Total growth of a black spruce (Picea mariana) tree at Chalk River, Ontario, Canada

1969 ◽  
Vol 47 (1) ◽  
pp. 73-84 ◽  
Author(s):  
D. A. Fraser ◽  
D. McGuire

Apical and radial growth in trunk, branches, and roots, together with needle and cone distribution, were studied in a black spruce tree 31 years old and [Formula: see text] high. Growth of aerial parts was summarized as follows: (1) according to years of formation (oblique summation); (2) transversely on trunk inter-nodes (horizontal summation); and (3) according to the position of the annual rings, and the branch internodes (and needles) in relation to the pith or trunk (vertical summation). Root segments were classified on the basis of their diameter and distance from the trunk. Calculated on a dry-weight basis, the trunk accounted for 37%, the branches for 24%, the roots for 21%, and the needles for 18% of the grand total of 81 kg.The tree had 7.8 million needles when sampled in the fall of 1963, one-quarter of which were formed during the last 2 years of growth. Dry weight of individual needles varied with both position and age. While needles of the same season from the lower part of the crown exceeded those from the upper part in length, the reverse was true for the individual dry-weight content.In black spruce, cone periodicity, while distinct, is not as pronounced as in white spruce. The productive capacity of one "average" needle was estimated in terms of apical growth, trunk wood, and needle and root formation.


1964 ◽  
Vol 42 (2) ◽  
pp. 159-179 ◽  
Author(s):  
D. A. Fraser ◽  
L. Belanger ◽  
D. McGuire ◽  
Z. Zdrazil

Apical and radial growth in trunk and branches, and needle distribution were studied in a white spruce tree 11 meters high and 36 years old. Growth was summarized according to (1) years of formation (Oblique Summation), (2) transversely by trunk internodes (Horizontal Summation), and (3) position of the annual rings and branch internodes (and needles) relative to the pith or trunk respectively (Vertical Summation). In this study summations 1 and 3 were considered to reflect internal (nutritional and hormonal) controls of growth, whereas summation 2 represented the effect of environmental factors including periodicity of flower and seed formation.The tree studied possessed [Formula: see text] million needles when sampled in 1961, two-fifths of which were formed during the last 2 years of growth. The percentage of ash in the needles varied from 4 in the new needles to almost 8% in those 10 years old. The productive capacity of one "average" needle in terms of apical growth, trunk wood, and new needle formation was estimated.



1969 ◽  
Vol 112 (5) ◽  
pp. 787-794 ◽  
Author(s):  
R. H. Quarles ◽  
R. M. C. Dawson

1. The distribution of phospholipase D (phosphatidylcholine phosphatido-hydrolase, EC 3.1.4.4) was examined in the tissues of a number of plants and seeds. 2. The highest activities were found in various swollen storage tissues of certain plants: cabbage, central stalk; cauliflower, flower; celery, swollen leaf stalk; Kohl rabi, swollen stem; carrot, root; pea and marrow, seed. 3. Appreciable activity was retained in pea seeds for at least 1 year after drying. After germination and growth in the dark the total activity present in the cotyledons and also in the whole seedling decreased. 4. In the growing pea seedling (7 days old), about 3% of the total activity was in the plumule, 9% in the root and the remainder in the cotyledons. However, the activity in the root on a dry-weight basis was higher than that in the cotyledons. In both the root and the plumule the activity on a wet- or a dry-weight basis was highest in the growing tip. 5. The activity per dry weight in the roots and aerial parts of pea plants declined to low values as growth continued, but roots struck from cuttings of mature plants showed the same high activity as found in roots from young seedlings with cotyledons attached. 6. The total phospholipids present in the cotyledons of pea seeds were depleted on germination and growth. Of the individual phospholipids, phosphatidylcholine and phosphatidylethanolamine showed the same loss in 11 days as the whole phospholipid fraction, whereas phosphatidylinositol was decreased to a greater extent and cardiolipin and phosphatidylserine were not decreased. There was no increase of phosphatidic acid, as might have been expected if the phospholipids had disappeared through phospholipase D hydrolysis. 7. It is concluded that phospholipase D in plant storage tissues and seeds may be related to the rapid growth involved in their formation rather than being necessary for the utilization of their food reserve substances.



Two different genetic systems of incompatibility between pollen and style are known. One, heterogamety, depends upon the genotype of the individual pollen grain; the other, heterostyly, upon the genotype of its parent. We do not know whether the two types are physiologically related. The specificity of heterogamety indicates an immunity reaction. The effect of temperature on pollen-tube growth in the two systems was measured in order to discover their relationship. Compatible pollinations of both systems showed increased rate of growth with increased temperature until the lethal point was approached at about 35°C. Incompatible pollinations of both systems showed an optimum growth rate between 15 and 20°C. The physiological method of inhibition is therefore probably related although its genetic basis is different. The different rate of growth at different temperatures gives different total growth at in­hibition, and at the most favourable temperature there may be no inhibition at all. There is therefore no specific inhibitory zone in these plants, although elsewhere the top of the style may provide such a zone. Certain genotypes of Oenothera organensis show such powerful incompatibility that no temperature sensitivity can be discovered. This extreme modification is determined by the pollen parent’s genotype, like the main action in heterostyly. In heterostyled plants thrum pollen has to grow dowm the longer pin style; it is adapted to this in two ways. In Primula it is larger, in Linum grandiflorum it has a higher osmotic pressure. In either case, presumably, it has the higher dry weight. In two heterostyled Primula species thrum pollen grows faster dowm the long-pin style than pin pollen does down the short-thrum style. But in the illegitimate matings thrum pollen is more strongly inhibited. There is therefore a differentiation of the mechanism adapted to secure equal regularity of cross-fertilization of the two types.



