perennial plants
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2021 ◽  
Author(s):  
Lilia Chisnicean ◽  
◽  
Elvira Gille ◽  

Sideritis of the Genus Sideritis - introducers of the spicy aromatic collection. Sideritis is a genus of annual and perennial plants of the family Lamiaceae. The plant has a pleasant aroma and many medic-inal benefits. Foliage and inflorescences are sold as unusual tea in all Mediterranean countries. Reproduc-tion of the plant was carried out by seedlings, which were obtained from seeds, or vegetative using cut-tings from annual shoots. As a result of introduction studies, we managed to propagate and introduce in our collection two of its subspecies - Sideritis scardica and S.taurica, as medicinal and spicy-aromatic, drought-tolerant plants.


2021 ◽  
Author(s):  
Abraam Zakhary ◽  
Aashika Nagarajan ◽  
Charlotte Ngo ◽  
Marwa Saidajan ◽  
Supreet Babbar ◽  
...  

Abstract Purpose. The Oxidative Stress Theory of Aging (OSTA) states that accumulation of oxidative damage is a major contributor to aging; however, until now, no studies have examined whether perennial plants exhibit cellular mechanisms to better protect themselves against oxidative damage than annual plants, nor how these mechanisms may have evolved. Methods. We undertook three approaches to evaluate the capacity for annual and perennial plants to resist oxidative damage. The first approach involved using an electrolyte leakage assay to assess the rate of cellular damage in leaves exposed to exogenous H 2 O 2 . The second approach involved determining the concentration of exogenous H 2 O 2 required to maximize germination rates, which provides insight about the antioxidant levels in seeds. The third approach involved assessing the susceptibility of chlorophyll a and chlorophyll b to exogenous H 2 O 2 and determining chlorophyll a/b ratios. We also conducted an ancestral state reconstruction of life history strategies in order to interpret our results in an evolutionary context. Results. Leaves from deciduous and evergreen perennials showed a lower rate of cellular damage than leaves from annuals when exposed to exogenous H 2 O 2 . Seeds from deciduous perennials—but not biennials or evergreen perennials—required a higher H 2 O 2 concentration to maximize germination rate compared to seeds from annuals, suggesting that seeds from deciduous perennials have higher antioxidant levels. Although chlorophyll b was found to be more susceptible to damage from exogenous H 2 O 2 , chlorophyll a/b ratios did not differ among life history strategies. Ancestral state reconstruction revealed that the ancestral plant was most likely an evergreen perennial. Conclusion. Our results showcase that resistance to oxidative stress is necessary for perennial plants to survive over multiple years. The mechanisms responsible for the increased tolerance of perennial species to oxidative stress has not been fully elucidated by this study, but it does not involve changes to chlorophyll a/b ratios, as such changes could disrupt photosynthesis. The developmental onset of these protective mechanisms was delayed in evergreen perennials compared to deciduous perennials, perhaps because the ancestral evergreens were primarily focused on rapid colonization of the terrestrial environment, which requires faster germination rates induced by higher H 2 O 2 levels.


2021 ◽  
Vol 5 ◽  
pp. 100-107
Author(s):  
Daniela Pilarska ◽  
Diana Gadzhalova ◽  
Danail Takov

Fourteen hundred and sixty three larvae of 10 lepidopteran species collected from trees and bushes in the spring and summer of 2017, 2018 and 2019 from 5 localities in Northwest and South Bulgaria were investigated for presence of microsporidian and fungal pathogens. Also, 77 grasshopper individuals of Poecilimon thoracicus (Orthoptera, Tettiigoniidae) collected from various shrubs and perennial plants in the spring and summer of 2017 were examined. Conducted microscopic analyses showed the presence of microsporidian infection caused by Endoreticulatis poecilimonae in P. thoracicus and fungal infection in the larvae of mottled umber, Erannis defoliaria caused by Entomophaga auliciae. The studies showed that the average infection rate with the microsporidium E. poecilimonae was 57.1%. The prevalence of the fungus Entomophaga auliciae was 100% during the observed epizootic. E. auliciae is an efficient fungal pathogen which causes strong epizootics and can be used as classical or augmentation biological agent.


2021 ◽  
Vol 38 ◽  
pp. 00112
Author(s):  
Varvara Semenova

This research work details analysis of the coenopopulation structure of 13 plants of various species in Yakutia and compares them with the characteristic spectra types of their species. The structure of plant coenopopulations was investigated from 2003 to 2019 in Central Yakutia. The left-sided and centered ontogenetic spectra are found in perennial plants with simple ontogenesis and shallow rejuvenation which were studied. The left-sided spectrum is the basic structure of these coenopopulations. The centered ontogenetic spectrum is largely found in unfavorable growing conditions under the impact of grazing and trampling by cattle and horses. This rule applies to the CP structure of Veronica incana which is an evergreen chamaephyte and for which the seasonal anthropogenic load contributes to the mechanical vegetative reproduction of its species, resulting in stable left-sided CP spectra. The ontogenetic spectra of the studied plants coincide with the characteristic spectra of the species and are considered stable.


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