scholarly journals Temperature Affects Leaf Unfolding Rate and Flowering of Cyclamen

HortScience ◽  
2001 ◽  
Vol 36 (2) ◽  
pp. 292-294 ◽  
Author(s):  
Meriam Karlsson ◽  
Jeffrey Werner
Keyword(s):  
Dry Weight ◽  
Similar Rate ◽  
Flower Number ◽  
Flower Buds ◽  
Open Flower ◽  
Leaf Unfolding ◽  
Response To Temperature ◽  
Relationship Of ◽  
The Relationship ◽  
Large Flower

The rate of leaf unfolding for Cyclamen persicum Mill. was determined at 8 to 24 °C. Temperature treatments started 9 weeks from seeding and after 8 weeks all plants were moved to 16 °C. The cultivars Miracle Salmon, Miracle Scarlet, and Miracle White produced leaves at a similar rate. The relationship of (leaves/d) = - 0.01727 - 0.02284 * °C + 0.005238 * (°C)2 - 0.000162 * (°C)3 (R2 = 0.99) best described the leaf unfolding rate in response to temperature. The maximum leaf unfolding rate was estimated to 0.329 leaves/day at 19.1 °C. Flower buds (2 mm diameter) developed within 60 days from the start of temperature treatments except at 8 °C. Thirty-five additional days at 16 °C were required for cyclamen initially grown at 8 °C for 8 weeks to produce flower buds. Despite similar conditions during bud development, flowering was delayed 14 to 18 days for plants initially grown at 24 °C compared to those grown at 12 to 20 °C. Plants initially at 8 °C did not flower within 70 days at 16 °C. Leaf and flower numbers at first open flower increased as initial temperature increased from 12 to 24 °C while dry weight and height only increased to 20 °C. No correlation between leaf unfolding and rate of flowering or flower number was detected. Recommendations for 20 °C during early cyclamen growth can be expected to support rapid rates of leaf unfolding and development, and large flower numbers.

Cyclamen Leaf Unfolding Rate in Response to Temperature

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 447d-447
Author(s):  
Meriam Karlsson ◽  
Jeffrey Werner
Keyword(s):  
Day Length ◽  
Leaf Number ◽  
Cyclamen Persicum ◽  
Flower Buds ◽  
Flower Bud ◽  
Leaf Unfolding ◽  
Significant Difference ◽  
Number Of Leaves ◽  
Growth Chambers ◽  
Response To Temperature

Nine-week-old plants of Cyclamen persicum `Miracle Salmon' were transplanted into 10-cm pots and placed in growth chambers at 8, 12, 16, 20, or 24 °C. The irradiance was 10 mol/day per m2 during a 16-h day length. After 8 weeks, the temperature was changed to 16 °C for all plants. Expanded leaves (1 cm or larger) were counted at weekly intervals for each plant. The rate of leaf unfolding increased with temperature to 20 °C. The fastest rate at 20 °C was 0.34 ± 0.05 leaf/day. Flower buds were visible 55 ± 7 days from start of temperature treatments (118 days from seeding) for the plants grown at 12, 16, or 20 °C. Flower buds appeared 60 ± 6.9 days from initiation of treatments for plants grown at 24 °C and 93 ± 8.9 days for cyclamens grown at 8 °C. Although there was no significant difference in rate of flower bud appearance for cyclamens grown at 12, 16, or 20 °C, the number of leaves, flowers, and flower buds varied significantly among all temperature treatments. Leaf number at flowering increased from 38 ± 4.7 for plants at 12 °C to 77 ± 8.3 at 24 °C. Flowers and flower buds increased from 18 ± 2.9 to 52 ± 11.0 as temperature increased from 12 to 24 °C. Plants grown at 8 °C had on average 6 ± 2 visible flower buds, but no open flowers at termination of the study (128 days from start of treatments).

