Genetic variation in aspects of leaf growth of Populusclones, using the leaf plastochron index

1988 ◽  
Vol 18 (8) ◽  
pp. 1069-1077 ◽  
Author(s):  
R. Ceulemans ◽  
I. Impens ◽  
V. Steenackers
Keyword(s):  
Growth Rate ◽  
Production Rate ◽  
Growth Rates ◽  
Leaf Growth ◽  
Controlled Environment ◽  
Time Intervals ◽  
Leaf Production ◽  
Leaf Maturity ◽  
Regular Time ◽  
Plastochron Index

Leaf growth characteristics of seven clones of Populustrichocarpa, P. nigra, and interspecific hybrids with P. deltoides were examined on 1-year-old cuttings grown in a controlled-environment growth chamber. The plastochron index, a morphological time scale that is a linear function of time and correlated with other morphogenetic and physiological developmental processes, was applied to this development and growth study. Uniformity of leaf initiation was studied; new leaves were initiated at regular time intervals, at least under the controlled conditions of this study. Clones with a high leaf production rate (e.g., P. nigra clone Italica) had a low leaf growth rate and leaves reached maturity at a high leaf plastochron index (LPI 11). Fast-growing and high-yielding P. trichocarpa × P. deltoides hybrids showed the highest leaf growth rates and had a similar leaf production rate to P. trichocarpa. Despite considerable differences in leaf production rates, leaf maturity, and absolute leaf growth rates, only small differences in relative leaf growth rate were observed among the clones.

scholarly journals Effect of mechanical impedance on root and shoot growth of rice at time intervals

1970 ◽  
Vol 19 (2) ◽  
pp. 119-128
Author(s):  
AHMZ Ali
Keyword(s):  
Root Growth ◽  
Growth Rates ◽  
Shoot Growth ◽  
Leaf Growth ◽  
Mechanical Impedance ◽  
Growth Time ◽  
Time Interval ◽  
Night Time ◽  
Time Intervals ◽  
Root And Shoot Growth

In a phytotron chamber the effect of mechanical impedance on root and shoot growth of BR?29 variety of rice at different time intervals reaveled that length of the seminal axis and length of the longest leaf extended linearly in both unimpeded and impeded treatments. Diameter of roots increased in impeded treatment. The number of first order laterals also increased linearly with time in both unimpeded and impeded treatments. Although there were always significantly more laterals on the unimpeded root axes, lateral spacing does not show any tendency to change with time. Root growth rate was nearly half in impeded than in unimpeded treatment. The pattern of root length in unimpeded (UI) did not differ from that of the pattern in impeded (I) treatment as the ratios (I/UI) were more or less constant with time. The time of leaf appearance was delayed by one ? two days and leaf growth period was shortened by one day in impeded than in unimpeded treatment. Leaf growth rates did not differ significantly between day and night time although night time growth rates were always slightly less than day time. Key words: Mechanical impedance; Pattern of root growth; Time interval; Shoot growth; Rice DOI: http://dx.doi.org/10.3329/dujbs.v19i2.8953 DUJBS 2010; 19(2): 119-128

Effect of Temperature on Growth of Five Subtropical Grasses. I. Effect of Day and Night Temperature on Growth and Morphological Development

1978 ◽  
Vol 5 (2) ◽  
pp. 131 ◽  
Author(s):  
DA Ivory ◽  
PC Whiteman
Keyword(s):  
Growth Rate ◽  
Diurnal Variation ◽  
Constant Temperature ◽  
Growth Rates ◽  
Leaf Growth ◽  
Maximum Growth ◽  
Effect Of Temperature ◽  
Panicum Maximum ◽  
Morphological Development ◽  
Night Temperature

