Quantification of additive response and stationarity of frost hardiness by photoperiod and temperature in Scots pine

2003 ◽  
Vol 33 (9) ◽  
pp. 1772-1784 ◽  
Author(s):  
Gang Zhang ◽  
Aija Ryyppö ◽  
Elina Vapaavuori ◽  
Tapani Repo

To present quantitative knowledge of photoperiod and temperature on frost hardiness for mathematical modelling, we carried out a growth chamber experiment for second-year Scots pine (Pinus sylvestris L.) seedlings. There were three treatments involved in the trial: a short photoperiod (7 h light : 17 h dark cycle) with a high temperature (15 °C) (SDHT), a short photoperiod (7 h light : 17 h dark cycle) with a low temperature (2 °C), and a long photo period (16 h light : 8 h dark cycle) with a low temperature (2 °C). The following variables were measured: (i) the frost hardiness of stems, needles, buds, and roots by controlled freezing tests, (ii) the electrical impedance spectroscopy (EIS) parameters of the stems, (iii) the chlorophyll fluorescence (Fv/Fm) of the needles, (iv) the dry mass/fresh mass ratio, and (v) the total soluble sugar and starch concentration of the stems, needles, and roots in the non-frost-exposed organs. There was a clear difference in hardiness among the organs by the end of the experiment. Stems by some EIS parameters, needles by Fv/Fm, and stems, needles, and roots by sugar concentration differed among treatments. A stationary level of frost hardiness was reached or asymptotically approached in all organs and treatments except in the SDHT treatment of buds. Very little support was found for the concept of additive effects by photoperiod and temperature. The results show that the additive model needs revision, since the hardening response is dependent on organ, and there is an interaction in the responses to photoperiod and temperature.

HortScience ◽  
2020 ◽  
Vol 55 (4) ◽  
pp. 487-495
Author(s):  
Ming-Wei S. Kao ◽  
Jeffrey K. Brecht ◽  
Jeffrey G. Williamson

The physical and chemical characteristics of two melting flesh (MF) cultivars, TropicBeauty and Flordaprince, and two non-melting flesh (NMF) cultivars, UFSun and Gulfking, with advancing maturities, were determined at harvest, after ripening at 20 °C for 7 days (i.e., direct ripening) and after storage at 0 °C for 14 days then ripening at 20 °C for 7 days (i.e., ripening following low temperature storage). The NMF cultivars were able to retain flesh firmness better than the MF cultivars as fruit matured and ripened on the tree and after the two storage treatments. The NMF fruit of the least mature to the most advanced maturity groups (MGs) were ≈2 to 7 times firmer than the MF fruit in the same MGs after ripening in both storage conditions. For both MF and NMF fruit, a significant reduction of titratable acidity (TA) occurred with no significant changes in soluble solids content (SSC) and total soluble sugar (TSS) as maturity and ripening progressed on the tree and after ripening in both storage conditions. Minimum quality standards of “ready for consumption” peaches were used as general guidelines to determine the optimum harvest maturity of all four cultivars. The NMF fruit ripened directly had wider optimum harvest maturity ranges and could be harvested at more advanced stages than the MF fruit. The MF fruit that ripened following low temperature storage needed to be picked at earlier maturity stages than those that were directly ripened. The optimum harvest maturity of NMF UFSun for the low temperature storage treatment was more advanced than that of the other three cultivars due to abnormal softening found in the lower MGs after ripening. Linear correlation analyses showed that the skin ground color (GC) a* values of both MF cultivars and NMF ‘UFSun’ were highly correlated with the flesh color (FC) a* values, suggesting that GC a* values can be an informative harvest indicator for this NMF cultivar instead of the traditionally used FC. The GC a* values also had high linear correlation with TA for all four cultivars, suggesting that TA can be a potential maturity index for both MF and NMF peaches. Significant correlations of GC a* values and flesh firmness (GC-FF) were found in all four cultivars in one year but only in MF peaches in both years, showing that flesh firmness was the most consistent maturity indicator for the MF cultivars in this study.


Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2547
Author(s):  
Susmita Dey ◽  
Ashok Biswas ◽  
Siqi Huang ◽  
Defang Li ◽  
Liangliang Liu ◽  
...  

