scholarly journals Foliar Growth Regulator Sprays Induced Tolerance to Combined Heat Stress by Enhancing Physiological and Biochemical Responses in Rice

2021 ◽  
Vol 12 ◽  
Author(s):  
Alvaro Daniel Pantoja-Benavides ◽  
Gabriel Garces-Varon ◽  
Hermann Restrepo-Díaz
Keyword(s):  
Heat Stress ◽  
Canopy Temperature ◽  
Plant Canopy ◽  
Total Chlorophyll ◽  
Fresh Weight ◽  
Stress Control ◽  
Rice Plants ◽  
Total Chlorophyll Content ◽  
Rice Genotypes ◽  
Nighttime Temperatures

Rice yield has decreased due to climate variability and change in Colombia. Plant growth regulators have been used as a strategy to mitigate heat stress in different crops. Therefore, this study aimed to evaluate the effect of foliar applications of four growth regulators [auxins (AUX), brassinosteroids (BR), cytokinins (CK), or gibberellins (GA)] on physiological (stomatal conductance, total chlorophyll content, Fv/Fm ratio, plant canopy temperature, and relative water content) and biochemical (Malondialdehyde (MDA) and proline contents) variables in two commercial rice genotypes exposed to combined heat stress (high day and nighttime temperatures). Two separate experiments were carried out using plants of two rice genotypes, Fedearroz 67 (“F67”) and Fedearroz 2000 (“F2000”) for the first and second experiments, respectively. Both trials were analyzed together as a series of experiments. The established treatments were as follows: absolute control (AC) (rice plants grown under optimal temperatures (30/25°C day/nighttime temperatures), heat stress control (SC) [rice plants only exposed to combined heat stress (40/30°C)], and stressed rice plants and sprayed twice (5 days before and after heat stress) with a plant growth regulator (stress+AUX, stress+BR, stress+CK, or stress+GA). The results showed that foliar CK sprays enhanced the total chlorophyll content in both cultivars (3.25 and 3.65 mg g−1 fresh weight for “F67” and “F2000” rice plants, respectively) compared to SC plants (2.36 and 2.56 mg g−1 fresh weight for “F67,” and “F2000” rice plants, respectively). Foliar CK application also improved stomatal conductance mainly in “F2000” rice plants compared to their heat stress control (499.25 vs.150.60 mmol m−2s−1). Foliar BR or CK sprays reduced plant canopy temperature between 2 and 3°C and MDA content in plants under heat stress. The relative tolerance index suggested that foliar CK (97.69%), and BR (60.73%) applications helped to mitigate combined heat stress mainly in “F2000” rice plants. In conclusion, foliar BR or CK applications can be considered an agronomic strategy to help to ameliorate the negative effect of combined heat stress conditions on the physiological behavior of rice plants.

scholarly journals Improving the Keeping Quality and Vase Life of Cut Alstroemeria Flowers by Pre and Post-harvest Salicylic Acid Treatments

2013 ◽  
Vol 5 (3) ◽  
pp. 364-370 ◽  
Author(s):  
Elnaz SOLEIMANY-FARD ◽  
Khodayar HEMMATI ◽  
Ahmad KHALIGHI
Keyword(s):  
Salicylic Acid ◽  
Water Balance ◽  
Chlorophyll Content ◽  
Water Loss ◽  
Vase Life ◽  
Total Chlorophyll ◽  
Cut Flowers ◽  
Fresh Weight ◽  
Total Chlorophyll Content ◽  
Keeping Quality

