Original Article
Plant Stress
Simeneh Tamrat Alemu; Amsalu Gobena Roro
Abstract
Purpose: herbaceous dicot plants mainly sweet potato is highly affected by UV-B and light quality based on altitude. Therefore, this study will give insights on the effect of UV-B and light quality on photosynthetic efficiency of sweet potato based on Altitude. Research method: The experimental design ...
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Purpose: herbaceous dicot plants mainly sweet potato is highly affected by UV-B and light quality based on altitude. Therefore, this study will give insights on the effect of UV-B and light quality on photosynthetic efficiency of sweet potato based on Altitude. Research method: The experimental design was laid out in split plot design with factorial arrangement. The treatments consist of +UV-B or control, UV-B exclusion, UV-B+end of day light exclusion, and the two sweet potato cultivars such as Kulfo and Hawassa-83. Main findings: highest UV-B (1693.0mw/m-2s-2) was recorded at highland (2230m.a.s.l) and the lowest (1107mw/m-2s-2) was recorded at lowland (1400m.a.s.l). The result shows that photosynthetic rate increased by 2.41% in Kulfo compared with Hawassa83 cultivar. Also altitude has a highly significant effect on photosynthetic efficiency; the highest stress level 0.68 and 0.72 was recorded at UV-B + EOD exclusion and highland. This indicate UV-B +EOD exclusion cause light quality and intensity stress at highland also UV-B was inducing high stress at highland area and affecting sweet potato productivity but exclusion increase Fv/Fm and stomata conductance it has no effect on photosynthesis and transpiration rate. Limitations: The research has a limitation due to Altitude difference it’s difficult to control factors other than UV-B and light Quality that may cause a difference. Originality/Value: This research tries to assess UV-B and end of day time light quality effects due to altitude difference and encourages new research on UV-B, its adaptation and light quality on crop productivity.
Original Article
Medicinal Plants
Azim Ghasemnezhad; Madeh Ahmadi; Arezu Frouzy
Abstract
Purpose: Due the importance of taxol and based on the confirmed role of certain endophytes of Yew tree in the production of this vital compound, the present study was designed to investigate the effect of isolated endophytic fungi on vegetative and qualitative characteristics of stevia plant. Research ...
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Purpose: Due the importance of taxol and based on the confirmed role of certain endophytes of Yew tree in the production of this vital compound, the present study was designed to investigate the effect of isolated endophytic fungi on vegetative and qualitative characteristics of stevia plant. Research method: The experiment included five different endophytic fungi isolated from Yew tree. In order to do that, rooted cuttings of stevia were transferred to the pot after being inoculated with different isolated endophytic fungi (TB2, TB2-3, TB20, TB55) of Yew tree in four replications as a completely randomized design and were kept in outdoor conditions. To isolate endophytic fungi, root samples were collected from the yew trees in the Ziyarat forest located in Golestan province, Iran. Main findings: The results of the study revealed the positive effect of Yew tree endophytes as biotic agents on the growth and physiological parameters of stevia. Also, the fungal pathogenicity effect on stevia was not observed. In addition, the main stem diameter, internode spacing, leaf area and other measured parameters were affected by studied endophytes. Among of the five used isolates fungi, three were classified as stevia plant grows stimulator. Also, due to the highest total sugar and antioxidant activity of stevia, rest two isolates were classified as “bio-elicitor”. Limitations: There was no limitation to report. Originality/Value: The findings of the present study suggest that stevia, as a medicinal and economical herb, is capable of coexistence with yew endophytes. If taxol producer endophytes successfully transfer to stevia, it is possible to study the production of taxol in herbaceous plants, thereby opening the new door to easier and cheaper access to Taxol.
Original Article
Plant Stress
Fatemeh Sheikh Abol-hasani; Parto Roshandel
Abstract
Purpose: To evaluate the effects of NaCl priming to increase salt tolerance in Dracocephalum moldavica L. an experiment was conducted as factorial based on completely randomized design at Shahrekord University. Research method: Seeds of medicinal plant D. moldavica were primed with NaCl (1 M/ for 24 ...
