The Effects of Herbivory by a Mite, Aculus hyperici, and Nutrient Deficiency on Growth in Hypericum Species

1995 ◽  
Vol 43 (3) ◽  
pp. 305 ◽  
Author(s):  
AJ Willis ◽  
JE Ash ◽  
RH Groves
Keyword(s):  
Biological Control ◽  
Plant Growth ◽  
Hypericum Perforatum ◽  
Nutrient Deficiency ◽  
Combined Effects ◽  
Nutrient Deficiencies ◽  
Hypericum Perforatum L ◽  
Hypericum Species

The combined effects of herbivory by a mite, Aculus hyperici Liro, and a deficiency of nutrients on plant growth were measured for Hypericum perforatum L. and H. gramineum J.Forst. grown in a glasshouse. The results are discussed in relation to the biological control of H. perforatum, an introduced weed in southern Australia, relative to growth of its indigenous congener, H. gramineum. Growth of both species was reduced when infested with the mite, although the growth of H. perforatum was reduced by more than that of H. gramineum. Nutrient deficiencies also reduced growth of both species, especially of roots. Imposition of nutrient deficiency on mite-infested plants caused multiplicative reductions in plant growth equivalent to the product of the proportional reductions caused by either herbivory or nutrient deficiency alone.

scholarly journals A Study of Factors Influencing Plant Growth by WSN Approach and Plant Nutrient Deficiency Classification in Tomato Using SVM

2021 ◽  
Vol 23 (06) ◽  
pp. 36-46
Author(s):  
Vrunda Kusanur ◽  
◽  
Veena S Chakravarthi ◽  
Keyword(s):  
Machine Learning ◽  
Plant Growth ◽  
Nutrient Deficiency ◽  
Learning Model ◽  
Plant Nutrients ◽  
Polynomial Kernel ◽  
Second Phase ◽  
Nutrient Deficiencies ◽  
Deficiency Symptoms ◽  
Machine Learning Model

Soil temperature and humidity straight away influence plant growth and the availability of plant nutrients. In this work, we carried out experiments to identify the relationship between climatic parameters and plant nutrients. When the relative humidity was very high, deficiency symptoms were shown on plant leaves and fruits. But, recognizing and managing these plant nutrients manually would become difficult. However, no much research has been done in this field. The main objective of this research was to propose a machine learning model to manage nutrient deficiencies in the plant. There were two main phases in the proposed research. In the first phase, the humidity, temperature, and soil moisture in the greenhouse environment were collected using WSN and the influence of these parameters on the growth of plants was studied. During experimentation, it was investigated that the transpiration rate decreased significantly and the macronutrient contents in the plant leave decreased when the humidity was 95%. In the second phase, a machine learning model was developed to identify and classify nutrient deficiency symptoms in a tomato plant. A total of 880 images were collected from Bingo images to form a dataset. Among all these images, 80% (704 images) of the dataset were used to train the machine learning model and 20% (176 images) of the dataset were used for testing the model performance. In this study, we selected K-means Clustering for key points detection and SVM for classification and prediction of nutrient stress in the plant. SVM using linear kernel performed better with the accuracy rates of 89.77 % as compared to SVM using a polynomial kernel.

scholarly journals Decoupling of Plant Growth and Accumulation of Biologically Active Compounds in Leaves, Roots, and Root Exudates of Hypericum perforatum L. by the Combination of Jasmonate and Far-Red Lighting

Biomolecules ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1283 ◽  
Author(s):  
Martina Paponov ◽  
Manya Antonyan ◽  
Rune Slimestad ◽  
Ivan A. Paponov
Keyword(s):  
Secondary Metabolites ◽  
Plant Growth ◽  
Root Exudates ◽  
Hypericum Perforatum ◽  
Secondary Compounds ◽  
Biologically Active ◽  
Starch Accumulation ◽  
Combined Application ◽  
Hypericum Perforatum L ◽  
Spraying Plants

The plant hormone jasmonic acid (JA) fine tunes the growth–defense dilemma by inhibiting plant growth and stimulating the accumulation of secondary compounds. We investigated the interactions between JA and phytochrome B signaling on growth and the accumulation of selected secondary metabolites in Hypericum perforatum L., a medically important plant, by spraying plants with methyl jasmonate (MeJA) and by adding far-red (FR) lighting. MeJA inhibited plant growth, decreased fructose concentration, and enhanced the accumulation of most secondary metabolites. FR enhanced plant growth and starch accumulation and did not decrease the accumulation of most secondary metabolites. MeJA and FR acted mostly independently with no observable interactions on plant growth or secondary metabolite levels. The accumulation of different compounds (e.g., hypericin, flavonols, flavan-3-ols, and phenolic acid) in shoots, roots, and root exudates showed different responses to the two treatments. These findings indicate that the relationship between growth and secondary compound accumulation is specific and depends on the classes of compounds and/or their organ location. The combined application of MeJA and FR enhanced the accumulation of most secondary compounds without compromising plant growth. Thus, the negative correlations between biomass and the content of secondary compounds predicted by the growth-defense dilemma were overcome.