Keeping quality and length of vase life are important factors for evaluation of cut flowers quality, for both domestic and export markets. Studding the effect of pre- and post-harvest salicylic acid applications on keeping quality and vase life of cut alstroemeria flowers during vase period is the approach taken. Aqueous solutions of salicylic acid at 0.0 (with distilled water), 1, 2 and 3 mM were sprayed to run-off (approximately 500 mL per plant), about two weeks before flowers harvest. The cut flowers were harvested in the early morning and both of cut flowers treated (sprayed) and untreated were kept in vase solutions containing salicylic acid at 0.0 (with distilled water), 1, 2 and 3 mM. Sucrose at 4% was added to all treatments as a base solution. The changes in relative fresh weight, water uptake, water loss, water balance, total chlorophyll content and vase life were estimated during vase period. The results showed that the relative fresh weight, water uptake, water balance, total chlorophyll content and vase life decreased significantly while the water loss increased significantly during experiment for all treatments. A significant difference between salicylic acid and control treatments in all measured parameters is observed. During vase period, the salicylic acid treatments maintained significantly a more favourable relative fresh weight, water uptake, water balance, total chlorophyll content and supressed significantly water loss, as compared to control treatment. Also, the results showed that the using salicylic acid increased significantly the vase life cut alstroemeria flowers, over control. The highest values of measured parameters were found when plants were treated by pre + post-harvest application of salicylic acid at 3 mM. The result revealed that the quality attributes and vase life of cut alstroemeria flowers were improved by the use of salicylic acid treatment.

Cell membrane stability and chlorophyll content variation in wheat (Triticum aestivum) genotypes under conditions of heat and drought

2016 ◽  
Vol 67 (7) ◽  
pp. 712 ◽  
Author(s):  
Shoaib Ur Rehman ◽  
Muhammad Bilal ◽  
Rashid Mehmood Rana ◽  
Muhammad Naveed Tahir ◽  
Muhammad Kausar Nawaz Shah ◽  
...  
Keyword(s):  
Heat Stress ◽  
Drought Stress ◽  
Cell Membrane ◽  
Chlorophyll Content ◽  
Chlorophyll A ◽  
Stress Conditions ◽  
Seedling Stage ◽  
Total Chlorophyll ◽  
Cell Membrane Stability ◽  
Total Chlorophyll Content

Heat and drought are among the major obstacles confronting crop production under climate change. The present study was conducted to evaluate 50 diverse wheat genotypes for cell membrane stability (CMS) and chlorophyll content at seedling and anthesis stages under heat and drought stress conditions, to understand the effect of the two abiotic factors and to find promising genotypes for future breeding. Experiments were conducted in the glasshouse (seedling stage) and the field (anthesis stage). Analysis of variance showed significant variation (P ≤ 0.05) for all of the traits at seedling and anthesis stages. High levels of broad-sense heritability and genetic advance at 5% selection intensity indicated the presence of a high genetic component of variation and potential for genetic improvement through selection among the existing genetic variation. CMS showed a significant positive correlation with 1000-grain weight (TGW) under heat and drought conditions at both seedling and anthesis stages. Chlorophyll a/b ratio at seedling stage exhibited a significant negative correlation (r = –0.39, P < 0.05) with TGW under heat stress. Total chlorophyll content was significantly (r = 0.42, P < 0.05) correlated with TGW under heat stress at anthesis. Genotypes ETAD248 and ETAD7 showed the highest CMS and TGW values, whereas their chlorophyll a/b values were lowest, at both seedling and anthesis stages under heat and drought stress conditions. Higher CMS and total chlorophyll content, and lower chlorophyll a/b, were found to be useful indicators to identify genotypes with high TGW under heat and drought stress conditions. This study indicated the possibility of using seedling resistance as an indicator for later stage response in breeding for heat and drought resistance. The resistant genotypes identified can be used as potential germplasm in breeding programs.

scholarly journals Salinity induced deleterious effects on germination, growth, physiological and biochemical process of two varieties of groundnut (Arachis hypogaea L.)

2020 ◽  
Vol 5 (2) ◽  
pp. 144-150
Author(s):  
Sharmin Akter ◽  
Dilruba Yeasmin Jharna ◽  
Sujan Kanti Mali ◽  
Abu Sayeed
Keyword(s):  
Salt Stress ◽  
Chlorophyll Content ◽  
Arachis Hypogaea ◽  
Dry Weight ◽  
Chlorophyll B ◽  
Total Chlorophyll ◽  
Fresh Weight ◽  
Total Chlorophyll Content ◽  
Arachis Hypogaea L ◽  
Physiological And Biochemical