Cenchrus ciliaris, Chloris gayana, Panicum maximum var, trichoglume, Panicum coloratum var. makarikariense and Pennisetum clandestinum were grown in two experiments in controlled environments, each experiment having all possible day/night temperature combinations of (1) 10, 20, 30, and 40°C and (2) 15,25, 30 and 35°C. Both day and night temperatures significantly affected growth in all species. Growth was greatly restricted by constant temperatures of 10 and 15°, while maximum growth rates occurred at 29-35°C day temperatures with 26-30°C night temperatures. At optimum or supra-optimum temperatures a diurnal variation in temperature gave higher growth rates than a constant temperature for the same daily mean. By contrast, at suboptimum temperatures a constant temperature gave the highest growth rates and growth rate was decreased as the diurnal variation about a given daily mean temperature was increased. Mathematical functions relating the growth of each species to day and night temperature and maximum growth rate at optimum temperatures were developed. The effect of temperature on relative growth rate (Rw) was mediated through its effect on net assimilation rate (EA). Night temperature was found to affect Rw and EA independently of day temperature and therefore a prehistory effect of night temperature on photosynthesis in the subsequent day was indicated. Temperature had significant effects on tillering in P. maximum and P. clandestinum but had little effect in C. gayana, C. ciliaris and P. coloratum. The optimum temperatures for leaf growth and leaf area development in C. ciliaris and C. gayana were higher than the optimum temperatures for growth of the whole plant, while optimum temperatures for stem growth were lower. In P. maximum, P. coloratum and P. clandestinum, optimum temperatures for all growth components were similar. Differences between temperate and tropical grasses in morphological reaction to temperature are discussed.

Studies of grain production in Sorghum bicolor (L. Moench). V.* Effect of planting density on growth and yield

1975 ◽  
Vol 26 (1) ◽  
pp. 31 ◽  
Author(s):  
KS Fischer ◽  
GL Wilson
Keyword(s):  
Growth Rate ◽  
Grain Yield ◽  
Leaf Area ◽  
Growth Rates ◽  
Dry Matter ◽  
Leaf Growth ◽  
Crop Growth ◽  
Area Index ◽  
Crop Growth Rate ◽  
Net Assimilation

Growth analysis was applied to grain sorghum (cv. RS610) grown at low, medium and high population densities, i.e. 14,352, 143,520 and 645,836 plants ha-1 respectively. The medium densities had two arrangements of plants, square (S) and rectangular (R). Crop growth rates, inflorescence growth rates, leaf area indices, net assimilation rates and leaf growth rates were calculated from growth functions of plant dry matter and leaf area over time. Differences in crop growth rate between populations in the early stages were attributed to leaf area development—specifically to the initial leaf area (dependent on seedling number) and not to differences in leaf growth rates. Peak crop growth rates were 15.0, 27.5, 26.0 and 45.8 g m-2 day-1 for the low, medium (S), medium (R) and high populations respectively.The large difference between the growth rates of the medium (S) and the high populations was not explained by differences in the amount of radiation intercepted. Although leaf area indices were 4.6 and 10.2 respectively for the two populations, both canopies intercepted almost all of the noon radiation. Light extinction coefficients were 0.45 and 0.29 respectively. The relationship between net assimilation rate and leaf area index was such that for comparable leaf area indices above 2, plants at higher densities showed greater improvement in yield per unit increment in leaf area index. A maximum grain yield of 14,250 kg ha-1 was obtained at the high population density as a result of higher dry matter production, but a similar harvest index to that of the crops grown at the other densities. Inflorescence growth rate (g m-2 day-l) slightly exceeded crop growth rate in the latter part of grain filling, which indicated that there was some retranslocation to the grain of previously assimilated material. The maximum grain yield represents an efficiency of utilization of short-wave solar radiation during crop life of 2.5 x 10-6g cal-1. *Part IV, Aust. J. Agric. Res., 26: 25 (1975).