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Purpose: To evaluate the effects of NaCl priming to increase salt tolerance in Dracocephalum moldavica L. an experiment was conducted as factorial based on completely randomized design at Shahrekord University. Research method: Seeds of medicinal plant D. moldavica were primed with NaCl (1 M/ for 24 h/ at darkness/ under 25˚C) and then 30-day-old plants were introduced to salinity (0, 100 and 150 mM NaCl) for one month. The analyzed parameters consisted of dry weight, leaf area, total water content, leaf relative water content, electrolyte leakage, lipid peroxidation, photosynthetic pigments concentrations, total phenolic content and the activity of antioxidant enzymes. Main findings: NaCl-priming alleviated the injurious effects of salinity in the salinized plants. The biomass increased up to 64.5% and 3-fold at 100 and 150 mM NaCl, compared to exclusively salinity. Ion leakage and lipid peroxidation decreased as well. Moreover, NaCl-priming led to increase leaf area, improve water status, photosynthetic pigments content and antioxidant enzymes activities in favor of improving the biomass of salinized D. moldavica. Total phenolic content increased by salinity alone, but NaCl-priming markedly decreased it at normal condition. The pattern of polyphenols concentration and accumulation was different under NaCl-priming + salinity treatment. Limitations: No special limitations were founded. Originality/Value: Seed priming with NaCl enhanced salt tolerance in D. moldavica through improving water status and photosynthesis, protection of cellular membrane integrity and changes in antioxidant enzyme activity. Alternation in polyphenols concentration might be a signature of changes in the medicinal properties of different parts of this medicinal plant.
Original Article
Plant Stress
Farid Moradinezhad; Soheyla Hajizadegan; Mohammad Hassan Sayyari; Mehdi Khayyat
Abstract
Purpose: Boron toxicity is an important factor, which reduces crop productivity, quality and medicinal characteristics around the world. Research method: This research was conducted to investigate the effect of different boron (B) concentrations on growth, chemical and physiological characteristics of ...
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Purpose: Boron toxicity is an important factor, which reduces crop productivity, quality and medicinal characteristics around the world. Research method: This research was conducted to investigate the effect of different boron (B) concentrations on growth, chemical and physiological characteristics of Satureja hortensis plants under greenhouse conditions in 2016. The experiment was conducted in a glasshouse with 25±3 °C and 15±3 °C (day-night) temperatures, 60% relative humidity and 340 ppm CO2 concentration. Treatments were different B concentrations as H3BO3 that used via irrigation water including 0, 5, 10, 25 and 50 mg L–1. Main findings: Results indicated that total nitrogen, Fm, Fv, Fv/Fm, chlorophyll a, b and total, leaf number, relative water content (RWC), specific leaf weight (SLW), areal fresh and dry weights significantly decreased by B increase. On the other hand, increased B concentration in leaf was led to increasing of F0, ΦN0, proline, total carbohydrate and phenolics, specific leaf area and leaf electrolyte leakage. Limitations: No significant limitation to report. Originality/Value: It is concluded that summer savory can tolerate B concentrations up to 10 mg L–1, and leaf boron accumulation significantly inhibited, however, increased with more B concentration of root medium, which affected all physiological aspects mentioned above.
Original Article
Plant Stress
Seyedeh Laleh Alavi; Nasser Abbaspour
Abstract
Purpose: Soil salinity is a prevalent abiotic stress that adversely affects crop productivity worldwide. Salinity is an environmental stress that limits growth and development in fruits and vegetables due to increasing osmotic pressure, imbalancing of nutrients and toxicity of some special ions. Tomato ...
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Purpose: Soil salinity is a prevalent abiotic stress that adversely affects crop productivity worldwide. Salinity is an environmental stress that limits growth and development in fruits and vegetables due to increasing osmotic pressure, imbalancing of nutrients and toxicity of some special ions. Tomato (Lycopersicon esculentum) is one of the most important fruits and vegetables. Research method: In this study, effect of salt stress (NaCl) on eight cultivars of tomato (king stone, Caligen, Super Strain B, Primo Early, Early Urbana VF, Early Urbana 111, Cal-j-N3 and Peto Early CH) were investigated. Plants were cultured in hydroponic conditions with five treatments of NaCl including 0, 30, 60, 90 and 120 mM. Each test has repeated three times. The growth indices, Ions, chlorophyll, soluble sugar and proline contents, were measured in roots, stems, petioles and leaves. Main findings: The results showed that, sodium and chloride contents increased in all parts of the cultivars with increasing NaCl concentration. However nitrate and potassium contents decreased. Proline and soluble sugars contents increased in leaves under salt stress too. In Primo- Early, Early Urbana 111, Cal-j-N3 and Petoearly CH, soluble sugar content increased with increasing NaCl concentration up to 90 mM. In all varieties, high salinity reduced chlorophyll a and b, total chlorophyll, carotenoids contents and growth indices. As far as the measured factors are concerned, it seems that Early Urbana VF and Super Strain B showed a high capacity to tolerate salinity stress. Limitations: No limitations were founded. Originality/Value: This is an opportunity to identify salinity-tolerant tomato cultivars that play an important role in the cultivation and production of quality crops.
