scholarly journals Influence of nitrogen deficiency on photosynthesis and chloroplast ultrastructure of pepper plants (Research Note)

2001 ◽  
Vol 10 (1) ◽  
pp. 59-64 ◽  
Author(s):  
S. DONCHEVA ◽  
V. VASSILEVA ◽  
G. IGNATOV

Pepper plants (Capsicum annuum L. cv. Zlaten Medal) were grown on nutrient solution without nitrogen, and photosynthetic response of plants was examined by determination of leaf CO2 fixation and chlorophyll and carotenoid contents. The absence of nitrogen in the medium resulted in a decrease of the leaf area and of plant biomass accumulation, and in an increase of the root-shoot dry weight ratio. The photosynthetic activity and chlorophyll and carotenoid contents decreased significantly under nitrogen deprivation. Examination of nitrogen deficient leaves by transmission electron microscopy showed dramatic changes in chloroplast ultrastructure. The proportion of starch granules and plastoglobules in the stroma matrix was increased and internal membrane system was greatly reduced. It seems that nitrogen plays an important role in the formation of chloroplast structure and hence to the photosynthetic intensity and productivity of pepper plants.

2019 ◽  
Vol 46 (No. 2) ◽  
pp. 98-106 ◽  
Author(s):  
Filippos Bantis ◽  
Kalliopi Radoglou

The effect of light-emitting diodes (LED) with broad radiation spectra on developmental, physiological, and phytochemical characteristics of Greek sage (Salvia fruticosa L.) seedlings was assessed. Fluorescent (FL – control) tubes and four LED lights [AP67 (moderate blue, red and far-red), L20AP67 (moderate blue, red and far-red, high green), AP673L (moderate blue, high red) and NS1 (high blue and green, low red, high red : far-red, 1% ultraviolet)] were used in a growth chamber. Seedlings grown under FL, L20AP67 and AP673L exhibited the best morphological and developmental characteristics. FL led to inferior root biomass formation compared to all LEDs. AP67 promoted greater root-to-shoot dry weight ratio and dry-to-fresh overground and root weight ratios, but induced the least morphological and developmental characteristics. NS1 performed well regarding the root biomass production. Total phenolic content and the root growth capacity were not significantly affected. The present study demonstrates that L20AP67 and AP673L LEDs performed equally to FL light regarding the developmental characteristics. AP67 and NS1 may have the potential to be used for compact seedling production.


2017 ◽  
Vol 9 (1) ◽  
pp. 582-586
Author(s):  
R. J. Patel ◽  
T. R. Ahlawat ◽  
A. I. Patel ◽  
J. J. Amarcholi ◽  
B. B. Patel ◽  
...  

An experiment was carried out at Navsari Agricultural University, Navsari during 2014 to evaluate the effect of pre-sowing treatments on survival percentage and growth of mango rootstocks. Mango stones were soaked in aqueous solutions of GA3 (100 and 200 ppm), Beejamruth (2 % and 3 %) and Thiourea (1 % and 2 %) for 12 and 24 hours. The trial was evaluated in Completely Randomized Design based on factorial concept and the treatments were replicated thrice. Imposition of treatments led to significant differences at 5 % level of significance for all parameters chosen in this study. Mango stones when treated with Thiourea at 1 % had the maximum shoot length (49.93 cm), root length (34.38 cm), shoot dry weight (21.08 g) and total dry weight (26.36 g). The highest number of lateral roots (10.90) and survival percentage (64.17) was observed in mango stones dipped in 100 ppm GA3. Between the two soaking duration, soaking mango stones for 24 hours recorded higher values for shoot length (45.03 cm), root length (32.79 cm), number of lateral roots (9.83), survival percentage (62.72), shoot root fresh weight ratio (4.30), shoot dry weight (21.33 g), total dry weight (26.28 g) and shoot root dry weight ratio (4.32). Thus, survival percentage and growth of mango rootstocks can be substantially improved by soaking mango stones in aqueous solutions of 100 ppm GA3 or Thiourea at 1 % for 24 hours before sowing.