The present study was accomplished to find out the effects of salinity on germination, growth, physiological and biochemical processes of two different groundnuts (Arachis hypogaea L.), varieties viz., Dacca-1, and Zhinga groundnut. The experiments consisted of five salinity treatments viz., control (no salinity), 3, 6, 9, and 12dS/m during germination and vegetative stage of groundnut varieties. Results showed that germination percentage of both the groundnut varieties was significantly decreased with the increase of salt concentration. During the germination stage, maximum shoot and root length, shoot and root fresh weight and shoot and root dry weight of groundnut varieties were recorded from Zhinga groundnut variety at salt stress. The same result occurred during the vegetative stage of Dacca-1 variety while the Zhinga groundnut variety showed maximum parameters than Dacca-1. Fresh weight, as well as dry weight, of shoots and roots of both the groundnut varieties was also decreased with the increase of salt concentrations while leaf proline concentrations were increased among these varieties. Salinity caused significant (P<0.001) reduction in chlorophyll a, chlorophyll b, and total chlorophyll content in both the genotypes. Between two genotypes, Zhinga groundnut recorded higher chlorophyll a, chlorophyll b and total chlorophyll content than Dacca-1. From the studies, it is concluded that the groundnut genotype Zhinga was identified as the tolerant genotype to salt stress than Dacca-1. Overall results indicate that high salinity condition is not suitable for growing the groundnut.

scholarly journals Heat stress-induced changes in shoot and root characteristics of genotypes of tepary bean (Phaseolus acutifolius A. Gray), common bean (Phaseolus vulgaris L.) and their interspecific lines

2021 ◽  
pp. 51-59
Author(s):  
Ligia Carmenza Muñoz ◽  
Mariela Rivera ◽  
Jaime E. Muñoz ◽  
Fatma Sarsu ◽  
Idupulapati M. Rao
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Stomatal Conductance ◽  
Common Bean ◽  
Photosynthetic Efficiency ◽  
Total Chlorophyll ◽  
Phaseolus Vulgaris L ◽  
Tepary Bean ◽  
Phaseolus Acutifolius ◽  
Total Chlorophyll Content

Heat stress is a major limitation to grain yield in common bean (Phaseolus vulgaris L.). Tepary bean (Phaseolus acutifolius A. Gray) is better adapted to heat stress than common bean. Ten tepary bean accessions, four common bean genotypes and four interspecific lines involving P. vulgaris and P. acutufolius, P. coccineus and P. dumosus were evaluated for tolerance to heat stress conditions induced under greenhouse conditions and these were compared to plants grown under ambient temperatures. The high temperature treatment was 29 ±5 °C during the day and was >24 °C (up to 27 °C) during the night, while the ambient temperature (AT) treatment was 25 ±5 °C during the day and 19± 2 °C at night. The genotypic differences were evaluated for morpho-physiological characteristics of shoot and root and also yield components. The Genotype and Genotype × Temperature interactions were significant for all shoot and root morpho-physiological characteristics evaluated. Higher temperature (HT) significantly affected leaf photosynthetic efficiency, total chlorophyll content, and stomatal conductance. The effect was positive or negative, depending on the genotypes. Tepary accessions showed reduced total chlorophyll content, while common bean genotypes and the interspecific lines were less affected. Tepary accessions also showed reduced stomatal conductance, but increased leaf photosynthetic efficiency under HT. Common bean genotypes increased stomatal conductance and decreased leaf photosynthetic efficiency. High temperature decreased total root length, specific root length and pod biomass compared to ambient conditions, but there was no marked effect on pollen viability of the tested genotypes. The superior adaptation of tepary germplasm accessions to high temperature is attributed to their ability to regulate stomatal opening and photosynthetic efficiency, together with a superior ability to remobilize photosynthates from older leaves to pods during physiological maturity

scholarly journals Effects of nano silver on the growth of banana (Musa spp.) cultured in vitro

