Growth Analysis of the Effect of Phosphorus Nutrition on Seedings of Eucalyptus grandis

1992 ◽  
Vol 19 (1) ◽  
pp. 55 ◽  
Author(s):  
MUF Kirschbaum ◽  
DW Bellingham ◽  
RN Cromer
Keyword(s):  
Leaf Area ◽  
Specific Leaf Area ◽  
Carbon Fixation ◽  
Eucalyptus Grandis ◽  
Dry Weight ◽  
Plant Size ◽  
Phosphorus Concentration ◽  
Fixation Rate ◽  
Unit Leaf ◽  
Addition Rate

Eucalyptus grandis seedlings were grown in growth units in which plant roots were suspended in air while continuously being sprayed with nutrient solution (aeroponic system). Phosphorus was added to nutrient solutions in exponentially increasing amounts which determined plant growth. Phosphorus was added at five different relative addition rates. The proportion of dry matter in stems increased with plant size, but was independent of plant internal phosphorus concentration. In contrast, the ratio of root to leaf dry weight decreased almost 2-fold with increasing phosphorus concentration but changed little with plant size, and specific leaf area more than doubled with increasing phosphorus concentration. Carbon fixation rate per unit plant dry weight increased about 5-fold with increasing nutrient addition rate over the range of addition rates used. That increase was due to a doubling in specific leaf area and a doubling in assimilation rate per unit leaf area, while leaf weight as a fraction of total plant dry weight increased by about 20%.

scholarly journals Overexpressing the HD-Zip class II transcription factor EcHB1 from Eucalyptus camaldulensis increased the leaf photosynthesis and drought tolerance of Eucalyptus

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Keisuke Sasaki ◽  
Yuuki Ida ◽  
Sakihito Kitajima ◽  
Tetsu Kawazu ◽  
Takashi Hibino ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Leaf Area ◽  
Leucine Zipper ◽  
Eucalyptus Grandis ◽  
Eucalyptus Camaldulensis ◽  
Class Ii ◽  
Cell Multiplication ◽  
Leaf Photosynthesis ◽  
Unit Leaf

Abstract Alteration in the leaf mesophyll anatomy by genetic modification is potentially a promising tool for improving the physiological functions of trees by improving leaf photosynthesis. Homeodomain leucine zipper (HD-Zip) transcription factors are candidates for anatomical alterations of leaves through modification of cell multiplication, differentiation, and expansion. Full-length cDNA encoding a Eucalyptus camaldulensis HD-Zip class II transcription factor (EcHB1) was over-expressed in vivo in the hybrid Eucalyptus GUT5 generated from Eucalyptus grandis and Eucalyptus urophylla. Overexpression of EcHB1 induced significant modification in the mesophyll anatomy of Eucalyptus with enhancements in the number of cells and chloroplasts on a leaf-area basis. The leaf-area-based photosynthesis of Eucalyptus was improved in the EcHB1-overexpression lines, which was due to both enhanced CO2 diffusion into chloroplasts and increased photosynthetic biochemical functions through increased number of chloroplasts per unit leaf area. Additionally, overexpression of EcHB1 suppressed defoliation and thus improved the growth of Eucalyptus trees under drought stress, which was a result of reduced water loss from trees due to the reduction in leaf area with no changes in stomatal morphology. These results gave us new insights into the role of the HD-Zip II gene.

scholarly journals Fitness Cost of Imazamox Resistance in Wild Poinsettia (Euphorbia heterophylla L.)