Population variation in Sorghum halepense, Johnson grass, at the northern limits of its range

1984 ◽  
Vol 62 (9) ◽  
pp. 1781-1790 ◽  
Author(s):  
S. I. Warwick ◽  
B. K. Thompson ◽  
L. D. Black
Keyword(s):  
New York ◽  
Dry Weight ◽  
Population Variation ◽  
Sorghum Halepense ◽  
Johnson Grass ◽  
Allocation Patterns ◽  
Cultivated Species ◽  
Relationship Of ◽  
The Relationship ◽  
Enzyme Patterns

Thirteen populations of Sorghum halepense, Johnson grass, were sampled from fields in Ontario, Canada, and Ohio and New York, United States. Only four of these populations were reported to overwinter as rhizomes. The morphology, phenology, resource allocation patterns, and growth of seedling and mature plants of the overwintering and the non-overwintering populations were compared. Field-collected specimens from the nonoverwintering populations had wider culms and leaves and larger seeds and inflorescences. Analysis of material grown in a 5-month greenhouse trial indicated similar differences. Greenhouse plants from the nonoverwintering populations were also characterized by greater percent emergence, larger and faster growing seedlings, earlier flowering, larger culms and seeds, greater reproductive dry weight per plant, and about 1/10th the rhizome dry weight of overwintering plants. Differences between populations within a biotype were evident for both biotypes, although there was little within-population variation, except in rhizome production, where certain individuals of some nonoverwintering populations did not produce extended rhizomes. Among the five enzymes which were examined electrophoretically, only one, phosphoglucomutase (PGM), showed variable isozyme patterns. No differences in enzyme patterns were apparent between the overwintering and the nonoverwintering biotypes. The relationship of the nonoverwintering populations to the cultivated species, Sorghum bicolor and S. almum, an introgressant between S. halepense and S. bicolor, is discussed.

scholarly journals Flooding Reduces Gas Exchange and Growth in Snap Bean

HortScience ◽  
1991 ◽  
Vol 26 (4) ◽  
pp. 372-373 ◽  
Author(s):  
Bharat P. Singh ◽  
Kevin A. Tucker ◽  
James D. Sutton ◽  
Harbans L. Bhardwaj
Keyword(s):  
Gas Exchange ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Quadratic Model ◽  
Snap Bean ◽  
Blue Lake ◽  
Relationship Of ◽  
The Relationship ◽  
Best Fit ◽  
Prior Stress

This study was conducted to determine the effect of various flooding durations on the growth, water relations, and photosynthesis of the snap bean (Phaseolus vulgaris L.). Greenhouse-grown plants of cv. Blue Lake 274 were flooded for 0 (control), 1, 3, 5, or 7 days. Leaf water potential (ψ), stomatal conductance (gs), transpiration (E), and net photosynthesis (Pn) were measured at the completion of the flooding period and after recovery for 7 days. Root, stem, and leaf dry weights were recorded after plants were allowed to recover from the flooding stress for 7 days. The values for ψ, gs, E, and Pn decreased quadratically with the increase in the duration of flooding. The Pn of plants flooded for 1 day was 17% lower than that of the control and it reached near zero in plants flooded for 7 days. The decrease in Pn after 1 day of flooding was not associated with ψ or gs; however, for longer duration of flooding, Pn decline coincided with the decline in gs. A week after the cessation of flooding, the level of recovery in ψ, E, and Pn was linear and that in gs quadratic to the duration of prior stress experienced by the plant. However, after recovering for 7 days, none of the flooded plants regained gas exchange activities at par with the control. The relationship of stem dry weight to duration of flooding was linear, while a quadratic model provided the best fit for the regression of root and leaf dry weight on the number of days of flooding. Overall, even 1 day of flooding reduces photosynthesis in snap bean and causes a decrease in dry weight of the plant. the extent of decrease in both increasing with the duration of flooding.

scholarly journals Physical and mental relationships : an historical survey of the attempts to find a relationship between physical growth and intelligence, and physique and temperament

2022 ◽  
Author(s):  
◽  
Allan Albert Davison
Keyword(s):  
Similar Rate ◽  
The Other ◽  
Physical Growth ◽  
Historical Survey ◽  
Mind And Body ◽  
Relationship Of ◽  
The Relationship

The relationship of mind and body has long claimed man's attention. Early enquiries into the relationship of these two aspects of development have presumed that physical and mental growth were related functionally, that their growth proceeded together at a similar rate, and that any defect of one would immediately show itself in the other. The relationship occupied the minds of such men as Hippocrates, Plato and Aristotle, and many since have seen the relationship and guessed its nature.

scholarly journals The Relationship between Leaf Enclosure, Transpiration, and Upper Leaf Necrosis on Lilium `Star Gazer'