The spectral properties of Hypericum perforatum leaves: the implications for its photoactivated defences

1990 ◽  
Vol 68 (5) ◽  
pp. 1166-1170 ◽  
Author(s):  
Paul G. Fields ◽  
John T. Arnason ◽  
R. Gary Fulcher
Keyword(s):  
Visible Light ◽  
Ultraviolet Light ◽  
Spectral Properties ◽  
Hypericum Perforatum ◽  
Herbarium Specimens ◽  
Artificial Diets ◽  
Hypericum Perforatum L ◽  
Hypericum Species

Unlike most other plant-derived phototoxins that are activated by ultraviolet light, hypericin from Hypericum species causes photoactivated damage by absorbing visible light (550–610 nm, maximum at 585 nm). Clear glands from Hypericum perforatum L. transmitted 66%, veins, 6% and the mesophyll, 1% of the light at 585 nm. When the total area of the various structures was taken into account, leaves transmitted approximately 2% of the light in the photoactive range of hypericin. Other studies have shown that this intensity of light is sufficient to cause light-induced mortality in insects fed on artificial diets containing hypericin. Having a phototoxin that is activated by the same wavelengths of light that are reflected and transmitted by plants may prevent insects from avoiding phototoxicity by simply hiding under or rolling leaves. However, a survey of herbarium specimens indicated that clear glands were not an obligate component of the photoactivated defences of Hypericum species.

scholarly journals Genetic diversity and relationships among Hypericum L. species by ISSR Markers: A high value medicinal plant from Northern of Iran

Caryologia ◽  
2021 ◽  
Vol 74 (1) ◽  
pp. 97-107
Author(s):  
Shuyan Ma ◽  
Majid Khayatnezhad ◽  
Amir Abbas Minaeifar
Keyword(s):  
Hypericum Perforatum ◽  
High Capacity ◽  
Molecular Data ◽  
Issr Markers ◽  
Herbal Preparations ◽  
Inter Simple Sequence Repeats ◽  
Hypericum Perforatum L ◽  
Simple Sequence ◽  
Hypericum Species ◽  
Issr Primers

Hypericum L. species are generally known locally in Iran with the names “Hofariqun” which Ebn Sina (or Bo Ali Sina) called it. Plants of the genus Hypericum have traditionally been used as medicinal plants in various parts of the world. Hypericum perforatum L. is the source to one of the most manufactured and used herbal preparations in recent years, especially as a mild antidepressant. Therefore, due to the importance of these plant species, we performed a molecular data for this species. For this study, we used 175 randomly collected plants from 17 species in 9 provinces. Amplification of genomic DNA using 10 primers produced 141 bands, of which 127 were polymorphic (95.78%). The obtained high average PIC and MI values revealed high capacity of ISSR primers to detect polymorphic loci among Hypericum species. The genetic similarities of 17 collections were estimated from 0.617 to 0.911. According to Inter-Simple sequence repeats (ISSR) markers analysis, H. androsaemum and H. hirtellum had the lowest similarity and the species of H. perforaturm and H. triquetrifolium had the highest similarity. The aims of present study are: 1) can ISSR markers identify Hypericum species, 2) what is the genetic structure of these taxa in Iran, and 3) to investigate the species inter-relationship? The present study revealed that ISSR markers can identify the species. 

scholarly journals 161 Using a Controlled Water Table Irrigation for Class Demonstrations of Plant Growth

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 470A-470
Author(s):  
J.W. Buxton ◽  
T. Phillips
Keyword(s):  
Plant Growth ◽  
Water Table ◽  
Nutrient Solution ◽  
Irrigation System ◽  
Nutrient Deficiency ◽  
Zn Deficiency ◽  
Nutrient Deficiencies ◽  
Poor Growth ◽  
Growing Media ◽  
Set Up

In class demonstrations, it is almost impossible to maintain the same water: air ratio in growing media. If some treatments result in greater plant growth than others, treatment effects on plant growth are often confounded with the effect of water: air ratio in the growing media. In a laboratory demonstration of nutrient deficiencies symptoms in plants, a controlled water table irrigation system maintained a constant water: air ratio in the growing media regardless of the nutrient deficiency affect on plant growth. The modified capillary mat irrigation system consists of one mat edge extending over the edge of the bench into a narrow trough on the side of the bench. The nutrient solution level in the trough is controlled by a liquid level controller, so it is at a fixed distance below the bench surface. The nutrient solution is drawn upward by capillarity to the bench surface and then moves by capillarity over the bench. The system automatically maintains a constant air: water ratio in the growing media. A standard Hogland solution was modified to demonstrate deficiencies in N, P, K, Mg, Ca, Cu, Fe, and Zn on corn, squash, radish, soybeans, and marigold. Seeds were germinated and grown to maturity in either a 10- or 15-cm pot. Students set up the demonstration, were provided instruction in preparing solutions, regularly observed plant growth, and answered questions at the end of the study about differences in plant growth observed. However, possibly because low concentrations of some minor elements in the capillary mat, Zn deficiency was not observed and other elements, although resulting in poor growth compared to the control, did not show severe deficiency symptoms.

