye, azosulfamide, was used to quantify the uptake of water by buds after their release from dormancy by withholding water. In non-stressed flower buds, the rate of water uptake was generally slower and variable. In stressed flower buds, the rate of uptake tripled from one day to 3 days after rewatering and preceded the doubling of fresh and dry weight of buds. Free, ester, and amide IAA levels of developing flower buds were measured by GCMS-SIM using an isotope dilution technique with [13C6] IAA as an internal standard. Throughout development, the majority of IAA was present in a conjugated form and the dominant form was amide IAA. The proportions of amide and free IAA changed rapidly after plants were water stressed until day 3, and preceded the doubling of fresh and dry weight. Correlation coefficients of 0.9, 0.7, and 0.7 (p<0.l) were found between auxin content and fresh weight, dry weight, and rate of water uptake, respectively.

The effect of soil nutrient status on prey utilization in four carnivorous plants.

The hypothesis that carnivorous plants are less responsive to prey at high soil nutrient levels than at lower levels (Givnish et al. 1984) is tested on four plant species (Drosera rotundifolia, Pinguicula alpina, P. villosa and P. vulgaris) from a subarctic environment. The response, measured in terms of seven characteristics (winter bud weight, winter bud nitrogen and phosphorus content, flowering frequency, total seed weight, seed number and weight per seed), was analysed. Although all species responded to prey supply the response varied depending on the characteristic and species concerned. In 5 cases (out of 28 tests) the hypothesis was supported, whereas in 1 case it was refuted, i.e. the response to prey was higher for plants supplied with soil nutrients. In the remaining three-quarters of the tests, responses to prey were not significantly different between the two nutrient levels. Thus, the hypothesis that the response to prey diminishes as soil nutrient availability increases was not supported by our findings. A modification of the model presented by Givnish et al. (1984) is therefore suggested. This modified model measures the cost of carnivory as loss in growth rate and assumes that responses to prey remain unchanged as the soil nutrient content increases. Although the distribution of carnivorous plants is still predicted to be limited mainly to wet and sunny but nutrient-poor sites, the modified model also allows for their occurrence in richer habitats, provided competition is low.

Changes after Decapitation in Concentrations of Indole-3-Acetic Acid and Abscisic Acid in the Larger Axillary Bud of Phaseolus vulgaris L. cv Tender Green

Early changes in the concentrations of indole-3-acetic acid (IAA) and abscisic acid (ABA) were investigated in the larger axillary bud of 2-week-old Phaseolus vulgaris L. cv Tender Green seedlings after removal of the dominant apical bud. Concentrations of these two hormones were measured at 4, 6, 8, 12 and 24 hours following decapitation of the apical bud and its subtending shoot. Quantitations were accomplished using either gas chromatography-mass spectrometry-selected ion monitoring (GS-MS-SIM) with [(13)C(6)]-IAA or [(2)H(6)]-ABA as quantitative internal standards, or by an indirect enzyme-linked immunosorbent assay, validated by GC-MS-SIM. Within 4 hours after decapitation the IAA concentration in the axillary bud had increased fivefold, remaining relatively constant thereafter. The concentration of ABA in axillary buds of decapitated plants was 30 to 70% lower than for buds of intact plants from 4 to 24 hours following decapitation. Fresh weight of buds on decapitated plants had increased by 8 hours after decapitation and this increase was even more prominent by 24 hours. Anatomical assessment of the larger axillary buds at 0, 8, and 24 hours following decapitation showed that most of the growth was due to cell expansion, especially in the intermodal region. Thus, IAA concentration in the axillary bud increases appreciably within a very few hours of decapitation. Coincidental with the rise in IAA concentration is a modest, but significant reduction in ABA concentration in these axillary buds after decapitation.

RESPONSE SURFACE REPRESENTATION OF ROSE (ROSA HYBRIDA L.) GROWTH CHARACTERISTICS

Day (DT) and night temperature (NT), and irradiation (photosynthetic photon flux-PPF) treatment combinations were run from a rotatable central composite design. At flowering, response surfaces were plotted for `Royalty' rose for plant growth characteristics: node number, stem diameter, stem length, and dry weight of stem, leaves, flower bud, and total shoot. Overall development was recorded from pinch until visible bud, first bud color, and flowering. All characteristics except node number and stem length were significant (P=0.05) for a full quadratic model having ten estimated coefficients. Greatest dry weights were predicted at flowering for the lowest DT (15C) and NT (12C) combination, and required the longest time for development. Conversely, most rapid development and least dry weight accumulated for high DT (25C) and NT (22C). Thus, a compromise exists between rapid development and quality of the flowering stem. As PPF increased from 50 to 300 μmol m-2s-1, predictions for dry weights increased while developmental time decreased.