2018 ◽  
Vol 10 (2) ◽  
pp. 92-98 ◽  
Author(s):  
Dang Giap Do ◽  
Thi Kim Thuy Dang ◽  
Thi Huyen Trang Nguyen ◽  
Thi Duoc Nguyen ◽  
Trong Tuan Tran ◽  
...  
Keyword(s):  
Chlorophyll Content ◽  
Dry Weight ◽  
Total Chlorophyll ◽  
Fresh Weight ◽  
Nano Silver ◽  
Positive Effects ◽  
Total Chlorophyll Content ◽  
Number Of Leaves ◽  
The One

Nano silver has positive effects on the growth and development of in vitro plants. In this study, shoots of in vitro banana with 1 cm in length were cut off the tip which was cultured in Murashige and Skoog (MS) medium supplemented with 30 g.L-1 sucrose, 15% coconut water (v/v), 5 mg. L-1 6-Benzyladenine (BA), 8 g.L-1 agar and nano silver (1, 3, 5, 7 ppm). After twenty days cultured, shoots in the medium supplemented with 1 ppm nano silver have grown well with 8.4 times multiplication and total chlorophyll content (2.05 mg.g-1), three-fold higher than in the control experiment. All new shoot samples were cultivated in a new medium with same component and supplemented with 1 mg. L-1 active charcoal to study root formation. The results showed that the best medium for root development was the one with 3 ppm nano silver. In this treatment, the height of shoots, number of leaves, number of roots, root length, fresh weight, dry weight and total chlorophyll content were 2.90 cm, 4.40 leaves per explant, 7.10 roots per explant, 7.7 cm per explant, 1.47 g per explant, 0.136 g and 3.17 mg.g-1, respectively. In vitro healthy seedlings with equal size were grown in nurseries. Different concentrations of nano silver (5, 10, 15 ppm) were sprayed on once a week. After 30 days, the highest quality result was observed at concentration 5 ppm with shoot of 4.86 cm in length, 5.20 leaves per shoot, 4.60 roots per explant, root of 4.87 cm in length and 3.07 g per explant in fresh weight. Nano bạc có tác động tích cực lên quá trình sinh trưởng và phát triển của một số loài thực vật nuôi cấy in vitro. Trong nghiên cứu này, chồi non in vitro có chiều cao 1 cm đã cắt bỏ đỉnh được nuôi cấy trên môi trường MS có bổ sung 30 g/L đường, 15% nước dừa (v/v), 5 mg/L BA, 8 g/L agar và nano bạc ở nồng độ 1, 3, 5, 7 ppm. Sau 20 ngày nuôi cấy, mẫu cấy phát triển tốt trên môi trường bổ sung nano bạc nồng độ 1 ppm với hệ số nhân chồi 8,4 lần, hàm lượng chlorophyll tổng số đạt 2,05 mg/g, cao gấp ba lần so với mẫu đối chứng. Mẫu cấy được chuyền sang môi trường mới có thành phần tương tự và bổ sung thêm 1 mg/L than hoạt tính để khảo sát sự tạo rễ. Kết quả cho thấy mẫu cấy trên môi trường có nồng độ nano bạc 3 ppm phát triển tốt nhất với chiều cao cây 2,90 cm/mẫu; số lá 4,40/ mẫu; số rễ 7,10/ mẫu; chiều dài rễ 7,7 cm/mẫu; khối lượng tươi 1,47 g/mẫu, khối lượng khô 0,136 g/mẫu và hàm lượng chlorophyll tổng đạt 3,17 mg/g. Những cây con in vitro phát triển tốt được trồng ngoài vườn ươm. Các dung dịch nano bạc có nồng độ 5, 10, 15 ppm được dùng để phun lên cây 1 lần/ tuần. Sau 30 ngày, kết quả cao nhất ghi nhận ở dung dịch có nồng độ 5 ppm với chiều cao chồi đạt 4,86 cm, 5,20 lá/chồi, 4,60 rễ/mẫu, chiều dài rễ đạt 4,87 cm và khối lượng tươi đạt 3,07 g/mẫu.

scholarly journals Effect of IBA, NAA and their Combination on Rooting and Biochemical Parameters of Stem Cuttings in Barbados Cherry

