Changes in growth, leaf abscission, and biomass associated with seasonal tropospheric ozone exposures of Populustremuloides clones and seedlings

1996 ◽  
Vol 26 (1) ◽  
pp. 23-37 ◽  
Author(s):  
D.F. Karnosky ◽  
Z.E. Gagnon ◽  
R.E. Dickson ◽  
M.D. Coleman ◽  
J.G. Isebrands ◽  
...  

The effects of single-season tropospheric ozone (O3) exposures on growth, leaf abscission, and biomass of trembling aspen (Populustremuloides Michx.) rooted cuttings and seedlings were studied. Plants were grown in the Upper Peninsula of Michigan in open-top chambers with O3 exposures that ranged from 7 to 92 ppm-h. Depending on the genotype, total seasonal O3 exposure in the range of 50–92 ppm-h had negative impacts on stem, retained leaf, and root biomass accumulation and on diameter growth. Leaf abscission generally increased with increasing O3 exposure and was the principal cause of the decrease in leaf biomass of the O3-treated plants. Considerable genetic variation in O3 responses occurred, as shown by differences in sensitivities among clones and among seedlings. However, the responses to O3 of rooted cuttings and seedlings were similar when seedling means were compared with clonal means for leaf abscission, diameter growth, retained leaf biomass, and root biomass. Comparison of a single square-wave treatment (52 ppm-h) with 70 and 92 ppm-h episodic exposures suggested that the plant response to the square-wave exposure was similar to the response to the highest episodic exposure even though the 92 ppm-h episodic exposure was almost twice the square-wave exposure. Our results are consistent with previous studies that show that P. tremuloides is highly responsive to O3 exposure and this response has a strong genetic component.

2018 ◽  
Vol 28 (3) ◽  
pp. 378-381
Author(s):  
Bryan J. Peterson ◽  
Stephanie E. Burnett ◽  
Olivia Sanchez

Although overhead mist revolutionized the propagation industry, it does suffer from potential drawbacks that include the application of large volumes of water, potentially unsanitary conditions, irregular misting coverage, and leaching of foliar nutrients. We explored the feasibility of submist as an alternative as it might avoid these problems by applying water exclusively from below the cutting, which is inserted basally into an enclosed rooting chamber. We propagated cuttings of korean lilac (Syringa pubescens ssp. patula) and inkberry (Ilex glabra) using both overhead mist and submist to compare effectiveness of the systems. Cuttings of korean lilac were wounded and dipped basally into 8000 mg·L−1 of the potassium salt of indole-3-butyric acid (K-IBA), and those in the overhead mist systems were inserted into coarse perlite. Cuttings of inkberry were wounded and treated with 5000 mg·L−1 K-IBA, and those in the overhead mist systems were inserted into 50:50 peat:perlite (by vol). Cuttings of korean lilac in the submist systems produced more than twice as many roots as cuttings in the overhead mist systems, with roots more than 2.6 times the length. Similarly, cuttings of inkberry in the submist systems produced more than three times the root counts and root lengths as cuttings in the overhead mist systems. For korean lilac, root dry weights averaged 58 mg for cuttings in the submist system, compared with only 18 mg among cuttings receiving overhead mist. Likewise, root dry weights averaged 70 and 7 mg for cuttings of inkberry propagated by submist and overhead mist, respectively. Rooted cuttings of korean lilac transplanted well into a soilless substrate, where they more than tripled their root biomass to 218 mg (vs. 59 mg for cuttings transplanted from overhead mist). We did not evaluate transplant performance of inkberry. Our results show that submist systems might merit consideration for the propagation of woody plants by leafy stem cuttings.


2020 ◽  
Vol 38 (1) ◽  
pp. 103
Author(s):  
Fernando Abasolo Pacheco ◽  
Boris Bonilla Montalván ◽  
Cesar Bermeo Toledo ◽  
Yarelys Ferrer Sánchez ◽  
Andy Jafet Ramirez Castillo ◽  
...  