Plants ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 310 ◽  
Author(s):  
Shakir Ullah ◽  
Jafar Khan ◽  
Khizar Hayat ◽  
Ahmed Abdelfattah Elateeq ◽  
Uzma Salam ◽  
...  

Trace metals (TM) contamination is a severe problem in the environment and produced an adverse effect on the productivity of crops. Cadmium (Cd) is a TM ranked seven among the top 20 pollutants due to its high toxicity and solubility in water, taken up by the plants and affects their growth and metabolism. In this study, we evaluated the growth, Cd accumulation and tolerance capacities of three chickpea (Cicer arietinum L.) cultivars (NC234 (NC2), ICCV89310 (IC8) and ICCV89323-B (IC8-B)), subjected to two Cd concentrations (25 and 50 µM) in hydroponic culture. The toxicity of Cd reduced the plant height and fresh and dry biomass in all cultivars. The maximum reduction was observed at 50 µM of Cd. Compared with IC8-B, cultivars IC8 and NC2 exhibited better performance with high growth, biomass, root to shoot (R/S) ratio and water content under high Cd stress. To measure the accumulation of Cd in root and shoot, an inductively coupled plasma optical emission spectrometer (ICP-OES) was used. IC8 and NC2 had comparatively high Cd tolerance and accumulation ability (> 100 µg g−1 dry weight), with IC8 being more tolerant and accumulated higher Cd in shoot than NC2, while cultivar IC8-B was sensitive. Root accumulated more Cd than shoot in a dose-dependent manner. The bioconcentration factors (BCF) and bioaccumulation coefficients (BAC) were far higher than one (> 1) and increased with an increase in Cd concentrations, while the translocation factor (TF) was less than one (< 1), suggesting that all the three cultivars were unable to transfer Cd from the root to the shoot efficiently. Our results indicated that IC8 and NC2 proved to be resistant, while IC8-B showed sensitivity when exposed to high Cd stress (50 µM).



2018 ◽  
Vol 6 (4) ◽  
pp. 359-365
Author(s):  
Sunil Kumar Chaudhary ◽  
Santosh Marahatta ◽  
Manisha Chaudhary

The weed is a major constraint of dry-direct seeded rice (DDSR) due to change in establishment methods and shifting weed flora towards competitive grasses and sedges. To minimize the weed density, its species and dry weight with brown manuring and for optimizing the yield of DDSR, the experiment was conducted during monsoon season of 2014 at Chitwan, Nepal. The experiment was done using a strip plot design to find the optimum seed rate and killing date of Sesbania under rice-Sesbania co-culture. Among different seed rates (60, 80, 100 kg ha-1) and knocking down days (21, 28, 35 & 42 DAS) of Sesbania, the optimum seed rate of Sesbania was 102 kg ha-1 and killing date was 32 days. The individual plot size was 5 x 4 m2. The growing of Sesbania with 100 kg seeds ha-1 along with its knocked down at 28 DAS was seen best to minimize the weeds having better performance of rice. The experiment clearly demonstrated the importance of brown manuring on effective control of weeds and on grain yield of rice under dry direct seeded rice. Int. J. Appl. Sci. Biotechnol. Vol 6(4): 359-365



1988 ◽  
Vol 18 (2) ◽  
pp. 188-194 ◽  
Author(s):  
Roberto Calamassi ◽  
Mauro Falusi ◽  
Laura Mugnai

The process of primary growth in 2-year-old seedlings of six Pinusbrutia Ten. provenances is described. At the end of the first growing season, two types of shoot morphology were observed: type 1, a terminal winter bud, and type 2, a terminal rosette of primary needles protecting the meristematic apex. During the 2nd year the seedlings exhibited a succession of shoots (varying in number from one to five), each of which was due to the elongation of a new apical bud. Morphological observations along with an anatomical examination of the winter bud led to the conclusion that the growth pattern in juvenile P. brutia is monocyclic with a variable number of summer shoots (using the terminology proposed by Lanner (Lanner, R.M. 1976. In Tree physiology and yield improvement. Editedby M.G.R. Cannell and F.T. Last. Academic Press, London, pp. 223-243)). The provenances studied differed both in growth potential and in seasonal growth pattern (differences in number of shoots, ratio of spring shoot to total growth, growth rate). Two groups could be identified: (i) the provenances of the island of Crete, which had a low growth potential and short growing season, and (ii) the high-altitude provenances of inland Turkey, with high growth potential and a growth rate that peaked in summer.