To address the demand for natural fibers, developing new varieties that are resistant to abiotic stress is necessary. The present study was designed to investigate the physiological and biochemical traits of three varieties of C. capularis (Y49, Y38, and Y1) and four varieties C. olitorius (T8, W57, M33, M18) under low temperature to identify the cold-tolerant varieties and elucidate the mechanisms involved in enhancing cold tolerance. Research findings revealed that the varieties Y49 and M33 exhibited the highest chlorophyll and carotenoid content. Biochemical profiles revealed that varieties Y49 and M33 were found to be able to withstand low-temperature stress by accumulating different enzymatic and non-enzymatic antioxidants, such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APx), glutathione (GSH), and phenolics, which participated in reducing the content of malondialdehyde (MDA) and hydrogen peroxide (H2O2) caused by low temperature. Osmolytes compounds, such as total soluble sugar, significantly increased in Y49 and M33; and proline content decreased in all varieties except Y49 and M33 after low-temperature exposure. The rise in these osmolytes molecules can be a defense mechanism for the jute’s osmotic readjustment to reduce the oxidative damage induced by low temperature. Furthermore, PCA and hierarchical cluster analysis distinguished the seven varieties into three separate groups. Results confirmed that group I (Y49 and M33 varieties) were low-temperature tolerant, group II (M18, W57) were intermediate, whereas III groups (Y38, T8, and Y1) were low temperature susceptible. PCA also explained 85.72% of the variance of raw data and clearly distinguished three groups that are similar to the cluster heat map. The study thus confirmed the tolerance of selected varieties that might be an efficient adaptation strategy and utilized them for establishing breeding programs for cold tolerance.


1998 ◽  
Vol 28 (4) ◽  
pp. 557-565 ◽  
Author(s):  
Aija Ryyppö ◽  
Tapani Repo ◽  
Elina Vapaavuori

The hardening of hydroponically cultured Scots pine (Pinus sylvestris L.) seedlings and their recovery after freezing was studied at the end of the second growing season (LD), after 3 weeks of short day treatment (SD), after a gradual decrease in temperature to 5°C over 4 weeks (H1), and after 4 weeks at 5°C (H2). Frost hardiness was determined by several methods and the recovery as survival of the seedlings. The highest frost hardiness was achieved in the distal parts of needles (-21 to -27°C) and in the proximal parts of needles (-18 to -25°C), followed by woody roots (-7 to -9°C), the 1-year-old and current stem (-8°C), and the fine roots (-5°C), all at the end of H2. Hardening of needles was induced by SD, but the stem and woody roots started to harden later, as a response to low temperature. As a result of frost treatment during LD and SD, potential plasma membrane roman H+-ATPase activity of roots decreased as electrolyte leakage increased and extracellular resistance decreased, but this relationship was lost during H1 and H2. The present study demonstrates the lack of hardening capacity in the fine roots of Scots pine seedlings at nonfreezing temperatures and the increased mortality of the young seedlings having frost damage on roots.


Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 127
Author(s):  
Pedro García-Caparrós ◽  
Cristina Velasquez Espino ◽  
María Teresa Lao

The reuse of drainages for cultivating more salt tolerant crops can be a useful tool especially in arid regions, where there are severe problems for crops water management. Dracaena deremensis L. plants were cultured in pots with sphagnum peat-moss and were subjected to three fertigation treatments for 8 weeks: control treatment or standard nutrient solution (D0), raw leachates from Chrysalidocarpus lutescens H. Wendl plants (DL) and the same leachate blending with H2O2 (1.2 M) at 1% (v/v) (DL + H2O2). After harvesting, ornamental and biomass parameters, leaf and root proline and total soluble sugar concentration and nutrient balance were assessed in each fertigation treatment. Plant height, leaf and total dry weight had the highest values in plants fertigated with leachates with H2O2, whereas root length, leaf number, RGB values and pigment concentration declined significantly in plants fertigated with leachates from C. lutescens with or without H2O2. The fertigation with leachates, regardless of the presence or absence of H2O2 increased root and leaf proline concentration. Nevertheless, root and leaf total soluble sugar concentration did not show a clear trend under the treatments assessed. Regarding nutrient balance, the addition of H2O2 in the leachate resulted in an increase in plant nutrient uptake and efficiency compared to the control treatment. The fertigation with leachates with or without H2O2 increased nitrogen and potassium leached per plant compared to plants fertigated with the standard nutrient solution. The reuse of drainages is a viable option to produce ornamental plants reducing the problematic associated with the water consumption and the release of nutrients into the environment.


Holzforschung ◽  
2020 ◽  
Vol 74 (11) ◽  
pp. 1021-1032 ◽  
Author(s):  
Sami Hiltunen ◽  
Arttu Mankinen ◽  
Muhammad Asadullah Javed ◽  
Susanna Ahola ◽  
Martti Venäläinen ◽  
...  

AbstractWood decay is an economically significant process, as it is one of the major causes of wood deterioration in buildings. In this study, the decay process of Scots pine (Pinus sylvestris) samples caused by cellar fungus (Coniophora puteana) was followed by nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) methods. Altogether, 30 wood sample pieces were exposed to fungus for 10 weeks. Based on the decrease of the dry mass, the samples were categorized into three classes: decomposed (mass decrease 50–70%), slightly decomposed (10–50%), and nondecomposed (<10%). MRI made it possible to identify the active regions of fungus inside the wood samples based on the signal of free water brought by the fungus and arisen from the decomposition of wood carbohydrates. MRI implies that free water is not only created by the decay process, but fungal hyphae also transports a significant amount of water into the sample. Two-dimensional 1H T1-T2 relaxation correlation NMR measurements provided detailed information about the changes in the microstructure of wood due to fungal decomposition. Overall, this study paves the way for noninvasive NMR and MRI detection of fungal decay at early stages as well as the related structural changes.


Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1313
Author(s):  
Md. Jahirul Islam ◽  
Byeong Ryeol Ryu ◽  
Md. Obyedul Kalam Azad ◽  
Md. Hafizur Rahman ◽  
Md. Soyel Rana ◽  
...  

The effect of exogenously applied putrescine (Put) on salt stress tolerance was investigated in Panax ginseng. Thirty-day-old ginseng sprouts were grown in salinized nutrient solution (150 mM NaCl) for five days, while the control sprouts were grown in nutrients solution. Putrescine (0.3, 0.6, and 0.9 mM) was sprayed on the plants once at the onset of salinity treatment, whereas control plants were sprayed with water only. Ginseng seedlings tested under salinity exhibited reduced plant growth and biomass production, which was directly interlinked with reduced chlorophyll and chlorophyll fluorescence due to higher reactive oxygen species (hydrogen peroxide; H2O2) and lipid peroxidation (malondialdehyde; MDA) production. Application of Put enhanced accumulation of proline, total soluble carbohydrate, total soluble sugar and total soluble protein. At the same time, activities of antioxidant enzymes like superoxide dismutase, catalase, ascorbate peroxidase, guaiacol peroxidase in leaves, stems, and roots of ginseng seedlings were increased. Such modulation of physio-biochemical processes reduced the level of H2O2 and MDA, which indicates a successful adaptation of ginseng seedlings to salinity stress. Moreover, protopanaxadiol (PPD) ginsenosides enhanced by both salinity stress and exogenous Put treatment. On the other hand, protopanaxatriol (PPT) ginsenosides enhanced in roots and reduced in leaves and stems under salinity stress condition. In contrast, they enhanced by exogenous Put application in all parts of the plants for most cases, also evidenced by principal component analysis. Collectively, our findings provide an important prospect for the use of Put in modulating salinity tolerance and ginsenosides content in ginseng sprouts.


2019 ◽  
Vol 47 (4) ◽  
pp. 1252-1257
Author(s):  
Ying JIAN ◽  
Guolin WU ◽  
Donghui ZHOU ◽  
Zhiqun HU ◽  
Zhenxuan QUAN ◽  
...  

Wax apple (Syzygium samarangense) is an important tropical fruit tree cultivated in Southeast Asian. It produces red pear-like shape fruits. The fruit flesh is considered high in antioxidants, phenolics, and flavonoids that have a potential to contribute to the human healthy diet, and was proved to have anti-inflammatory and antimicrobial characteristics. To allow year-round marketing of high quality wax apple fruit, growers always perform shading to inhibit new flushes so as to repress vegetative growth and promote reproductive growth. To investigate the effect of shading on carbohydrates, wax apple trees were shaded with sun shade nets under field conditions. The effects of shading on shoot growth were studied and leaf carbohydrate levels of the trees were determined. The results showed that shading inhibit the the growth of the terminal shoots and promoted bud dormancy. Shading also reduced total soluble sugar, sucrose, glucose, fructose, and starch levels of leaves. The results suggested that shading reduced carbohydrate accumulation and repressed vegetative growth.   ********* In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 4, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue. *********


1994 ◽  
Vol 24 (2) ◽  
pp. 306-320 ◽  
Author(s):  
P.B. Reich ◽  
J. Oleksyn ◽  
M.G. Tjoelker

Seedlings of 24 European Scots pine (Pinussylvestris L.) populations were grown in controlled environment chambers under simulated photoperiodic conditions of 50 and 60°N latitude to evaluate the effect of seed mass on germination and seedling growth characteristics. Seeds of each population were classified into 1-mg mass classes, and the four classes per population with the highest frequencies were used. Photoperiod had minimal influence on seed mass effects. Overall, seed mass was positively related to the number of cotyledons and hypocotyl height. Populations differed significantly in seed mass effect on biomass. In northern populations (55–61°N), dry mass at the end of the first growing season was little affected by seed mass. However, dry mass in 9 of 15 central populations (54–48°N) and all southern (<45°N) populations correlated positively with seed mass. Relative growth rate was not related to seed mass within or across populations, and thus early growth is largely determined by seed mass. Relative growth rate also did not differ among populations, except for a geographically isolated Turkish population with the highest seed mass and lowest relative growth rate. After one growing season, height was positively correlated (r2 > 0.6) with seed mass in 15 populations. To check the duration of seed mass effects, height growth of 1- to 7-year-old field experiments established with the same seed lots were compared. Seed mass effects on height were strongest for 1-year-old seedlings and declined or disappeared by the age of 5–7 years among central and southern populations, but remained stable over that time in northern populations.


2021 ◽  
Author(s):  
Lynn Doran ◽  
Amanda P. De Souza

Quantification of total soluble sugars (as glucose) in plant tissue extracts via the sulfuric phenol method adapted for 96 well plates.


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