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1859
Author(s):  
Saeid Hassanpour-bourkheili ◽  
Mahtab Heravi ◽  
Javid Gherekhloo ◽  
Ricardo Alcántara-de la Cruz ◽  
Rafael De Prado
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Specific Leaf Area ◽  
Dry Weight ◽  
Area Ratio ◽  
Fitness Cost ◽  
Seed Plant ◽  
Growth Indices ◽  
Relative Growth ◽  
Net Assimilation

Wild poinsettia (Euphorbia heterophylla L.) is a difficult-to-control weed in soybean production in Brazil that has developed resistance to herbicides, including acetolactate synthase inhibitors. We investigated the potential fitness cost associated to the Ser-653-Asn mutation that confers imazamox resistance in this weed. Plant height, leaf and stem dry weight, leaf area and seed production per plant as well as the growth indices of specific leaf area, leaf area ratio, relative growth rate and net assimilation in F2 homozygous resistant (R) and susceptible (S) wild poinsettia progenies were pairwise compared. S plants were superior in most of the traits studied. Plant heights for S and R biotypes, recorded at 95 days after planting (DAP), were 137 and 120 cm, respectively. Leaf areas were 742 and 1048 cm2 in the R and S biotypes, respectively. The dry weights of leaves and stems in the S plants were 30 and 35%, respectively, higher than in the R plants. In both biotypes, the leaves had a greater share in dry weight at early development stages, but from 50 DAP, the stem became the main contributor to the dry weight of the shoots. The R biotype produced 110 ± 4 seed plant−1, i.e., 12 ± 3% less seeds per plant than that of the S one (125 ± 7 seed plant−1). The growth indices leaf area ratio and specific leaf area were generally higher in the S biotype or similar between both biotypes; while the relative growth rate and net assimilation rate were punctually superior in the R biotype. These results demonstrate that the Ser-653-Asn mutation imposed a fitness cost in imazamox R wild poinsettia.

Observations of the Photosynthetic Physiology of Tree Species within the C3 Monocotyledon Genus Pandanus, and Comparison with Dicotyledon C3 Tree Species

1998 ◽  
Vol 46 (1) ◽  
pp. 103 ◽  
Author(s):  
Catherine E. Lovelock
Keyword(s):  
Leaf Area ◽  
Specific Leaf Area ◽  
Tree Species ◽  
Dark Respiration ◽  
Dry Weight ◽  
Weight Basis ◽  
Growth And Survival ◽  
Respiration Rates ◽  
Leaf Dark Respiration ◽  
Resource Levels

Photosynthetic characteristics of tree species from the tropical C3 monocotyledon genus Pandanus were compared with C3 dicotyledon species growing in similar environments. The Pandanus species had similar maximum photosynthetic rates (Amax) to dicotyledon tree species in leaves from both sun and shaded environments when Amax was expressed on an area basis. Because of the low specific leaf area of the schlerophyllous leaves of the Pandanus compared to the dicotyledon species, the similarity in Amax was no longer evident when Amax was expressed on a dry-weight basis. Leaf dark respiration rates of the Pandanus on a leaf area and weight basis were generally lower than the shade-intolerant dicotyledons and similar to the shade-tolerant dicotyledon species. Low dark respiration rates and low specific leaf area of the Pandanus may be important characteristics for growth and survival in environments where resource levels are low and the likelihood of tissue damage is high.

Recruitment and life-history traits of sparse plant species in subalpine grasslands

2003 ◽  
Vol 81 (2) ◽  
pp. 171-182 ◽  
Author(s):  
Gunnar Austrheim ◽  
Ove Eriksson
Keyword(s):  
Leaf Area ◽  
Negative Correlation ◽  
Specific Leaf Area ◽  
Seedling Recruitment ◽  
Plant Traits ◽  
Dry Weight ◽  
Community Diversity ◽  
Safe Sites ◽  
Subalpine Grasslands ◽  
Leaf Dry Weight