1941 ◽  
Vol 19d (12) ◽  
pp. 417-436 ◽  
Author(s):  
M. L. Prebble

Methods of sampling, determination of reproductive capacity, and analysis of data are described. Various physical measurements are positively correlated with reproductive capacity, but regression equations are unsatisfactory for estimation of fecundity outside of the population in which the relationships have been determined, due to variability in the degree of joint variation of size and fecundity under different feeding conditions. Field populations developed on white spruce are more fecund than those developed on black spruce; reductions of 30% or more may result from periodic food shortage.Reproductive capacity of females emerging over a period of three to five years in each of 20 populations, failed to show any consistent trend in relation to the diapause period. From this, and also from the slight reduction in eonymphal dry weight over extended intervals at favourable temperature, it is concluded that the destruction of eonymphal reserves during diapause proceeds very slowly and has no practical effect upon fecundity of females issuing after prolonged diapause.



2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
A. Vijayalakshmi ◽  
P. R. Kumar ◽  
S. Sakthi Priyadarsini ◽  
C. Meenaxshi

Aim. The present study aimed to isolate flavonoid fraction from the aerial parts ofCissus quadrangularisand to evaluate its antioxidant and anticancer potential usingin vitroassay system.Methods. Total phenolic and flavonoid contents were calculated for the drug. Flavonoid fraction was isolated using column chromatography and analysed using HPLC.In vitro, antioxidant activity of the ethanol extract and isolated flavonoid fraction was investigated by nitric oxide, DPPH and hydroxyl radical scavenging assays. Breast cancer (MCF 7) cell line was used as thein vitrocancer model for MTT assay.Result. The amount of total phenolic content and total flavonoid content in the ethanol extract showed 28.6 mg/g dry weight expressed as gallic acid equivalents, and 15.8 mg/g was expressed as quercetin equivalents, respectively. The tested extract showed good dose-dependent free radical scavenging property in all the models with the IC50values of 98 μg/mL, 125 μg/mL, and 96 μg/mL for ethanol extract and 10 μg/mL, 12 μg/mL, and 10 μg/mL for flavonoid fraction, respectively. The flavonoid fraction possess potent anticancer property against breast cancer cells (MCF7) with IC50value of 40 μg/mL.Conclusions. It can be concluded that the aerial part ofCissus quadrangularishas potential antioxidant and anticancer activities.



2015 ◽  
Vol 45 (5) ◽  
pp. 541-552 ◽  
Author(s):  
Rija Rapanoela ◽  
Frédéric Raulier ◽  
Sylvie Gauthier ◽  
Hakim Ouzennou ◽  
Jean-Pierre Saucier ◽  
...  

The capacity of a forest stand to produce timber is related to the interactions that exist between its regeneration capacity, physical site characteristics (climate, surficial deposit, drainage), and disturbances. Minimally, to be sustainably managed, a forest needs to be sufficiently productive and able to regenerate after a disturbance so that its productive capacity is maintained or enhanced. To this effect, we evaluated timber productivity over a large area (175 000 km2) covering the latitudinal extent of closed-canopy black spruce (Picea mariana (Mill.) B.S.P) forest. Site index and relative density index were used to identify stands that cannot reach a minimum volume of trees of minimum size over one rotation. A nonparametric method was used to estimate their values for all stands within the study area. This imputation used either physical site attributes alone to assess potential productivity independent of stand history or physical and vegetation site attributes to assess current productivity. The proportion of productive stands was then estimated at the scale of landscapes ranging from 39 to 2491 km2. Physical site factors alone explain 84% of the variability in the percentage of potentially productive stands (78% for currently productive stands); their combination resulted in an abrupt transition in productivity over the study area. However, burn rate alone also explains 63% of variation in the proportion of currently productive stands and 41% of the relative difference between percentages of potentially or currently productive stands. These results have implications for strategic forest management planning at land classification stage, as timber production area is assumed to remain stable through time, whereas it is apparently related to the disturbance rate.



1993 ◽  
Vol 57 (03) ◽  
pp. 447-453
Author(s):  
M. A. A. J. van Oijen ◽  
W. J. Koops ◽  
T. Zandstra ◽  
B. Kemp

AbstractA theoretical function is proposed which describes the individual weight-age relationship for foetuses in pigs. The function is based on total growth of the litter. A maximum uterus capacity, dependent on insemination weight of the sow, and a limitation of this capacity, dependent on litter size, is assumed. A modified Michaelis-Menten function is used as a basic growth function. The model was tested against experimental data and compared with four models from the literature. Goodness of fit, extrapolation outside the range of data, and biological interpretation of the parameters from the model were checked. A maximum uterus capacity of 20·3 kg for the average insemination weight of 119·0 kg was found. The inflexion point of the model was significantly (P&lt; 0·05) dependent on litter size.



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