A temporal and morphological framework for flower development in Antirrhinum majus

2004 ◽  
Vol 82 (5) ◽  
pp. 681-690 ◽  
Author(s):  
Coral A Vincent ◽  
Enrico S Coen
Keyword(s):  
Growth Rate ◽  
Flower Development ◽  
Time Course ◽  
Similar Rate ◽  
Antirrhinum Majus ◽  
Time Intervals ◽  
Regular Time ◽  
Constant Rate ◽  
Phases Of Development ◽  
Bud Morphology

The entire course of flower development in Antirrhinum majus L., from initiation to maturity, is described in terms of regular time intervals. Floral meristem and bud morphology was determined by scanning electron microscopy for a sequence of 58 plastochrons. These can be grouped to define 15 stages or 7 phases of development, providing a temporal framework for gene expression and key morphological events, such as the formation of the complex corolla. The time course is also used to estimate overall growth rates of sepals and petals. Sepals initially grow at a constant rate, but growth rate gradually declines at later stages and sepal growth eventually arrests before flower development is complete. Petals initially grow at a similar rate to that of early sepals, but this growth rate is maintained for a longer period, accounting for the larger size of mature petals relative to sepals. Comparisons with Arabidopsis indicate that the duration of growth also makes an important contribution to variation in flower size.Key words: Antirrhinum, flower development, meristems, zygomorphy, developmental timing, petal.

Shoot and leaf growth in Fraxinuspennsylvanica and its relation to crown location and pruning

1994 ◽  
Vol 24 (10) ◽  
pp. 1997-2005 ◽  
Author(s):  
W.R. Remphrey ◽  
C.G. Davidson
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Leaf Growth ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Logistic Growth ◽  
Parameter Estimates ◽  
Regression Equations ◽  
Green Ash ◽  
Growth Duration

Elongation of shoots in various crown locations, and of individual internodes and leaves of the leading shoot, were recorded at 2-day intervals throughout the 1991 growing season in four clones of Fraxinuspennsylvanica var. subintegerrima (Vahl) Fern. (green ash). Other trees were disbudded and pruned to a single leader. Using a logistic growth function, nonlinear regression equations were generated and parameter estimates were used to determine maximum growth rates. Terminal leading shoots had a longer growth duration and a greater maximum growth rate than lateral shoots. The pruning treatment resulted in larger shoots, which grew 2–3 weeks longer and had a higher maximum growth rate. Leaf emergence occurred at regular intervals but the rate of emergence varied among clones. Leaf maximum growth rates were not significantly different among clones. Leaf size declined acropetally whereas internode length increased and then decreased. The longest leaves and internodes had the highest maximum growth rates. The size and maximum growth rates of putative preformed leaves were larger than putative neoformed leaves. As a shoot expanded, growth of one internode tended to cease during the linear phase of growth of its associated leaf and that of the succeeding internode.

The Influence of Salinity on Growth, Water Relations and Photosynthesis in Diplachne fusca (L.) P. Beauv. Ex Roemer & Schultes

1990 ◽  
Vol 17 (6) ◽  
pp. 675 ◽  
Author(s):  
BA Myers ◽  
TF Neales ◽  
MB Jones
Keyword(s):  
Growth Rate ◽  
Water Relations ◽  
Growth Rates ◽  
High Salinity ◽  
Leaf Growth ◽  
Intercellular Co2 Concentration ◽  
Carboxylation Efficiency ◽  
Initial Slope ◽  
Leaf Photosynthesis ◽  
Salinity Levels