2021 ◽  
Vol 8 (5) ◽  
pp. 147-150
Author(s):  
Alam Khan Samim ◽  
B. S. Shivakumar ◽  
Ganapathi M.
Keyword(s):  
Chlorophyll Content ◽  
Chlorophyll A ◽  
Growth Regulators ◽  
Biochemical Parameters ◽  
Root Initiation ◽  
Stem Cuttings ◽  
Chlorophyll B ◽  
Total Chlorophyll ◽  
Fresh Weight ◽  
Total Chlorophyll Content

An investigation was to assess the influence of growth regulators IBA, NAA and their combination on rooting and biochemical parameters of stem cuttings in Barbados cherry. It was observed that, the least number of days (21.33) taken for root initiation, maximum percentage of rooting (80.00) was observed in cutting treated with IBA 5000 ppm followed by IBA 4500 ppm over other treatments. Significantly highest Chlorophyll-a (1.26), Chlorophyll –b (0.55) and total chlorophyll content (1.82 mg/g of fresh weight) of leaves and C : N ratio (8.74) was observed in cuttings treated with IBA 5000 ppm followed by IBA 4500 ppm over all other treatments.

Phenological and Physiological Study of Six Cultivars of Ziziphus spp. Planted in Basra Province- Iraq.

2016 ◽  
Vol 6 (2) ◽  
pp. 981-995
Author(s):  
Manal Zbary Al Mayahi
Keyword(s):  
Dry Weight ◽  
Growing Season ◽  
Physiological Characteristics ◽  
Total Acidity ◽  
Total Chlorophyll ◽  
Fresh Weight ◽  
Weight Percentage ◽  
Total Chlorophyll Content ◽  
Calcium Pectate ◽  
Significant Superiority

This study was conducted in a private orchard at Abu Al Khasib area in Basra province – Iraq, during the growing season (2013), to evaluate six cultivars of Ziziphus spp. Plant, phenologically and physiologically. The results confirmed a difference among the cultivars in some phenological characteristics, and a similarity in others. While in physiological characteristics, and a similarity in others. While in physiological characteristics the study showed a significant superiority of the Toffahi cultivar in its length, diameter and weight of fruits (4.00 cm, 3.26 cm and 7.30 g.) respectively and in its fruit dry weight percentage (42.38 %), while the Hindi cultivar was superior in the T.S.S., water content and phenols percentages (17.22, 67.36 and 2.21 %) respectively. But the Laimoni cultivar was superior in leaf area, adjustable total acidity percentage and calcium pectate percentage (6.78 cm2, 0.81 % and 4.57%) respectively. While Bathri cultivar was significantly superior in total chlorophyll content (3.36 mg. 100-1 fresh weight). Whilst the rest of cultivars showed a variable differences among them.

scholarly journals Evaluation of Early Stage Traits as an Indicator of Genetic Variation in Winter Lentil

2021 ◽  
Vol 5 (3) ◽  
pp. 552-559
Author(s):  
Murat ERMAN ◽  
Fatih ÇIĞ ◽  
Figen CERİTOĞLU ◽  
Mustafa CERİTOĞLU
Keyword(s):  
Genetic Variation ◽  
Chlorophyll Content ◽  
Plant Height ◽  
Early Stage ◽  
Stem Diameter ◽  
Field Conditions ◽  
Total Chlorophyll ◽  
Fresh Weight ◽  
Important Indicator ◽  
Total Chlorophyll Content

Lentil is one of the oldest cultured crops with cereals which are cultivated in the wide geography of the world due to its high adaptability, quality nutritional value, important usage areas and economic value. Morphological, physiological and biochemical parameters during the early vegetative stage are an important indicator of adaptation to environmental conditions. This study was carried out to investigate the variation on some agronomic and physiological traits of 49 lentil genotypes during the early growth stage. Although there were significant differences in terms of plant height and total chlorophyll content, differences between genotypes for plant dry and fresh weight, stem diameter and length of epicotyl were statistically found insignificant. Plant height, plant fresh weight, plant dry weight, length of epicotyl, stem diameter and total chlorophyll content varied between 2.53-4.78 cm, 0.17-0.39 g, 0.04-0.13 g, 1.53-3.00 cm, 0.72-1.05 cm and 28.4-38.2%, respectively. As a result, it was determined that observations taken 30 days after emergence are not sufficient to constitute genetic variation and use as an early prediction criteria field conditions. The longer-term and comprehensive studies should be carried out to form genetic variation and interpret the results in field conditions.