Agrochemical use in horticultural cultivations generates negative effects, thus the need for searching to decrease or eliminate its use by means of other less toxic techniques. Agricultural homeopathy represents an alternative for ecological agriculture, impacting positively in cultivation development. The effect of four homeopathic medicines for human use were assessed in two centesimal dynamizations (7CH and 13CH) [(Silicea Terra (SiT), Natrum muriaticum (NaM), Zincum phosphoricum (ZiP) and Phosphoricum acidum (PhA)], and a control treatment (distilled water) on tomato plant germination, emergence, and initial development. The treatments were established under a randomized complete block design with three repiclates. Germination and emergence rate and percentage and morphometric variables (plant height, radicle length, dry and wet weight) were assessed, including the variables in stem diameter and wet and dry leaf weight, number of branches, leaves, and buds in the vegetative development stage. Signif icant differences were observed in all the morphometric variables assessed in function of the different development stages, homeopathic medicines, and their different dynamizations. During germination, greater growth in stem length was observed with ZiP-7CH (5.5 ± 0.98 cm) compared to the control group (4.3 ± 1.10 cm). During the emergence stage, the treatments SiT-7CH (6.6 ± 1.11 cm) and ZiP-7CH (5.9 ± 1.41 cm) increased stem length signif icantly whereas with PhA-7CH, the best effects were obtained in the variables assessed during the vegetative development stage, LT (94 ± 8.31 cm), leaf number (No hojas) (131 ± 27.71), fresh stem biomass (BFT) (17.20 ± 2.45 g), wet leaf biomass (BFH) (30 ± 7.72 g), dry leaf biomass (BSH) (2 ± 0.61 g), fresh root biomass (BFR) (10 ± 6.26 g), dry root biomass (BSR) (1 ± 0.43 g), and number of flower buds (No H) (6 ± 7.10). The homeopathic medicines applied impacted positively during the initial and vegetative development stages of tomato under controlled conditions. This research study represents and advance in the sustainable management of tomato cultivation.


2015 ◽  
Vol 34 (3) ◽  
pp. 867-880 ◽  
Author(s):  
David Lévesque ◽  
Christiane Hudon ◽  
Jean-Pierre Amyot ◽  
Antonella Cattaneo

2020 ◽  
Vol 11 ◽  
Author(s):  
Khondoker M. G. Dastogeer ◽  
Mst Ishrat Zahan ◽  
Md. Tahjib-Ul-Arif ◽  
Mst Arjina Akter ◽  
Shin Okazaki

Soil salinity often hinders plant productivity in both natural and agricultural settings. Arbuscular mycorrhizal fungal (AMF) symbionts can mediate plant stress responses by enhancing salinity tolerance, but less attention has been devoted to measuring these effects across plant-AMF studies. We performed a meta-analysis of published studies to determine how AMF symbionts influence plant responses under non-stressed vs. salt-stressed conditions. Compared to non-AMF plants, AMF plants had significantly higher shoot and root biomass (p < 0.0001) both under non-stressed conditions and in the presence of varying levels of NaCl salinity in soil, and the differences became more prominent as the salinity stress increased. Categorical analyses revealed that the accumulation of plant shoot and root biomass was influenced by various factors, such as the host life cycle and lifestyle, the fungal group, and the duration of the AMF and salinity treatments. More specifically, the effect of Funneliformis on plant shoot biomass was more prominent as the salinity level increased. Additionally, under stress, AMF increased shoot biomass more on plants that are dicots, plants that have nodulation capacity and plants that use the C3 plant photosynthetic pathway. When plants experienced short-term stress (<2 weeks), the effect of AMF was not apparent, but under longer-term stress (>4 weeks), AMF had a distinct effect on the plant response. For the first time, we observed significant phylogenetic signals in plants and mycorrhizal species in terms of their shoot biomass response to moderate levels of salinity stress, i.e., closely related plants had more similar responses, and closely related mycorrhizal species had similar effects than distantly related species. In contrast, the root biomass accumulation trait was related to fungal phylogeny only under non-stressed conditions and not under stressed conditions. Additionally, the influence of AMF on plant biomass was found to be unrelated to plant phylogeny. In line with the greater biomass accumulation in AMF plants, AMF improved the water status, photosynthetic efficiency and uptake of Ca and K in plants irrespective of salinity stress. The uptake of N and P was higher in AMF plants, and as the salinity increased, the trend showed a decline but had a clear upturn as the salinity stress increased to a high level. The activities of malondialdehyde (MDA), peroxidase (POD), and superoxide dismutase (SOD) as well as the proline content changed due to AMF treatment under salinity stress. The accumulation of proline and catalase (CAT) was observed only when plants experienced moderate salinity stress, but peroxidase (POD) and superoxide dismutase (SOD) were significantly increased in AMF plants irrespective of salinity stress. Taken together, arbuscular mycorrhizal fungi influenced plant growth and physiology, and their effects were more notable when their host plants experienced salinity stress and were influenced by plant and fungal traits.