2004 ◽  
Vol 129 (1) ◽  
pp. 128-133 ◽  
Author(s):  
Yao-Chien Chang ◽  
William B. Miller
Keyword(s):  
Transpiration Rate ◽  
Flower Buds ◽  
Mechanical Perturbation ◽  
Leaf Unfolding ◽  
Ca Deficiency ◽  
Initial Symptoms ◽  
Young Leaves ◽  
Leaf Necrosis ◽  
The Relationship

Upper leaf necrosis (ULN) on Lilium `Star Gazer' has been shown to be a calcium (Ca) deficiency disorder. Initial symptoms of ULN tend to appear on leaf margins. Before flower buds are visible, young expanding leaves are congested and overlap each other on the margin. In the current study, we examined the relationship between leaf enclosure, transpiration, and upper leaf necrosis. We demonstrated that low transpiration rate and enclosure of young leaves played an important role in the occurrence of ULN. Young expanding leaves are low transpiration organs. The younger the leaf, the lower the transpiration rate and Ca concentration. Leaf enclosure further reduced transpiration of these young leaves and promoted ULN. Upper leaf necrosis was suppressed by manually unfolding the leaves using a technique we refer to as artificial leaf unfolding (ALU). ALU minimized leaf congestion, exposing leaves that were previously enclosed. We demonstrated that the effect of ALU was not the consequence of thigmomorphogenesis, as ULN was not reduced by mechanical perturbation in lieu of ALU. With ALU, transpiration of upper leaves was significantly increased and Ca concentration of the first leaf immediately below the flower buds was increased from 0.05% to 0.20%. We concluded that leaf enclosure promoted ULN occurrence, and ALU suppressed ULN primarily by increasing transpiration. The use of overhead fans to increase airflow over the tops of the plants significantly reduced both ULN incidence and severity.

The Respiratory Physiology of the Marine Nematodes Enoplus Brevis (Bastian) and E. Communis (Bastian)

1973 ◽  
Vol 59 (1) ◽  
pp. 255-266
Author(s):  
H. J. ATKINSON
Keyword(s):  
Oxygen Consumption ◽  
Body Size ◽  
Oxygen Tension ◽  
Dry Weight ◽  
Respiratory Physiology ◽  
Rate Of Oxygen Consumption ◽  
Oxygen Tensions ◽  
The Difference ◽  
Relationship Of ◽  
The Relationship

1. The rate of oxygen consumption of individual males of Enoplus brevis and E. communis was measured at 15 °C and at each of four oxygen tensions, 135, 75, 35, and 12 Torr, after at least 12 h experience of these conditions. 2. It was clearly demonstrated that the level of oxygen consumption of both species was reduced by each lowering of the imposed oxygen tension. 3. In all cases the oxygen consumption of each species fell with increasing body size. On a unit dry-weight basis the oxygen consumption of E. brevis is greater than that of the larger E. communis, but after allowing for the difference of body size the two species have more or less similar oxygen uptakes at all oxygen tensions. 4. In E. brevis oxygen tension influenced the relationship of body size and metabolism, the slope relating oxygen consumption and body weight becomes steeper with decreasing oxygen tension. This effect was not shown by E. communis. 5. Some general factors influencing the availability of oxygen to nematodes are considered.

Cyclamen Flower Development in Response to Temperature

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 447e-447
Author(s):  
Meriam Karlsson ◽  
Jeffrey Werner
Keyword(s):  
Flower Development ◽  
The Other ◽  
Day Length ◽  
Cyclamen Persicum ◽  
Flower Buds ◽  
Total Leaf Area ◽  
Open Flower ◽  
Number Of Leaves ◽  
Response To Temperature ◽  
Increasing Temperature