scholarly journals Effect of Relative Air Humidity and High Temperature on the Physiological and Anatomical Responses of Two Rhododendron Cultivars

HortScience ◽  
2019 ◽  
Vol 54 (7) ◽  
pp. 1115-1123
Author(s):  
Wenjie Ma ◽  
Wen Liang ◽  
Bing Zhao
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Vapor Pressure ◽  
Enzymatic Activity ◽  
Stomatal Density ◽  
Total Chlorophyll ◽  
Air Humidity ◽  
Total Chlorophyll Content ◽  
Relative Air Humidity ◽  
Relative Water

The effects of different relative air humidity (RH) levels under high temperature and accompanying vapor pressure deficits (VPDs) on the physiology, photosynthesis, and anatomy of Rhododendron need to be better understood to help in reducing damage to leaves caused by high temperature. In this study, two Rhododendron cultivars were exposed at 45%, 55%, 65%, 75%, and 85% RH to a treatment of constant temperature at 38 °C for 14 days, resulting in a VPD of 3.64, 2.98, 2.32, 1.66, and 0.99 kPa, respectively. The results showed the least reduction of the net photosynthetic rate (Pn) under 75% RH treatment in R. ‘Fen Zhenzhu’ (decreased by 79.8%), and under the 85% RH treatment in R. ‘Zhuangyuan Hong’ (decreased by 75.4%). The decline in relative water content (RWC) was less under the 75% and 85% RH treatments, and electrolyte leakage showed a slight decrease under the 75% RH treatment in the two Rhododendron cultivars. The appearance of the two cultivars under greater RH showed less damage, probably because plants can avoid damage by increasing total chlorophyll content, decreasing stomatal area, stomatal density, and opened stomata ratio, enhancing enzymatic activity and osmoregulation substances, and improving leaf structure. The findings show that greater RH can alleviate damage caused by heat stress and improve thermostability.

scholarly journals Antioxidant gene expression, chlorophyll, and starch content in Persian lime (Citrus latifolia Tanaka Ex Q. Jiménez) trees with HLB by application of elicitors of plant resistance

2021 ◽  
Vol 6 (2) ◽  
pp. 86-102
Author(s):  
Felipe Roberto Flores-de la Rosa ◽  
◽  
Ricardo Santillán-Mendoza ◽  
Cynthia Guadalupe Rodríguez-Quibrera ◽  
Antonio Martínez-Ruiz ◽  
...  
Keyword(s):  
Chlorophyll Content ◽  
Starch Content ◽  
Starch Accumulation ◽  
Economic Losses ◽  
Total Chlorophyll ◽  
Gamma Aminobutyric Acid ◽  
Antioxidant Genes ◽  
Spectrophotometric Methods ◽  
Total Chlorophyll Content ◽  
Randomized Design

Persian lime is economically important for Mexico. However, the disease known as Huanglongbing (HLB) causes chlorosis symptoms in the foliage that affect the growth and decreases the yield of the trees. The expression of chlorosis symptoms is associated with starch accumulation and inhibition of antioxidant activity. The objective of the present work was to determine the effect of the application of three resistance elicitors on the expression of three antioxidant genes and on starch and chlorophyll content in Persian lime trees with HLB. Salicylic acid (SA), jasmonic acid (JA) or gamma-aminobutyric acid (GABA) were applied every eight days for nine weeks using a completely randomized design and a one-way ANOVA was performed for the analysis. Expression of APX, CAT and SOD genes was quantified at week nine at four different times. Starch and total chlorophyll content was estimated every three weeks by spectrophotometric methods. The application of the elicitors significantly increased the expression of the three genes, with SA and GABA generating the greatest increase at different times of application. No difference was found in starch and total chlorophyll content at most of the times evaluated. The use of resistance elicitors is promising in the management of HLB in plots already infected, seeking to extend the productive life of the orchards and thus counteract the economic losses caused by HLB.

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