Weed Science ◽  
1993 ◽  
Vol 41 (3) ◽  
pp. 335-340 ◽  
Author(s):  
Frank S. Rossi ◽  
Joseph M. Di Tomaso ◽  
Joseph C. Neal

Investigations of smooth crabgrass growth and fenoxaprop-ethyl retention, foliar penetration, translocation, and metabolism were conducted at various soil moisture levels using a polyethylene glycol (PEG) semipermeable membrane system. The activity of fenoxapropethyl was significantly reduced at higher levels of moisture stress and this antagonistic effect was greater with increased duration of water deficit following herbicide application. Fenoxaprop-ethyl spray retention decreased linearly (23% total reduction) as soil matric potential (Ψm) decreased from −0.01 to −0.1 MPa. Foliar penetration and translocation of14C-fenoxaprop-ethyl applied on the third true leaf were not affected by level or duration of moisture stress. Only 2% of the absorbed radioactivity was translocated out of the treated leaf for each moisture stress level and duration. As the soil Ψm decreased (−0.01 to −1.0 MPa) the relative levels of fenoxaprop-ethyl increased by 76 and 65% after a 48- and 96-h postapplication moisture stress period, respectively. In contrast, fenoxaprop acid decreased by 59 and 44% after 48 and 96 h of moisture stress, respectively. The relative level of fenoxaprop acid was linearly correlated to the antagonistic effect on shoot dry weight. These results suggest that decreased spray retention and, particularly, alterations in fenoxaprop-ethyl metabolism contribute to reduced fenoxaprop-ethyl activity observed in moisture-stressed smooth crabgrass.


2006 ◽  
Vol 54 (4) ◽  
pp. 469-485 ◽  
Author(s):  
G. Singh ◽  
D. Wright

Effects of one pre-emergence herbicide (terbutryn/terbuthylazine) and one post-emergence herbicide (bentazone) along with unweeded and hand-weeded controls on weeds and on the nodulation, nitrogenase activity, nitrogen content, growth and yield of pea (Pisum sativum) were studied. Terbutryn/terbuthylazine was applied pre-emergence @ 1.40, 2.80 and 5.60 kg/hawhereas bentazone was sprayed 6 weeks after sowing @ 1.44, 2.88 and 5.76 kg/h. Terbutryn/terbuthylazine controlled all the weeds very effectively, whereas bentazone did not control some weeds such as Polygonum aviculare, Poa annua and Elymus repens. The herbicides decreased the number of nodules, the dry weight of nodules, the nitrogenase activity, the shoot dry weight, the nitrogen content in the straw and seeds, and the seed yield of peas, the effects generally being higher at higher rates of application. The adverse effects of herbicides on these parameters might be due to their effects on plant growth, as both the herbicides are known to adversely affect photosynthesis. Nitrogenase activity did not correlate well with plant-N content or shoot dry weight. However, there was a strong relationship between plant biomass and plant-N content, which suggests that researchers can rely on these parameters for studying the effects of treatments on nitrogen fixation, rather than measuring nitrogenase activity.


1992 ◽  
Vol 7 (1) ◽  
pp. 25-29 ◽  
Author(s):  
M. L. Cherry ◽  
D. T. Lester

Abstract Genetic variation in several traits of Alaska-cedar (Chamaecyparis nootkatensis) was measured in progeny from seven coastal B.C. provenances, each represented by three open-pollinated families. The common-garden nursery trial also included one provenance of Port-Orford cedar (Chamaecyparis lawsoniana). Growth traits and frost hardiness were measured at the end of the first growing season, and morphological traits after the second year. Provenances varied in percentage germination, shoot dry weight, shoot to root dry weight ratio, number of lateral branches per stem, and cold injury to a minimum temperature of -20°C in December. Families differed in height, root collar diameter, and in the number of nodes of primary foliage. Port-Orford cedar exhibited much greater height, stem caliper, and dry weight than any Alaska-cedar provenance, but was more susceptible to frost damage. West. J. Appl. For. 7(1):25-29.