Original Article
Plant Stress
Farhad Azarmi-Atajan; Mohammad Hassan Sayyari-Zohan
Abstract
Purpose: The effect of Pseudomonas sp. rhizobacteria as plant growth-promoting rhizobacteria (PGPR) in alleviating salt stress in the lettuce plant was studied under greenhouse condition. Research Method: The experiment was conducted following a completely randomized design with three replicates. The ...
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Purpose: The effect of Pseudomonas sp. rhizobacteria as plant growth-promoting rhizobacteria (PGPR) in alleviating salt stress in the lettuce plant was studied under greenhouse condition. Research Method: The experiment was conducted following a completely randomized design with three replicates. The treatments include four Pseudomonas sp. strains (B0 (non-inoculated), B1, B2 and B3) as PGPR and three levels of irrigation water salinity (0, 4 and 8 dS m-1 as NaCl). Findings: The results showed that with rising salinity levels the lettuce fresh and dry weight, chlorophyll and carotenoids content and K concentration decreased but, the content of membrane stability index (MSI), Na and Na/K ratio increased. However, inoculation of the lettuce plants by PGPR significantly increased the lettuce fresh and dry weight, chlorophyll and carotenoids content, K concentration and K/Na ratio under various salinity levels. Among the PGPR strain, the B2 strain was more effective in the improvement of the lettuce resistance to salinity stress. Research limitations: If antioxidant compounds and enzymes were measured in this study, it would be helpful to interpret the results. Originality/Value: with regards to the useful impact of the PGPR on the lettuce plant under soil salinity, these microorganisms can be used as biofertilizer to provide nutrients and increase plant resistance to salt stress.
Original Article
Plant Stress
Seyyedeh Atefeh Hosseini; Mehdi Khayyat
Abstract
Purpose: The present research was done to evaluate the responses of ‘Yusef Khani’ (Y) and ‘Malas-e-Yazdi’ (M) Iranian pomegranates to salt stress under field conditions. Research method: Treatments included different salinized water (EC=1.05 as control, 4.61 and 7.46 dS m–1) ...
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Purpose: The present research was done to evaluate the responses of ‘Yusef Khani’ (Y) and ‘Malas-e-Yazdi’ (M) Iranian pomegranates to salt stress under field conditions. Research method: Treatments included different salinized water (EC=1.05 as control, 4.61 and 7.46 dS m–1) and two commercially Iranian pomegranate varieties. Main findings: Interaction of salinity × variety showed the lowest chlorophyll (chl) and potassium (K) level, and the highest chloride (Cl) and sodium (Na) in M variety, under high level of salinity. Although the lowest non-photochemical quenching, and effective quantum yield of photochemical energy conversion in PSII observed in this variety under 7.46 dS m–1, however, basal quantum yield of non-photochemical processes in PSII increased. Accumulation of Na and Cl in leaf tissue increased with increasing salinity in both varieties. Moreover, lower accumulation of calcium (Ca), magnesium (Mg) and iron (Fe) observed in both varieties. More Na and Cl was obtained within leaves of M variety, compared with other one. We found that there were some differences between these varieties and ‘Yousef Khani’ was more tolerant to salinity compared with ‘Malas-e-Yazdi’. Limitations: It might be better to evaluate several varieties for salinity resistance, however, it was impossible to us. Originality/Value: Iran is the main source of genetic variability for pomegranate. There is a huge diversity within pomegranate germplasm that should be studied for salinity and drought resistance. Thus, here we conducted a research to find a salt resistant pomegranate.
Short Communication Article
Postharvest Biology and Technology
Seeseei Molimau-Samasoni; Veronica Vaavia; Ron B. H. Wills
Abstract
Purpose: Breadfruit is a tropical climacteric fruit consumed as an unripe starchy vegetable hence export requires some postharvest technology to inhibit ripening during marketing. Research in the Caribbean found storage at 12 °C was optimal to delay ripening without fruit developing chilling ...