Interactions between Plant Competition and Herbivory on the Growth of Hypericum Species: a Comparison of Glasshouse and Field Results

1998 ◽  
Vol 46 (6) ◽  
pp. 707 ◽  
Author(s):  
Anthony J. Willis ◽  
Richard H. Groves ◽  
Julian E. Ash
Keyword(s):  
Biological Control ◽  
Field Experiment ◽  
Native Species ◽  
Field Experiments ◽  
Plant Competition ◽  
Plant Productivity ◽  
Combined Effects ◽  
The Impact ◽  
Hypericum Species

The combined effects of interspecific plant competition and herbivory by a mite, Aculus hyperici Liro, on the growth of two Hypericum species were compared in separate glasshouse and field experiments. The impact of mites on H. perforatum L. was slightly greater than their effect on H. gramineum Forst. In both the glasshouse and the field, competition affected Hypericum growth more adversely than herbivory. There was little evidence that combinations of competition and herbivory caused complex synergistic reductions in plant productivity. In combination, herbivory and competition caused proportional reductions in growth, approximately equivalent to the product of the proportional growth under competition and herbivory individually. Broadly similar results were achieved in both the glasshouse and the field experiment. The results are discussed in relation to the biological control of H. perforatum by A. hyperici, and the impact of this arthropod on the growth of H. gramineum, a non-target native species.

scholarly journals Differential phenolic accumulation in two Hypericum species in response to inoculation with Diploceras hypericinum and Pseudomonasputida

2014 ◽  
Vol 50 (No. 3) ◽  
pp. 119-128 ◽  
Author(s):  
C. Cirak ◽  
J. Radusiene ◽  
H.M. Aksoy ◽  
R. Mackinaite ◽  
Z. Stanius ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Hypericum Perforatum ◽  
Plant Defence ◽  
Defence Response ◽  
Phenolic Constituents ◽  
Plant Growth Promoting ◽  
Hypericum Perforatum L ◽  
Growth Promoting ◽  
Hypericum Species ◽  
Plant Defence Response

The genus Hypericum L. (St. John’s-wort, Hypericaceae) has received scientific interest in recent years, because it is a source of a variety of bioactive compounds including the phenolics. We determine whether the typical phenolic constituents of Hypericum plants, namely chlorogenic acid, rutin, hyperoside, isoquercetine, quercitrine, and quercetine, may be implicated as part of an inducible plant defence response in two St. John’s-wortspecies, Hypericum perforatum L. and Hypericum triquetrifolium Turra. To achieve this objective, greenhouse-grown plantlets were inoculated with the fungal pathogen Diploceras hypericinum and the plant growth promoting bacterium Pseudonomas putida. Phenolic compounds levels of the Hypericum plantlets increased significantly in response to inoculation with both organisms. So far, little effort has been dedicated to investigate whether phenolic compounds are inducible by pathogen/herbivore attack or if they could play a role in plant defence. Results from the study indicate that the phenolic compounds investigated could be involved in the plant defence system and implicated as part of an inducible plant defence response in both St. John’s Wort species.

The hyp-1 gene is not a limiting factor for hypericin biosynthesis in the genus Hypericum

2011 ◽  
Vol 38 (1) ◽  
pp. 35 ◽  
Author(s):  
Ján Košuth ◽  
Andrija Smelcerovic ◽  
Thomas Borsch ◽  
Sebastian Zuehlke ◽  
Katja Karppinen ◽  
...  
Keyword(s):  
Candidate Gene ◽  
Hypericum Perforatum ◽  
Limiting Factor ◽  
Gene Transcript ◽  
Coding Sequences ◽  
Key Enzyme ◽  
Hypericum Perforatum L ◽  
Hypericum Species ◽  
Dark Glands

Biosynthesis of the hypericins that accumulate in the dark glands of some members of the genus Hypericum is poorly understood. The gene named hyp-1, isolated from Hypericum perforatum L. has been proposed as playing an important role in the final steps of hypericin biosynthesis. To study the role of this candidate gene in relation to the production of hypericins, the expression of this gene was studied in 15 Hypericum species with varying ability to synthesise hypericin. While the accumulation of hypericins and emodin, an intermediate in the respective pathway, was associated with the dark glands in the hypericin-producing species, the hyp-1 gene was expressed in all studied species regardless of whether hypericins and emodin were detected in the plants. The coding sequences of hyp-1 cDNA were isolated from all species and showed more than 86% similarity to each other. Although, in general, an increased level of the hyp-1 gene transcript was detected in hypericin-producing species, several of the hypericin-lacking species expressed comparable levels as well. Our results question the role of the hyp-1 gene product as a key enzyme responsible for biosynthesis of hypericins in the genus Hypericum. The function of the hyp-1 gene may not be restricted to hypericin biosynthesis only, or some additional factors are necessary for completion of hypericin biosynthesis.

Sign in / Sign up

Export Citation Format

Share Document