The responses to increasing salintiy (in the range 0-420 mol m-3 NaCl) of an Australian accession of the halophytic grass, Diplachne fusca, have been studied in two experiments; in terms of growth, water relations, ion uptake and leaf photosynthesis. Twenty-one to 41 days after salinisation, plant dry weight, leaf area and relative growth rate were decreased at salinities at and above 300 mol m-3. Although salinity in the range 0-200 mol m-3 did not significantly affect growth rate, the highest value was at 200 mol m-3. Towards the end of the sampling period, a recovery of leaf growth rates was greater in plants at salinity levels of 90-200 mol m-3. The salt tolerance of this accession is similar to that reported for other populations of this species. As salinity in the root environment was increased, the osmotic potential of the leaf sap (Ψs) and the difference between leaf water potential and Ψs increased progressively with each harvest. There was no evidence that a lack of a capacity to adjust osmotically was related to the observed inhibition of growth at high salinity levels. It was confirmed that D. fusca possessed a C4 mode of leaf photosynthesis: the maximum assimilation rate (A) observed was high (>50 μmol m-2 s-1), the operating intercellular CO2 concentration (Ci) was approximately 140 μmol mol-1, the initial slope of the A v. CI curve ('carboxylation efficiency') was steep (1.24 μmol m-2 s-1) and the optimum leaf temperature for photosynthesis was approximately 45°C. At high salinities leaf conductance (g) was reduced by 78%. Using an analysis of A v. I and A v. CI relationships, the components of the 'photosynthetic capacity' of the mesophyll reduced by high salinity were Amax, carboxylation efficiency and photorespiration rate. There was no consistent relationship, at three salinity levels, between growth rates and Amax and carboxylation efficiency. It appears unlikely, therefore, that the primary inhibitory effects of salinity on growth are attributable to effects on leaf photosynthetic processes.

Phenotypic Plasticity of Chinese Sprangletop (Leptochloa chinensis) in Competition with Seeded Rice

2011 ◽  
Vol 25 (4) ◽  
pp. 652-658 ◽  
Author(s):  
Bhagirath S. Chauhan ◽  
David E. Johnson
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Production Rate ◽  
Tiller Number ◽  
Shoot Biomass ◽  
Assimilation Rate ◽  
Leaf Production ◽  
Relative Growth ◽  
Rice Plants ◽  
Net Assimilation

Chinese sprangletop, a C4species, is one of the most important grass weeds of seeded rice in Asia. Chinese sprangletop biology was studied by growing it alone and in competition with 4 and 12 rice plants. Rice competition did not affect the height of Chinese sprangletop, and the weed grew taller than rice, regardless of the competition. Compared with Chinese sprangletop grown alone, competition from rice reduced Chinese sprangletop leaf number, leaf production rate, tiller number, tiller production rate, leaf area, shoot biomass, relative growth rate, and net assimilation rate. Leaf area and shoot biomass of Chinese sprangletop when grown in competition with 12 rice plants was only 16% and 13%, respectively, of the leaf area and biomass of the weed grown alone.

Growth Rate and Biomass Leaf Production Of Thalassia hemprichii at Pengudang and Dompak Waters, Bintan Island

2021 ◽  
pp. 116-127
Author(s):  
Afis Irawan ◽  
Fadhliyah Idris ◽  
Aditya Hikmat Nugraha
Keyword(s):  
Growth Rate ◽  
Production Rate ◽  
Coastal Area ◽  
Sampling Method ◽  
Thalassia Hemprichii ◽  
Leaf Production ◽  
Leaf Type ◽  
Purposive Sampling ◽  
Rate Of Growth ◽  
Growth And Reproduction

Research on the rate of growth and reproduction of seagrass leaf type Thalassia hemprichii has been done in the waters of Pengudang and Dompak, Bintan Island. Aim this research for compare the growth rate and the production rate of Thalassia hemprichii biomass in Pengudang and Dompak coastal area, Bintan Island. The research was done by purposive sampling method, 30 individu seagrass leaves samples were taken using a plot measuring 50x50 centimeters. The results of the study were in the growth rate of the seagrass leaf type Thalassia hemprichii in the waters of Pengudang and Dompak 1.03 mm/day and 0.77 mm/day. Production rate of the Thalassia hemprichii leave biomass 0.07 gDW/m2 at Pengudang and 0.03 gDW/m2 at Dompak. Density of seagrass type Thalassia hemprichii 119.22 stands/m2 at Pengudang and 96.00 stands/m2 at Dompak. Based on test Two-Way ANOVA. There is no noticeable difference between the growth and production of the type of seagrass leaves Thalassia hemprichii in the waters of Pengudang and Dompak, Bintan Island.