Recruitment is critical for the maintenance of plant populations and community diversity, but sexual regeneration is considered to be infrequent in climatically harsh habitats such as subalpine grasslands. This study examines the importance of regeneration through seed for 16 sparse herb species, and we asked whether their populations are limited by safe sites or the availability of seeds. Seedling recruitment and winter survival were recorded after sowing in an experimental split-plot design in (i) pasture grazed by livestock, and (ii) exclosed grassland cultivated for annual mowing. In addition we examined the effect of disturbance and local seedbank recruitment. All species were able to recruit and survive the first winter in at least some of the experimental plots, although none were initially present. Recruitment mainly occurred in disturbed plots, and disturbed pasture plots had a significantly higher recruitment than disturbed exclosures for all species except Silene dioica. We further examined whether specific plant traits were related to variation in recruitment. Lower recruitment in the disturbed exclosure was associated with higher specific leaf area, leaf dry weight, and seed number. In contrast, seeds sown in disturbed pasture recruited more independently of species traits. The exception was a negative correlation between recruitment and leaf dry weight, and an unexpected negative correlation with seed weight. We suggest that recruitment differences among habitats mainly reflect lower humidity in the exclosure. Consequently, small stature plants with small specific leaf area should have the highest recruiting probability when exposed to drought. The almost exclusive recruitment on disturbed plots indicates a strong competitive effect on the target species in vegetated plots, and suggests that safe sites for regeneration through seed are rare in subalpine grasslands.Key words: colonization, herbs, plant abundance and distribution, disturbance, pastures, cultivated exclosures, sowing experiment.

Growth and development at cold-hardening temperatures. Pigment and benzoquinone accumulation in winter rye

1985 ◽  
Vol 63 (4) ◽  
pp. 716-721 ◽  
Author(s):  
Marianna Krol ◽  
Norman P. A. Huner
Keyword(s):  
Leaf Area ◽  
Fold Increase ◽  
Dry Weight ◽  
Cold Hardening ◽  
Carotenoid Content ◽  
Winter Rye ◽  
Warm Temperature ◽  
Leaf Ontogeny ◽  
Unit Leaf ◽  
Area Basis

Accumulation of chlorophyll, the carotenoids (β-carotene, lutein, violaxanthin, and neoxanthin), and the benzoquinones (plastoquinone A and α-tocopherol) were monitored in 'Puma' rye as a function of leaf ontogeny at warm and cold-hardening temperatures. Although the kinetics of accumulation differed among the leaves of warm-grown plants, the initial and maximum levels of the pigments and benzoquinones expressed on a leaf area basis did not differ significantly among the first four leaves of the main culm. In contrast, the third and fourth leaf of cold-grown plants, which developed completely at the low temperature, generally exhibited initial and maximum pigment and benzoquinone levels 60–300% greater than was observed for leaf 1 and 2 of cold-grown plants, which were completely or partially developed at the warm temperature regime. This resulted in pigment and benzoquinone levels which were 1.6- to 3-fold greater in the plants grown at cold-hardening temperatures than those grown at the warm temperature, when expressed on a per unit leaf area basis. However, when pigment accumulation was calculated on a chlorophyll basis, the benzoquinone content of leaves that developed solely at cold-hardening temperatures exhibited a 1.7-fold increase over the same leaves developed at warm temperatures. Carotenoids did not exhibit this trend. Calculations based on chlorophyll/carotenoid content and dry weight accumulation indicated that leaves that were developed at cold-hardening temperatures appeared to produce more dry matter per unit of photosynthetic pigments than the same leaves that were developed at nonhardening temperatures.

scholarly journals Relationship among specific leaf area, leaf nitrogen, leaf phosphorus and photosynthetic rate in herbaceous species of tropical dry deciduous in Vindhyan highlands

2017 ◽  
Vol 6 (2) ◽  
pp. 1531 ◽  
Author(s):  
Prajjwal Dubey ◽  
Raghubanshi A. S. ◽  
Anil K. Dwivedi*
Keyword(s):  
Leaf Area ◽  
Photosynthetic Rate ◽  
Specific Leaf Area ◽  
Pearson Correlation ◽  
Colorimetric Method ◽  
Correlation Coefficients ◽  
Ground Level ◽  
Dry Weight ◽  
Leaf Nitrogen ◽  
Herbaceous Species