HortScience ◽  
2018 ◽  
Vol 53 (6) ◽  
pp. 795-798 ◽  
Author(s):  
Chang-Tsern Chen ◽  
Ching-Lung Lee ◽  
Der-Ming Yeh

Growth and photosynthetic parameters were measured in Eustoma grandiflorum (Raf.) Shinn. ‘Umihonoka’ grown hydroponically under nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), or magnesium (Mg) deficiency in 1/2 strength of modified Johnson’s solution. Plant height, node number, and leaf area were all reduced under N, P, K, and Ca deficiencies but not under Mg deficiency as compared with plants grown in the complete nutrient solution. Shoot and root dry weight were reduced in the N-, P-, K-, and Ca-deficient treatments, whereas root but not shoot dry weight was lowered by Mg-deficient treatment. Shoot-to-root dry weight ratio decreased under N and P deficiencies, increased under K and Mg deficiency, but was not altered under Ca deficiency. Decreased net photosynthetic rate (Pn) of N-, P-, and K-deficient leaves was all related to lower stomatal conductance (gS), whereas N-deficient leaves also accompanied by a higher intercellular carbon dioxide concentration (Ci). The Mg-deficient treatment did not alter chlorophyll fluorescence Fv/Fm, maximal fluorescence (Fm), or minimal fluorescence (Fo). Decreased Fv/Fm of N-, P-, K-, and Ca-deficient leaves was all related to lower Fm, whereas N- and P-deficient leaves also accompanied by lower Fo. A key was developed for the identification of N, P, K, Ca, and Mg deficiency symptoms.


1992 ◽  
Vol 10 (4) ◽  
pp. 232-235
Author(s):  
David R. Brown ◽  
D. Joseph Eakes ◽  
Bridget K. Behe ◽  
Charles H. Gilliam

Abstract Moisture stress was compared to B-nine (daminozide) as a method of height control for annual bedding plant transplants. Three plant species, ‘Big Boy’ tomato, ‘California Wonder’ pepper and ‘Janie Gold’ marigold, were grown in 132 cm3 (8.05 in3) cell packs containing one of 2 commercial media, Fafard #3 or Pro-Mix BX. Treatments included moisture stress (MS), 2 concentrations of B-nine (2500 ppm applied twice and 5000 ppm once), and an untreated control. Method of height control and medium type had an interactive influence on height for each of the 3 species. Moisture stress tomato and marigold were shorter in the Fafard #3 medium compared to those in the Pro-Mix BX medium. Regardless of medium, MS tomato and marigold transplants were shorter or similar in size to the most effective B-nine treatment, 2500 ppm applied twice. Moisture stress and the B-nine treatments for pepper plants grown in the Fafard #3 medium reduced plant height similarly compared to the controls. However, when pepper plants were grown in the Pro-Mix BX medium, only B-nine treatments reduced plant height compared to the controls. Treatments producing short plants did not reduce node number, hence plants appeared fuller than treatments with tall plants. Shoot dry weights for MS tomato and marigold were less than those of plants receiving the other height control treatments, regardless of medium type. Plants of all 3 species grown in the Fafard #3 medium had less shoot dry weight than Pro-Mix BX plants across the 4 height control treatments.


