scholarly journals The effect of UV-B radiation on the chlorophyll fluorescence parameters of the husked and the naked oat

2013 ◽  
Vol 52 (1-2) ◽  
pp. 149-152 ◽  
Author(s):  
Elżbieta Skórska

Naked oat variety of STH296 showed higher tolerance than traditional variety Bajka on short-term UV-B radiation (UV-B<sub>BE</sub>=1 1 kJ·m<sup>-2</sup>) on the stage of primary photosynthesis reaction recorded using chlorophyll fluorescence induction of the leaves.

2021 ◽  
Vol 1 (42) ◽  
pp. 80-85
Author(s):  
Yuriy Sudnik ◽  
◽  
Mahmud Abdelhamid ◽  
Valeriya Strokina ◽  
◽  
...  

Sorting tomatoes by controlling their maturation is an important direction that characterizes the quality and marketability of tomatoes. Therefore, reliable control of the maturation of tomatoes is an actual and practically significant task. Currently, there are known methods of such control (RGB), based on determining the color of tomatoes. These methods have disadvantages, for example, insufficient reliability of monitoring the maturation of tomatoes of various (especially not contrasting in color) varieties, complexity and expensive equipment. (Research purpose) The research purpose is in proposing a new method of rapid sorting of tomatoes based on the control of the minimum (initial) level (Fo) of their rapid phase of chlorophyll fluorescence induction. The time of a single Fo measurement is from 0.01 to 0.07 seconds. (Materials and methods) The article presents mathematical models and conducted experimental studies for the fast phase of chlorophyll fluorescence induction, which confirmed the functional relationship between the maturation of tomatoes and their minimum (initial) level (Fo) of the fast phase of chlorophyll fluorescence induction. Authors used widely distributed botanical varieties of tomatoes "Alcazar", "Lezginka", "Rozanchik" with five stages of maturation (green, brown, pink, light red and red), for each of which we determined the key indicators of chlorophyll fluorescence induction: maximum (Fm), minimum (Fo), variable (Fv) values, the ratio of indicators (Fv/Fm). (Results and discussion) Chlorophyll fluorescence can be used to assess the maturation of tomatoes. As tomatoes ripen, the values of chlorophyll fluorescence parameters, such as Fo, Fm, Fv, and Fv/Fm, decrease. The article presents models that allowed us to estimate the stage of maturation of tomatoes for all three varieties. (Conclusions) The model that used both parameters of chlorophyll fluorescence was the best for three varieties of tomatoes.


2014 ◽  
Vol 4 (1) ◽  
pp. 47-56 ◽  
Author(s):  
Luděk Sehnal ◽  
Peter Váczi ◽  
Miloš Barták

Trebouxia sp., a lichen symbiotic alga, was isolated from lichen Usnea antarctica collected at James Ross Island, Antarctica. After isolation, the alga was cultivated on Bold‘s Basal Medium (BBM-agar) with addition of nitrogen for 12 days. Growth of alga and its photosynthetic properties were studied in relation to increased concentration of CO2 (850±50 ppm) and two cultivation temperature (8 and 12°C). Physiological status of algae was evaluated by chlorophyll fluorescence parameters. Simultaneously, content of pigments and changes in biomass were evaluated during cultivation period. Evaluation of physiological state of Trebouxia sp. was carried out after the end of experiment. Results of chlorophyll fluorescence induction parameters and content of pigments showed that the highest efficiency of primary processes of photosynthesis was found at the treatment with elevated concentration of CO2 and temperature 12°C. In this treatment, potential quantum yield of photochemical processes in photosystem II (FV/FM) was 0.44 and content of Chl a was 5.14 µg ml-1. In contrast, the lowest efficiency of primary processes was found at the treatment with addition of CO2 and temperature 8°C, where value of FV/FM reached 0.37 and content of Chl a was 3.71 µg ml-1.


Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 508 ◽  
Author(s):  
Carmen Arena ◽  
Stefano Conti ◽  
Silvana Francesca ◽  
Giuseppe Melchionna ◽  
Josef Hájek ◽  
...  

High temperatures represent a limitation for growth and development of many crop species. Several studies have demonstrated that the yield reduction of tomato under high temperatures and drought is mainly due to a photosynthetic decline. In this paper, a set of 15 tomato genotypes were screened for tolerance to elevated temperatures by cultivating plants under plastic walk-in tunnels. To assess the potential tolerance of tomato genotypes to high temperatures, measurements of chlorophyll fluorescence, pigments content and leaf functional traits have been carried out together with the evaluation of the final yields. Based on the greenhouse trials, a group of eight putative heat-sensitive and heat-tolerant tomato genotypes was selected for laboratory experiments aimed at investigating the effects of short-term high temperatures treatments in controlled conditions. The chlorophyll fluorescence induction kinetics were recorded on detached leaves treated for 60 min at 35 °C or at 45 °C. The last treatment significantly affected the photosystem II (PSII) photochemical efficiency (namely maximum PSII quantum efficiency, Fv/Fm, and quantum yield of PSII electron transport, ΦPSII) and the non-photochemical quenching (NPQ) in the majority of genotypes. The short-term heat shock treatments also led to significant differences in the shape of the slow Kautsky kinetics and its significant time points (chlorophyll fluorescence levels minimum O, peak P, semi-steady state S, maximum M, terminal steady state T) compared to the control, demonstrating heat shock-induced changes in PSII functionality. Genotypes potentially tolerant to high temperatures have been identified. Our findings support the idea that chlorophyll fluorescence parameters (i.e., ΦPSII or NPQ) and some leaf functional traits may be used as a tool to detect high temperatures-tolerant tomato cultivars.


2013 ◽  
Vol 38 (6) ◽  
pp. 1062-1070
Author(s):  
Ye-Chun LIN ◽  
Zhao-Hai ZENG ◽  
Chang-Zhong REN ◽  
Zhi-Jian LI ◽  
Lai-Chun GUO ◽  
...  

2015 ◽  
Vol 59 (1) ◽  
pp. 187-192 ◽  
Author(s):  
J. Z. Li ◽  
Y. P. Chen ◽  
K. Q. Teng ◽  
L. Z. Qin ◽  
Y. X. Du ◽  
...  

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