A range of leaf attributes was measured for 17 herbaceous species in four contrasting habitats fortnightly from July to September during 2996-2007. All herbaceous vegetation in 5 randomly located plots within each of four sites were clipped at ground level and analyzed fortnightly. Leaf area was recorded by the leaf area meter (Systronics; Leaf area meter- 211). Fresh leaves were dried at 80o C for 48 hr to estimate their dry weight. Specific Leaf Area (SLA) was determined as ratio of leaf area to leaf dry weight. Leaf nitrogen was measured by Kjeldahl method and phosphorus by phosphomolybdic blue colorimetric method. The obtained values were subjected to Two- tailed Pearson correlation coefficients using SPSS (2004 ver. 13) package. SLA, leaf nitrogen, leaf phosphorus and photosynthetic rate show positive relationship with each other.

scholarly journals Growth Analysis and Photosynthesis Measurements of Cucumber Seedlings Grown under Light with Different Red to Far-red Ratios

HortScience ◽  
2016 ◽  
Vol 51 (7) ◽  
pp. 843-846 ◽  
Author(s):  
Toshio Shibuya ◽  
Ryosuke Endo ◽  
Yoshiaki Kitaya ◽  
Saki Hayashi
Keyword(s):  
Leaf Area ◽  
Growth Parameters ◽  
Weight Ratio ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Unit Leaf Area ◽  
Cucumber Seedlings ◽  
Unit Leaf ◽  
Net Assimilation ◽  
Normal Light

Light with a higher red to far-red ratio (R:FR) than sunlight reduces plant growth, but the cause has not been firmly established. In the present study, cucumber seedlings were grown under normal light (similar to sunlight; R:FR = 1.4) from metal-halide lamps or high-R:FR light (R:FR = 4.3) created by transmitting their light through FR-absorbing film, and then their growth parameters and photosynthesis were compared. The relative growth rate (RGR) at high R:FR was 92% of that under normal R:FR, although the net assimilation rate (NAR) did not differ between the treatments, indicating that changes in net photosynthesis per unit leaf area did not cause the growth inhibition at high R:FR. The CO2 exchange per unit leaf area did not differ between the treatments, which supports this hypothesis. The leaf area ratio (LAR) of total plant dry weight of high R:FR seedlings to that of normal R:FR seedlings was also 92%. This suggests that growth suppression in the high R:FR seedlings was caused mainly by decreased LAR. The specific leaf area (SLA) and leaf weight ratio (LWR), components of LAR, under high-R:FR light were 89% and 105%, respectively, of those under normal light, indicating that the smaller LAR at high R:FR mainly results from suppressed leaf enlargement per unit leaf dry matter.

scholarly journals THE IMPACT OF LIGHT PENETRATION INTO CANOPY AND SEASONALITY ON PHOTOSYNTHETIC INDICES IN APPLE TREE LEAVES

AGROFOR ◽  
2019 ◽  
Vol 4 (3) ◽  
Author(s):  
Giedrė SAMUOLIENĖ ◽  
Kristina LAUŽIKĖ ◽  
Nobertas USELIS
Keyword(s):  
Leaf Area ◽  
Specific Leaf Area ◽  
Apple Tree ◽  
Weight Ratio ◽  
Dry Weight ◽  
Light Penetration ◽  
Fresh Weight ◽  
Photochemical Reflectance Index ◽  
Plant Senescence ◽  
The Impact

The aim of this study was to analyse the impact of light penetration into canopy and the effect of distances between technological tools and seasonality on photosynthetic behaviour. Apple tree cultivar ‘Auksis’ was grafted onto superdwarfing rootstock P22 and planted at different distances (from 0,25 m to 1 m in rows, while space between rows was 3 m). Photochemical reflectance and plant senescence reflectance indices were measured at two heights: 1.0 – 1.2 m above ground and 1.8 – 2.0 m above ground; specific leaf area, fresh and dry weight were evaluated from all the canopy. Strong positive correlations were determined between photochemical reflectance index and plant senescence reflectance index in higher and lower levels of the canopy. Strong negative correlations were determined between photochemical reflectance index and plant senescence reflectance index and between specific leaf area and dry and fresh mass ratio. Increasing density between apple trees from 1 m to 0.5 m led to increase in photochemical reflectance index and specific leaf area, but plant senescence reflectance index decreased. Meanwhile, seasonality had significant impact on specific leaf area formation and dry to fresh weight ratio. Dry and fresh weight ratio increased by 5% in autumn compared to summer. Our results indicated that with decreased light penetration into canopy photochemical reflectance index decreased, but plant senescence reflectance index increased. Moreover, in autumn, trees prepare for winter by storing more nutrients and leaves accumulate more dry mass.