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Purpose: Breadfruit is a tropical climacteric fruit consumed as an unripe starchy vegetable hence export requires some postharvest technology to inhibit ripening during marketing. Research in the Caribbean found storage at 12 °C was optimal to delay ripening without fruit developing chilling injury. Breadfruit is a major horticultural commodity in Samoa with New Zealand a target export destination. This paper examines the ability of low temperatures to extend the storage life of unripe Samoan breadfruit and thus facilitate export. Research method: Puou and Maafala breadfruit were stored at temperatures from 12 to 25 °C and observed for time to ripen and to exhibit chilling injury symptoms as these factors determine storage life. Main findings: Time to ripen increased as the temperature was lowered but chilling injury occurred on all fruit stored at 12 and 15 °C and many stored at 17 °C. The longest storage life was attained at 17 °C with 11 days for Puou and 16 days for Maafala fruit with storage terminated by a mix of fruit ripening and developing chilling injury. Limitations: Questions remain as to the importance of mild chilling injury to influence purchase. Originality/Value: Samoan breadfruit is more chilling sensitive than Caribbean fruit and thus must be transported at higher temperatures than Caribbean fruit. Use of 17 °C gave the longest storage life for Samoan breadfruit which is sufficient for the 10 days required to export by air to New Zealand but is less than the 21 days required to export breadfruit by sea.
Review Article
Olericulture
Flavien Shimira; Fabrice Afloukou; Festus Maniriho
Abstract
Purpose: Potato (Solanum tuberosum) is an important food and cash crop globally, particularly in Rwanda whereby it is ranked fourth most grown food crops after banana, sweet potato and cassava. The purpose of this review study is to analyze and understand potato yield production systems in Rwanda and ...
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Purpose: Potato (Solanum tuberosum) is an important food and cash crop globally, particularly in Rwanda whereby it is ranked fourth most grown food crops after banana, sweet potato and cassava. The purpose of this review study is to analyze and understand potato yield production systems in Rwanda and to find out related constraints. Main findings: After key informants and various research work, it was found that the low potato yield (with on average 11.6 t/ha compared to yield potential of 50.6 t/ha), pests and diseases are the main constraints for potato production in Rwanda. However, it was revealed that the later are highly related to an inadequate supply of good seed tubers. Indeed, it is was reported that the actual mini-tubers seed production systems can cover up to 30% of the national demand; and hence farmers recycle their own seeds or get them from informal sources. This situation is leading to persistent pests and diseases particularly potato bacterial wilt (PBW) and late blight disease hampering potato productivity. Limitations: Soil erosion exacerbated by land fragmentation and use of steep land, and poor fertilization practices both in quantity and quality are reportedly highlighted in this review as secondary bottlenecks for potato production in Rwanda. Directions for future research: Active involvement of the private sector in seed production in conjunction with aeroponic systems and integrated pest and disease management (IPDM) is the promising future research path and most effective approach to be adopted for sustainable potato production and food security in the country.
Review Article
Plant Stress
Puran Bridgemohan; Majeed Mohammed; Ronell S. H. Bridgemohan; Zareef Mohammed
Abstract
Purpose: Significant research on yield improvement of wetland rice provided a greater understanding of stress physiology, but less on ecophysiology of anaerobiosis stress. This paper explores soil conditions that exist because of waterlogging and submergence, reviews the current research of the effect ...
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Purpose: Significant research on yield improvement of wetland rice provided a greater understanding of stress physiology, but less on ecophysiology of anaerobiosis stress. This paper explores soil conditions that exist because of waterlogging and submergence, reviews the current research of the effect of the ecophysiology of abiotic stress, and the plant's adaptability through its various biochemical pathways and physiological processes. Findings: Rice has morphologically avoided anoxia due to flooding and submergence ecosystems through its aerenchyma tissues that facilitate oxygen diffusion from shoot to root-tips. The plant hormone system plays a central role in the initiation and regulation of most of these adaptive responses. The biochemical responses of submerged rice are mainly mechanisms of avoiding internal anoxia as the oxygen deficit shift the energy metabolism to anaerobic, with greater activity of glycolytic pathway, fermentation enzymes, and involvement of antioxidant defense mechanisms to cope with the post hypoxia/anoxia oxidative stress. Physiological processes including aerobic respiration, photosynthesis, and phytochrome photo-equilibrium of the submerged rice shoots have evolved to adapt to waterlogging stress. Most of the post-anoxic injury is due to the generation of reactive oxygen and toxic oxidative products as acetaldehyde, hydrogen peroxide and hydroxyl radical. Limitations: This was minimal due to accessibility to the literature. Directions for future research: Future research should be directed towards rice tolerance to waterlogging as well as low water availability and salinity.