Changes in gene expression of Scots pine buds during the winter and under experimentally altered light and temperature conditions

Vegetative buds of Scots pine (Pinus sylvestris L.) were collected during the apparently dormant phase in January and February and at the beginning of the growth phase in May. Wintering Scots pine plants were placed in climate chambers in which either the daily photoperiod or the temperature simulated the situation in early spring, whereas the other conditions were characteristic of midwinter.The amount of total ribosome populations and their in vitro translation capacities were independent of the height of the tree or place of collection, but both were dependent on the season; the amount of ribosomes per fresh weight of buds was lower in spring than in winter, whereas the translation capacity in spring exceeded that in winter. Poly(A)+ RNA was purified from the ribosomes and translated in vitro and the translation products were separated by sodium dodecyl sulphate polyacrylamide gel electrophoresis. The polypeptide patterns proved that changes in gene expression can occur in plants growing outdoors even during the season of severe cold. In the climate chamber experiments, lengthening of the daily photoperiod increased the in vitro translation capacity of the buds within 7 days even at temperatures below 0°C, whereas a rise in temperature seemed to cause a more transient stress effect. Both treatments induced alterations in the pattern of in vitro polypeptide synthesis. It is suggested that while improvements in both light and temperature hastened the development of the buds under experimental growth conditions, the lengthening of the day may be the factor which induces a change in wintertime metabolism under natural conditions.

Influence of planting depth on Potamogeton gramineus L.

The weight of Potamogeton gramineus L. winter buds was greatest between 6 and 10 cm deep in the sediment for samples collected from two northern California irrigation canals. The relationship between winter bud weight and depth was adequately described by a polynomial equation containing a quadratic term, but coefficients in equations were different for two canals. For buds planted at various depths, after 10 weeks growth measurements in terms of plant dry weight, shoot length, rhizome length, number of flowers, ramets, leaves, and floating leaves per plant were all negatively related to planting depth. Plants growing from greater depths had lower rates of shoot elongation, leaf production, and ramet production. Allocation of biomass to photosynthetic tissues and flowers was also influenced by initial planting depth, as was the time of emergence from the sediment. These findings suggest that predicting macrophyte growth and phenology from environmental changes alone may not be adequate.

Evaluation of an Alfalfa growth simulation model under Québec conditions

A simulation model of alfalfa growth, ALF2LP derived from ALSIM 1 (LEVEL 2), was evaluated in the region of Québec, Canada. This evaluation involved three major steps: sensitivity analyses, calibration, and then validation of the model. A number of parameters; namely, the maximum relative growth rates, the specific leaf area, and the number of growing degree-days at flowering, were modified to evaluate the sensitivity of output values of leaf and stem dry matter yields. The more sensitive parameters were modified to calibrate the model with the field observations obtained in the summer of 1984 on leaf, stem, and total dry matter yield. The best fit was obtained by adjusting the specific leaf area, the maximum relative leaf growth rate, and the initial dry weight of basal buds. Equations to predict crude protein fraction and crude fiber fraction were also modified according to results obtained in 1984. The calibrated model was validated with observations on Alfa and Vernal alfalfa cultivars for years 1972 to 1974. The validation revealed that ALF2LP accurately simulates the total dry matter yield and the crude fiber percentage; predictions of the crude protein percentage were less precise.

Effect of a foliar application of paclobutrazol in autumn on the reproductive development of ‘Songold’ plum

A foliar application of paclobutrazol (1- (4-chlorophenyl) −4,4-dimethyl-2- (1,2,4- triazol-1-yl) pentan-3-ol) at 250 or 500 mg dm−3 a.i. in autumn, or late winter applications of dinitro-o-cresol oil emulsion (DNOC) in water at 3% v/v, increased the percentage of ‘Songold’ plum flower buds that opened early. Paclobutrazol applications significantly increased the dry weight of buds and flowers and the dimensions of floral parts. Applications of paclobutrazol in autumn increased the dry matter allocation in favour of reproductive bud development before the commencement of shoot growth.