scholarly journals Endogenous Abscisic Acid Concentrations, Vegetative Growth, and Water Relations of Apple Seedlings following PEG-induced Water Stress

1990 ◽  
Vol 115 (6) ◽  
pp. 991-999 ◽  
Author(s):  
Terence L. Robinson ◽  
Bruce H. Barritt
Keyword(s):  
Growth Rate ◽  
Abscisic Acid ◽  
Water Stress ◽  
Growth Rates ◽  
Shoot Growth ◽  
Leaf Growth ◽  
Turgor Pressure ◽  
Mature Leaves ◽  
Leaf Osmotic Potential ◽  
Shoot Growth Rate

In unstressed apple seedlings (Malus domestics Borkh.), concentrations of free abscisic acid (ABA) decreased in order from apical stem sections, immature expanding leaves, mature stem sections, and mature leaves. PEG-induced water stress stimulated a 2- to 10-fold increase in free ABA concentrations 1 day after treatment, depending on the amount of stress and the tissue. By the 3rd day of stress, free ABA concentrations were nearly the same as the unstressed treatment and remained low for the remainder of the 21-day stress period. Bound ABA concentrations were an order of magnitude lower than free ABA and were not influenced dramatically by water stress. Shoot growth rate, leaf expansion rate, and leaf emergence rate were reduced by water stress in relation to the severity of the stress; this reduction was associated with the initial increase in ABA. However, there was no increase in shoot or leaf growth rates associated with the decline in ABA concentrations by day 3 as growth rates remained depressed on water-stressed plants throughout the 21-day stress period. Water stress reduced evapotranspiration rate and midshoot leaf water potential (ψW)after 1 day, but leaf osmotic potential (ψS) adjusted more slowly, resulting in a loss of leaf turgor. The reduction in leaf turgor pressure (ψP) was highly correlated with decreased shoot growth rate and increased ABA concentrations on day 1 after treatment. By the 3rd day of water stress, ψP bad recovered even in the most severe treatment, and the recovery of turgor was associated with the drop in ABA concentrations. However, the increase in midshoot ψP and the decline in ABA were not associated with any increase in shoot growth rate. The continued inhibition of shoot growth was probably not related to ABA or turgor pressure of mature leaves but may have been related to turgor pressure in the growing tip.

Studies on the productivity of tropical pasture plants. I. Growth analysis, photosynthesis, and respiration of Hamil grass and Siratro in a controlled environment

1968 ◽  
Vol 19 (1) ◽  
pp. 35 ◽  
Author(s):  
MM Ludlow ◽  
GL Wilson
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Growth Rates ◽  
High Growth ◽  
Net Assimilation Rate ◽  
Controlled Environment ◽  
Assimilation Rate ◽  
Relative Growth ◽  
Net Assimilation ◽  
Photosynthesis And Respiration

Hamil grass and Siratro were grown as single plants in pots in controlled environment cabinets at a temperature favouring high growth rates and with adequate water and mineral nutrients. Leaf areas and dry weights of plant parts were recorded in two experiments, to which some of the plants were common. In the first experiment, weekly samples until 4 weeks from sowing provided data for the calculation of relative growth rates, net assimilation rates, and leaf area ratios. The relative growth rate of Hamil grass was almost twice that of Siratro and appears to be the highest yet recorded for any plant. The higher growth rate for the grass resulted from a high net assimilation rate, although the leaf area ratio was lower. The second experiment used Watson and Hayashi's method, in which plants are kept in darkness for a varying number of days to separate net assimilation rate into photosynthetic and respiratory components. Data were collected at 2 and 4 weeks from sowing. The high net assimilation rate of the grass was shown to result from a higher photosynthetic rate, despite a much greater respiration rate than in the legume. The technique used for estimating photosynthesis and respiration is discussed in relation to some of the assumptions that it makes.

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