2017 ◽  
Vol 19 (1) ◽  
pp. 28
Author(s):  
Retno Bandriyati Arni Putri ◽  
Trijono Djoko Sulistyo ◽  
Chairul Anwar

<p>The increase of oyster mushroom farmers in wonogiri will be impact immediately on increasing waste baglog. One of the utilization is to be medium on hydroponic substrate for growing mustard greens and it will combined with charcoal and various types of nutrients. The research was conducted from October to December 2015 at the Greenhouse C and Laboratory EMPT UNS.the research employed completely random design (CRD) with two factor that is ratio of medium and various types of nutrients. The result of research showed that interaction between ratio of medium and various types affected significantly  the parameters of leaf area, leaf fresh weight and leaf biomass. Root fresh weight, root volume, root length and root biomass is only influenced by the type of nutrition with the ab mix is the most good in improving and supplying nutrients</p>


Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1686
Author(s):  
Haoyun Wang ◽  
Feng Wu ◽  
Min Li ◽  
Daqu Liang ◽  
Guijie Ding

Pines have heteroblastic foliage (primary and secondary needles) during seedling stage, but how heteroblastic foliage affects carbon storage and biomass accumulation, contributing to seedling quality, is unclear. We investigated the influences of heteroblastic foliage on photosynthetic physiological characteristics, non-structural carbohydrate (NSC) and biomass accumulation in current-year seedlings; the key factors determining biomass accumulation were mainly determined by principal component screening, Spearman correlation, and path analysis. The results indicated that (1) primary needles have high photosynthetic pigments (chlorophyll a and total chlorophyll), net photosynthetic rates (Pn), the potential maximum photochemical efficiency (Fv/Fm), and leaf instantaneous water use efficiency (WUEi), whereas higher non-photochemical quenching (NPQ) suggested that sudden light increases induce the initiation of quenching mechanism in primary needles; additionally, secondary needles had a lower transpiration rate (Tr), limiting stomata (Ls), and light saturation point. (2) Secondary needles promoted soluble sugar (fructose and glucose) increases in leaves compared to that of primary needles and increased the leaf biomass accumulation (from 47.06% to 54.30%), enhancing the overall ability of photosynthetic organs; additionally, secondary needles can enhance the proportion of starch storage in the roots, and NSC accumulation was significantly increasing in the seedling leaves and roots. (3) Photosynthetic pigments (carotenoids, chlorophyll a, and total chlorophyll) had direct positive effects on primary needle seedling (PNS) biomass and promoted biomass by indirectly increasing soluble sugar synthesis in the stems. The Pn was the main physiological factor determining PNS biomass accumulation. In addition, the WUEi, Ls, and NPQ had direct negative effects on PNS biomass accumulation, inhibiting photosynthesis to limit seedling growth. Considering the functional traits in heteroblastic foliage is necessary when assessing different leaf types of Pinus massoniana (Lamb.) seedlings, in particular those threats implicated in light, water, and temperature relations. Our results can be beneficial to guide the establishment of seedling management and afforestation measures.


2018 ◽  
Vol 10 (1) ◽  
pp. 33-37
Author(s):  
Md.Dulal SARKAR ◽  
Mohammad SHAHJAHAN ◽  
Khairul KABIR ◽  
Abu Yousuf SHIHAB ◽  
A.N.M. SAYEM

The present study was conducted to assess the morphological response of onion plants to different GA3 levels (0, 20, 40 and 60 ppm). The factor levels of GA3 were applied during transplanting by root soaking and foliar spray at 30 and 60 days after transplanting. The gibberellic acid had a great effect on increasing plant height (46.50 cm), shoot biomass (641.67 g m-2), bulb biomass (1125.00 g m-2) and also dry matter accumulation in onion plants under the effect of 60 ppm compared to control. Plants grown up without GA3 application were shorter than those grown with GA3 spray where the lowest plant height (34.67 cm) was remarked. The leaf number (11.43) was considerably increased when 60 ppm GA3 was used as the growth promoter factor in comparison to control. The plants attain minimum fresh biomass at harvesting time in the shoot (441.67 g m-2) and bulb (641.67 g m-2) grown in control plot. Considerably (41.63%) more dry shoot biomass accumulation was recorded in 60 ppm GA3 treated plants in comparison with the control at harvesting stages. Insignificant effect by all concentration of GA3 was found in bulb length, fresh root biomass and dry root biomass. Thus, the use of 60 ppm GA3 can be recommend for onion production due to the significantly increased of the fresh bulb biomass with about 42.96% over control.