scholarly journals Effect of Extended Photoperiod with a Fixed Mixture of Light Wavelengths on Tomato Seedlings

HortScience ◽  
2020 ◽  
Vol 55 (11) ◽  
pp. 1832-1839
Author(s):  
Humberto Aguirre-Becerra ◽  
Juan Fernando García-Trejo ◽  
Cristina Vázquez-Hernández ◽  
Aurora Mariana Alvarado ◽  
Ana Angélica Feregrino-Pérez ◽  
...  
Keyword(s):  
Leaf Area ◽  
Specific Leaf Area ◽  
Negative Impact ◽  
Biomass Accumulation ◽  
Dry Weight ◽  
Artificial Light ◽  
Health Index ◽  
Ultraviolet A ◽  
Tomato Seedlings ◽  
Leaf Dry Weight

Light is an abiotic factor, and its quality, quantity, and photoperiod can be modulated to work as eustress inductors to regulate plant processes. It is known that red (R), blue (B), far-red (FR), and ultraviolet-A wavelengths can promote photomorphogenesis and secondary metabolite production in plants. Several ratios of R:B and the addition of end of-day FR, separately, have beneficial effects on plant development, whereas adding ultraviolet-A enhances the production of secondary metabolites such as phenols. However, the effects of extended photoperiods with a mixture of these four wavelengths and extra end-of-day FR have not been evaluated for plants of commercial interest. The objective of this study was to determine the effects on tomato seedlings (‘Saladette’, CORDOBA F1) of different overnight photoperiods using a fixed combination of R (625 nm), B (460 nm), FR (720 nm), and ultraviolet-A (410 nm). We expected increases in the production of specialized metabolites and the generation of beneficial changes in the seedling biomass and morphology. Four treatments involving overnight artificial light provided by a light-emitting diode (LED) module were established: TC (control), 0 h; T1, 4 hours; T2, 8 hours; and T3, 12 hours. All treatments were subjected to a 12-hour natural photoperiod and 12 hours of overnight artificial light. The experiment lasted 4 weeks, and plants were sampled every week for physical and phytochemical measurements. In general, seedlings subjected to 4-hour and 8-hour treatments presented better results than those subjected to the control and 12-hour overnight photoperiod treatments. Seedlings subjected to treatments with an 8-hour overnight photoperiod presented large accumulation of biomass in the stem rather than in the leaves because they had large stem dry weight, stem weight, and elongation and higher first, second, and third internode lengths; however, they had lower leaf area, leaf dry weight, and health index. Seedlings subjected to treatment with a 4-hour overnight photoperiod were visually bigger, with large leaf expansion, total length, stem weight, total weight, and specific leaf area; however, this treatment had a negative impact on the biomass accumulation, with lower leaf weight, stem dry weight, and health index. The 12-hour treatment had a negative impact on the leaf area, and thus the specific leaf area, of seedlings; however, the biomass accumulation was large, with higher leaf dry weight, total dry matter, and specific leaf area, but no difference in stem dry weight compared with the control. At the end of the experiment, the total phenolic content increased in all treatments compared with the control, but the flavonoid content decreased. Moreover, the antioxidant capacity was higher for T2 during the last 2 weeks of the experiment. Results are discussed according to the possibilities of using this light strategy for seedling production.

Sign in / Sign up

Export Citation Format

Share Document