Effect of type and weight of nursery produced planting material on the development of banana cv. Williams in North Queensland

Bananas cv. Williams grown from planting material produced in a nursery were studied to determine minimum planting weights for planting material from this source. There were 3 weights of both suckers (0.25-0.5, 0.5-1.0, and 1.0-1.5 kg) and bits (0.45-0.6, 0.6-1.0, and 1.0-1.5 kg). Shoot emergence from suckers occurred on average 17 days earlier than from bits. Small and medium bits had shooting failures of 8 and 2% respectively. Medium and large suckers produced 2 bearing plants in the plant crop, the 'first' from the apex, the 'second' (shoot emergence 8 weeks later) from a lateral bud. The 'second' reduced sucker growth and bunch size of the 'first'. High sucker number was more consistent on plants from small suckers, and medium and large bits in the plant crop, which facilitated selection of even-sized followers. Cropping was most uniform in these treatments in ratoons 1 and 2. Yield of medium and large suckers in the plant crop was twice that of the other treatments and represented the combined yields of the 'first' and 'second' plant. However, the average annual yield of medium and large suckers over both the plant and ratoon 1 crops (57 t/ha) was the same as the other treatments, due to both a 12% reduction in yield and a longer period to harvest in ratoon 1. Yield of small suckers, and small, medium and large bits was the same in the plant crop (25 t/ha) and ratoon 1 crop (73 t/ha). Further work is required with nursery material to elucidate its response to time of planting, and the interaction of bud state and weight of bits.

Environment and Mineral Nutrients of Beech (Fagus sylvatica L.) in South Sweden

Summary The mineral nutrients and nitrogen in beech (Fagus sylvatica L.), as estimated by the concentrations in buds and leaves from 87 sites in south Sweden are related to soil characteristics and to the geographical position with respect to the main pollution source area of the region, the communities surrounding the Sound (population ca. 2.0 mill.). Concentrations of K, P, and N in buds and leaves were usually lower and the mean bud weight higher in the western half of the study area, situated closest to the Sound region. Soil factors alone were less powerful in accounting for the variability of biomass element concentrations than in herbaceous and grarnineous plants previously studied. Considerable vertical differences within the rhizosphere of deep-rooted plants limit the possibility of defining soilplant relationships to elements with considerable differences between sites in soil exchangeable pools, e.g., Mn and Ca. It is concluded that biomass concentrations of chiefly K, P, and Mg are often close to or sometimes even below the level of sufficiency.

Correlation and Path Analysis in Jasmine

AbstractCorrelations among 11 morpho‐economic characters and their path analysis were studied using 16 genotype of jasmine. The weight of 100 flowers was significantly associated with the Dower diameter, petal width, petal length, anther length, floral bud length and width, and 100 bud weight in positive direction. Path coefficient analysis revealed 100 flower bud weight and flower diameter to have high direct effect in positive direction. All the other characters affected the yield indirectly through these two characters, indicating that 100 floral bud weight and flower diameter could be taken as selection index.

Studies on the growth and development of Agropyron repens: interacting effects of humidity, calcium, and nitrogen on growth of the rhizome apex and lateral buds

A previous investigation of apical dominance in the rhizome of Agropyron repens showed that keeping the rhizome in a high humidity promoted the outgrowth of the lateral buds but strongly inhibited the growth of the rhizome apex. A study of these related responses demonstrated that the inhibition of apical growth was not prevented by excision of the lateral buds and was also induced when only the apex of the rhizome received the high humidity treatment. The necrotic lesions that developed in the arrested apices and the reduction of apical inhibition produced by various Ca treatments indicated that the inhibition of apical growth was caused by Ca deficiency. When the rhizome apex was exposed to low humidity, a localized high-humidity treatment of the lateral buds did not release the buds from apical dominance in low-N rhizomes but strongly promoted bud growth at a higher N level. When growth of the buds was induced at low humidity by increasing the N supply, the increase in bud weight was preceded by an increase in the water content of the bud when expressed on a dry weight basis. These results agree with those of previous investigations and suggest that the interacting effects of N and humidity on the water status of the buds may play a significant role in the mechanism of apical dominance.