Review Article
Tropical Fruits
Fabrice Afloukou; Laurence Dossou; Valerien Zinsou
Abstract
Purpose: In sub-Sahara Africa, citrus is mainly cultivated in the coastal countries. It plays important nutritional and socio-economical roles by providing vitamins and minerals to consumers and cash to farmers. The crop is being challenged by many constraints. The purpose of this review is to inventory ...
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Purpose: In sub-Sahara Africa, citrus is mainly cultivated in the coastal countries. It plays important nutritional and socio-economical roles by providing vitamins and minerals to consumers and cash to farmers. The crop is being challenged by many constraints. The purpose of this review is to inventory the virus and virus-like diseases known to infect citrus in the West-Africa up today. Findings: Less attention is given to citrus in West African countries while the crop is imperiled by biotics as well as abiotic constraints. Then, it is threatened by several diseases. Among them, the updated reported virus and virus-like diseases are tristeza, exocortis, citrus psorosis complex, cachexia, stubborn and greening. There is no recent update regarding the incidence, severity, and distribution of those diseases as well as their impact on yield. The biological or molecular characterization of the diseases' causal agents also still lack. Research limitations: There is no effective national or regional plant protection policy; leading to the persistence of citrus diseases and wide-spreading infections. Climate change is enhancing the dilemma. Directions for future research: The sustainable production of citrus in the region requires new plant protection policies and investigations regarding citrus diseases and their vectors. Furthermore, rootstocks screening is required in every single agro-ecological zones where citrus is grown for the simultaneous management of citrus viroids, viruses, and soil-born fungi.
Original Article
Plant Stress
Esmaeil Jadidi; Maryam Tatari; Mahmoud Ghasemnezhad; Hamid Reza Salemi
Abstract
Purpose: Identification of pomegranate cultivars with higher tolerance to salinity stress was the purpose of the current study. Research Method: One-year-old rooted cuttings of the pomegranate cultivars including 'Malase Saveh' ('M-Saveh'), 'Malase Isfahan' ('M-Isfahan'), 'Robabe Ghermeze Shiraz' ('Robab'), ...
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Purpose: Identification of pomegranate cultivars with higher tolerance to salinity stress was the purpose of the current study. Research Method: One-year-old rooted cuttings of the pomegranate cultivars including 'Malase Saveh' ('M-Saveh'), 'Malase Isfahan' ('M-Isfahan'), 'Robabe Ghermeze Shiraz' ('Robab'), 'Gabrie Yazd' ('G-Yazd'), Gabrie Torshe Yazd' ('GT-Yazd'), 'Zaghe Sefide Yazd' ('ZS-Yazd'), 'Zaghe Torshe Yazd' ('ZT-Yazd') and 'Malase Torshe Pishva' ('M-Pishva') were cultured in plastic pots and treated with different concentrations of sodium chloride in irrigation water including 0 (control), 3, 6, 9 and 12 dS m-1. Findings: At 12 dS m-1salinity level, the lowest decrease in plant height was observed in 'Robab', and 'M-Pishva' and the lowest decrease in the plant diameter was recorded in 'ZT-Yazd' and 'G-Yazd'. At the same salinity level, 'GT-Yazd' showed the lowest percentage of increase in electrolyte leakage (EL) compared to the control (23%). The highest increase in proline content was observed at 9 dS m-1 salinity for 'ZS-Yazd' and at 12 dS m-1 salinity for 'GT-Yazd'. At high salinity levels, leaf chlorophyll content decreased in pomegranate cultivars compared to the control. The activity of peroxidase enzyme in 'M- Pishva', ZT-Yazd' and 'GT-Yazd' followed an increasing and then decreasing with increasing salinity levels. The activity of the superoxide dismutase enzyme was highest in 'G-Yazd', 'M-Isfahan' and 'Robab'. Limitations: Investigation of salinity tolerance in pots is one of the limitations of this study. Originality/Value: Yazd cultivars including 'G-Yazd', 'GT-Yazd', 'ZS-Yazd' and 'ZT-Yazd' were more tolerant to salinity stress.