1996 ◽  
Vol 14 (3) ◽  
pp. 105-110 ◽  
Author(s):  
Edward F. Gilman ◽  
Thomas H. Yeager ◽  
Diane Weigle

Abstract Dwarf burford holly (Ilex cornuta ‘Burfordii Nana’) fertilized with 22.1 g N/container/yr of nitrogen during production in the nursery generated more new shoot weight but less root weight after transplanting to a landscape than those receiving 14.8 g N/container/yr. Slicing the root ball at planting, compared to not slicing, resulted in comparable regenerated root weight but reduced new shoot number, new shoot dry weight and new shoot:regenerated root dry weight ratio when irrigation was not applied daily after transplanting. Although irrigation frequency did not impact total weight of regenerated roots into landscape soil, more roots grew from the bottom half of the root ball when plants were irrigated periodically after planting than when plants received daily irrigation. Plants irrigated other than daily produced fewer shoots and less shoot weight than those receiving irrigation daily after transplanting. When plants were without irrigation for 4 or 6 days in the first week after transplanting, those planted without the nursery container on the root ball were more stressed (more negative xylem potential) than those planted with the container still on the root ball. However, two weeks later, plants without the nursery container were less stressed due to root growth into landscape soil.


2020 ◽  
Vol 7 (3) ◽  
pp. 1111-1119
Author(s):  
Julio Cezar Tannure Faria ◽  
Marcos Vinícius Winckler Caldeira ◽  
William Macedo Delarmelina ◽  
Erick Martins Nieri ◽  
Denys Santana Souza ◽  
...  

In the production of forest seedlings one of the main factors to be analyzed is the formulation of the substrate that meets the needs of the plants that will be produced. For this, the choice of substrate must consider the physical characteristics of the material, its chemical composition, as well as its availability, quality, easy handling and cost. This study aimed to investigate the potential of sewage sludge and rice husk for the production of seedlings of Mimosa setosa. The experiment was conducted in structures of a forest nursery, localized in the municipality of Alegre-ES, in 110 cm³ tubes arranged in a completely randomized design constituted by ten treatments with four replications of 54 seedlings per plot. The treatments were formulated using sewage sludge, raw rice husks and carbonized rice husk. At five months after sowing we measured plant height, root collar diameter, height/diameter ratio, shoot dry weight, root dry weight, total dry matter, shoot to root dry weight ratio and Dickson Quality Index. The substrates formulated with carbonized rice husk promoted the best results for all morphological characteristics analyzed. The multivariate analysis showed higher correlation of treatments with carbonized rice husk (T6, T7, T8 and T9) regarding height, root collar diameter, root dry weight, shoot dry weight and total dry matter. For the production of Mimosa setosa seedlings the best responses resulted from the substrate formulated with 60% sewage sludge + 40% carbonized rice husk.


Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1529
Author(s):  
Ramón Gisbert-Mullor ◽  
Nuria Pascual-Seva ◽  
María Amparo Martínez-Gimeno ◽  
Lidia López-Serrano ◽  
Eduardo Badal Marín ◽  
...  

In this study, hybrid pepper rootstock NIBER® is tested for its ability to overcome water stress situations under soil conditions. The impact of deficit irrigation (DI) on yield and fruit quality, irrigation water use efficiency is evaluated, and consequently, the agronomic impact of employing water-stress tolerant rootstock is compared to ungrafted pepper plants. For this purpose, plants of the California-type sweet pepper ‘Maestral F1’ grafted onto NIBER® underwent a sustained DI regime during seasons 2018 and 2019 and were compared to their respective controls. Plants were drip-fertirrigated, and volumetric soil water content was continuously monitored by capacitance sensors. Gas exchange and leaf water potential measurements were taken early in the morning and midday 58, 79, and 114 days after transplanting. Plant and fruit dry biomass, marketable quality, blossom-end rot incidence and harvest index were also determined. For consecutive years, our results confirmed that grafting a pepper cultivar onto an appropriate rootstock (NIBER® in this case) as part of a DI strategy can overcome the negative effects of sustained water stress conditions. The plant biomass production and fruit yields of grafted plants were less affected by DI due to less sensitivity to water stress. This can be attributed to a less marked reduction in shoot dry weight in the grafted plants, which allowed greater whole photosynthesis by maintaining sink activity compared to ungrafted plants.


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