2021 ◽  
Author(s):  
Cheyenne Lei ◽  
Michael Abraha ◽  
Jiquan Chen ◽  
Yahn-Jauh Su

Abstract Aims Long-term determination of root biomass production upon land use conversion to biofuel crops is rare. To assess land-use legacy influences on belowground biomass accumulation, we converted 22-year-old Conservation Reserve Program (CRP) grasslands and 50+-year-old agricultural (AGR) lands to corn (C), switchgrass (Sw) and restored prairie (Pr) biofuel crops. We maintained one CRP grassland as a reference (Ref). We hypothesized that land use history and crop type have significant effects on root density, with perennial crops on CRP grasslands having a higher root biomass productivity, while corn grown on former agricultural lands produce the lowest root biomass. Methods The ingrowth core method was used to determine in situ ingrowth root biomass, alongside measurements of aboveground net primary productivity (ANPP). Ancillary measurements, including air temperature, growing season length, and precipitation were used to examine their influences on root biomass production. Important Findings Root biomass productivity was the highest in unconverted CRP grassland (1716 g m -2 yr -1), and lowest in corn fields (526 g m -2 yr -1). All perennial sites converted from CRP and AGR lands had lower root biomass and ANPP in the first year of planting but peaked in 2011 for switchgrass and a year later for restored prairies. Ecosystem stability was higher in restored prairies (AGR-Pr: 4.3 ± 0.11; CRP-Pr: 4.1 ± 0.10), with all monocultures exhibiting a lower stability. Root biomass production was positively related to ANPP (R  2 = 0.40). Overall, attention should be given to root biomass accumulation in large-scale biofuel production as it is a major source of carbon sequestration.


1994 ◽  
Vol 142 (1) ◽  
pp. 145-152
Author(s):  
N Sato ◽  
X Wang ◽  
M A Greer

Abstract The standard method of studying hormone secretion in vitro is to make instantaneous changes in the concentration of stimulators in the medium. However, in vivo the extracellular concentration of such substances changes more gradually; secretion does not occur in square-wave bursts and agonists or antagonists transmitted through the bloodstream are diluted and diffused by plasma or tissue fluid to further decelerate the rate of change in concentration at the cell surface. We have therefore compared in GH4C1 cells the dynamics of changes in cytosolic Ca2+ concentration ([Ca2+]i) and prolactin (PRL) secretion in response to two very different secretagogues, thyrotrophin-releasing hormone (TRH) and depolarizing K+, using a square-wave or ramp exposure for 5 min. The dynamics of hormone secretion were analysed by column perifusion (2 × 106 cells/column). Ca2+ dynamics were monitored by dual excitation microfluorimetry from 20–30 optically isolated cells using the Ca2+ indicator, fura-2. With square-wave exposure, both TRH (0·1–100 nm) and K+ (10–50 mm) induced dose-dependent increases in [Ca2+]i and PRL secretion. Concentrations of TRH >1 nm caused a two-phase increase in [Ca2+]i with an initial high-amplitude first phase and a low-amplitude second phase. Depolarizing K+ induced a sharp increase in [Ca2+]i which peaked within 15 seconds, then declined gradually on a sloping plateau. Both TRH and K+ induced an acute dose-dependent PRL secretory burst peaking within 2·5 min with a subsequent rapid decline. With ramp exposure, high doses of TRH (final concentration 10–100 nm) triggered an acute rise in [Ca2+]i; however, the peaks were clearly lower than those induced by the maximum concentration reached given as a square-wave. TRH (0·1–100 nm) induced PRL secretion in a dose-dependent manner. Ramp depolarizing K+ induced dose-dependent parallel 'ramp' increases in [Ca2+]i concentration and PRL secretion without a 'burst' rise in either. These data suggest that a rise in [Ca2+]i plays a more critical role in K+-induced than in TRH-induced PRL secretion; intracellular transduction systems which do not involve [Ca2+]i appear more important for the latter. Journal of Endocrinology (1994) 142, 145–152


Sign in / Sign up

Export Citation Format

Share Document