Commercially plug-produced Cyclamen persicum `Miracle Salmon' were transplanted into 10-cm pots 15 weeks from seeding and placed at 16 °C. The irradiance was 10 mol/day per m2 during a 16-h day length throughout the study. Three weeks from transplant, the plants were placed at 8, 12, 16, 20, or 24 °C. At the time of temperature change, flower buds were first visible. Time to first open flower decreased with increasing temperature to 20 °C. On average, the cyclamens grown at 20 °C required 60 ± 4.5 days from transplant (165 days from seeding) to first open flower. There was no difference in rate of flowering for the plants grown at 16 or 24 °C (74 ± 9.5 days from transplant). Cyclamens grown at 12 °C required on average 28 more days and cyclamens grown at 8 °C, 45 more days to first open flower compared to plants grown at 20 °C. There was no difference in number of leaves per plant (55 ± 14.4). However, the plants grown at 24 °C had significantly larger leaves and total leaf area per plant (1060 ± 235 cm2) than plants in the other temperature treatments (585 ± 104 cm2). The number of flowers and buds per plant was 45 ± 10.6 for plants grown at 16, 20 or 24 °C. Significantly less flowers and buds were produced by plants grown at 12 °C (34 ± 7.9) or 8 °C (17 ± 3.7).

scholarly journals Potential Role of Laccases in the Relationship of the Maize Late Wilt Causal Agent, Magnaporthiopsis maydis, and Its Host

2020 ◽  
Vol 6 (2) ◽  
pp. 63
Author(s):  
Ofir Degani ◽  
Yuval Goldblat
Keyword(s):  
Potential Role ◽  
Dry Weight ◽  
Maize Cultivars ◽  
Maize Plants ◽  
Relationship Of ◽  
The Relationship ◽  
Host Tissues ◽  
Adult Plants

Late wilt is a vascular disease of maize (Zea mays L.) caused by the soil-borne and seed-borne fungus Magnaporthiopsis maydis. The pathogen penetrates the roots of maize plants at the seedling stage, grows into the xylem vessels, and gradually spreads upwards. From the flowering stage to the kernel ripening, the fungal hyphae and secreted materials block the water supply in susceptible maize cultivars, leading to rapid dehydration and death. Laccase is an enzyme secreted by fungus for diverse purposes. The M. maydis laccase gene was identified in our laboratory, but under what conditions it is expressed and to what functions remain unknown. In the current study, we tested the influence of plant age and tissue source (roots or leaves) on M. maydis laccase secretion. The results show increasing laccase secretion as corn parts (as ground tissue) were added to the minimal medium (MM). Furthermore, roots stimulated laccase secretion more than leaves, and adult plants enhanced laccase secretion more than young plants. This implies the possibility that the richer lignin tissue of adult plants may cause increased secretion of the enzyme. In vitro pathogenicity assay proved the ability of M. maydis to develop inside detached roots of maize, barley, watermelon, and cotton but not peanut. Testing root powder from those plants in MM revealed a negative correlation between M. maydis growth (expressed as biomass) and laccase secretion. For example, while the addition of maize, barley, or cotton root powder led to increasing fungal dry weight, it also resulted in relatively lower laccase activity. Watermelon and peanut root powder led to opposite responses. These findings suggest a pivotal role of laccase in the ability of M. maydis to exploit and grow on different host tissues. The results encourage further examination and a deeper understanding of the laccase role in these interesting host–pathogen interactions.

scholarly journals Correlation between selected parameters of planting material and strawberry yield

2010 ◽  
Vol 22 (1) ◽  
pp. 9-12 ◽  
Author(s):  
Marcin Bartczak ◽  
Jolanta Lisiecka ◽  
Mikołaj Knaflewski
Keyword(s):  
Correlation Coefficients ◽  
Dry Weight ◽  
Fresh Weight ◽  
Planting Material ◽  
Whole Plant ◽  
Different Types ◽  
Positive Correlation Coefficient ◽  
Relationship Of ◽  
The Relationship ◽  
Strawberry Cultivars

Abstract The aim of this study was to determine the effect of fresh and dry weight, as well as the number and length of roots and number of crowns of different types of plants, on the yield of strawberry grown for the spring and autumn harvests. Three different types of frigo strawberry plants (waiting bed plants, plug plants, A+ plants) and two strawberry cultivars (‘Honeoye’ and ‘Elsanta’) were compared in the experiment. The plants were grown in polypropylene bags in an unheated glasshouse in the years 2002-2005. The correlation coefficients were calculated to estimate the relationship of the strawberry plants’ parameters to the yield quantity. An analysis of regression for the plant parameters that most significantly correlated to the strawberry yield was carried out, which determined that the fresh and dry weight of the strawberry plants, crown number, as well as length of roots were positively correlated to the quantity of the strawberry yield. The highest positive correlation coefficient was found for the fresh weight of a whole plant and the lowest one for the number of roots.

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