Mekhled Alenazi

A field study was conducted to understand the effectiveness of foliar applications of ZnO-NPs (0, 50, 100 mg L−1) and SiO2-NPs (0, 25, 50 mg L−1) on potato plant growth, morphology, nutrient uptake, oxidative stress, and antioxidative response under drought conditions (i.e., 100% crop evapotranspiration ETc, 75% ETc, and 50% ETc). Results revealed that water deficiency significantly hampered plant growth and biomass production and stimulated oxidative stress in potatoes. However, the exogenous application of ZnO-NPs and SiO2-NPs significantly improved plant growth attributes such as the number of branches, plant height, fresh and dry biomass, leaf area, and leaf area index as compared with untreated plants. The foliar application of ZnO-NPs (i.e., 100 and 50 mg L−1) and SiO2-NPs (50 mg L−1) promoted the mineral ion accumulation in plants grown under water deficiency and thus resulted in higher NPK, Zn2+, Fe2+, and Mn2+ contents. A significant reduction in malondialdehyde (MDA) and h...

Cadmium (Cd) is one of the highly toxic, non-essential heavy metals that inhibit plant growth and development by prompting chlorophyll loss and affecting photosynthetic activities. This study investigated the efficacy of Spirulina platensis and Sargassum polycystum extracts in alleviating Cd stress in Pak Choi at morpho-biochemical, anatomical, and molecular levels. Different concentrations (0, 25, 50, and 100 mL/L) of S. polycyctum (SAR), S. platensis (SPI), and a mixture of both extracts (SS) were exposed to 100 mg/kg Cd-contaminated Pak Choi seedlings. Non-Cd-treated Pak Choi and Cd-contaminated Pak Choi without algal extracts were assigned as positive and negative controls, respectively. The results showed that the application of algal extracts increased the plant height, fresh weight (FW), and dry weight (DW) as the extract level increased. This was greatest in 100SS with 37.51% (shoot length), 68.91% (root length), 110.8% (shoot DW), and 216.13% (root DW), while an increase of...

The wax apple or jambu madu, is a non-climacteric tropical fruit from Myrtaceae family and widely cultivated in South East Asia. The limited availability of good quality seedlings of wax apple is the main problem to development of flourish it’s market share in the current fruit industry. Therefore, in order to produce good quality planting materials, a study aimed at optimizing propagation and adventitious rooting technique and survivability of wax apple air layer was conducted. In this study, four different levels of Indole-3-Butyric Acid (IBA) concentration (0, 1000, 1500 and 2000 mg L-1) and three rooting media (sphagnum moss, vermicompost and garden soil) were applied after removal of bark (phloem) on the shoot to determine the effect on rooting and survivability of the wax apple air layer under field conditions. The results showed that the wax apple shoots treated with 2000 mg L-1 IBA produced the significantly higher number of roots, increased length of root, diameter of branc...

The genetic diversity assessment of agricultural crops is crucial for breeding programs aimed at enhancing crop yield, resistance to diseases, and adaptation to changing environmental conditions. In the present investigation, a comparative genetic relationship in sixteen onion genotypes was assessed utilizing dominant (RAPD) and co-dominant (SSR) marker systems. Ten RAPD and nine SSR markers showed genetic diversity remarkably and produced 503 and 107 amplicons respectively. Spearman rank correlation was used to compare the different efficiency parameters in two marker systems with respect to sixteen onion genotypes. The genetic relationship based on similarity matrix values between a pair of cultivars was higher for SSR markers than for the RAPD marker system. OPC-04 (RAPD primer) and ACM-004 (SSR primer) witnessed the highest poly-morphic bands along with other polymorphic markers that proved to be useful in grouping onion genotypes. Finally, dendrograms were constructed and compa...

The present study aimed to investigate the effects of AMF on the growth and physio-biochemical attributes, antioxidant enzyme activities, plant growth regulators and inorganic nutrients in tomato grown under salt stress condition. Tomato plants were exposed to different concentrations of NaCl alone (0, 50 and 150 mM) and in combination with AMF (0mM+AMF, 50mM+AMF and 150mM+AMF). Spore population and colonization, growth and biomass yield, pigments, membrane stability index and malondialdehyde were negatively affected. Exposure of plants to combination of NaCl and AMF showed positive impact on the above parameters. Proline and antioxidant enzyme activity increased with increasing concentration of NaCl and further increase was observed in plants treated with NaCl in combination with AMF. Acid and alkaline phosphatase, hydrolytic enzymes and pectinase are also affected with increasing concentration of salt. However plants treated with NaCl in combination with AMF balances the above enz...

Growth improvement of the medicinal plant, Ficus deltoidea (Mas Cotek) under drought conditions is a vital issue in Malaysia since it is a slow-growing plant and disposed to leaf damage under the stresses of drought. Therefore, investigation was done to examine the outcomes of hydrogen peroxide (H2O2) application on Rubisco gene expression and metabolites accumulation of stressed F. deltoidea plants, and thereby to record the changes in leaf histology, photosynthesis, biochemical properties, and the growth of the plant. H2O2 at the rates of 0, 5, 10, 15, and 20 mM were foliar sprayed biweekly on the drought stressed plants using a hand sprayer. The application of 20 mM H2O2 amplified leaf number, tallness, stomatal conductance, and photosynthetic yield by 143, 24, 88, and 18%, respectively, over the control plant. A reduced transpiration rate and improved chlorophyll fluorescence were also noted in H2O2-treated plants. The treatment produced a greater amount of chlorophyll a, total ...

Environmentally friendly arbuscular mycorrhizal fungi (AMF) in the soil can alleviate host damage from abiotic stresses, but the underlying mechanisms are unclear. The objective of this study was to analyze the effects of an arbuscular mycorrhizal fungus, Paraglomus occultum, on plant growth, nitrogen balance index, and expressions of salt overly sensitive genes (SOSs), plasma membrane intrinsic protein genes (PIPs), and tonoplast intrinsic protein genes (TIPs) in leaves of tomato (Solanum lycopersicum L. var. Huapiqiu) seedlings grown in 0 and 150 mM NaCl stress. NaCl stress severely inhibited plant growth, but P. occultum inoculation significantly improved plant growth. NaCl stress also suppressed the chlorophyll index, accompanied by an increase in the flavonoid index, whereas inoculation with AMF significantly promoted the chlorophyll index as well as reduced the flavonoid index under NaCl conditions, thus leading to an increase in the nitrogen balance index in inoculated plants...

This research was carried out to examine the effects of Sargassum stolonifolium on reducing cadmium in Brassica chinensis L. tissue, its influential roles on physiological parameters and antioxidant mechanism in B. chinensis exposed to cadmium stress. Different levels of Cd (50 mg and 100 mg) with and without S. stolonifolium (25g, 50g and 100g) under five replications were explored in this study. Biomass, photosynthetic pigment, relative water content (RWC), malondialdehyde (MDA), hydrogen peroxide (H2O2), 2,2-diphenyl-1-picrylhydrazyl (DPPH), total antioxidant activity (TAA), non-protein thiol (NPT), protein thiol (PT), protein bound thiol, glutathione (GSH), phytochelatins, ascorbate peroxidase (APX), Catalase (CAT), superoxide dismutase (SOD) and guaiacol peroxidase (POD) were determined. The results revealed that Cd stress significantly (P < 0.05) reduced plant biomass and physiological attributes, and accumulated higher Cd concentrations in plant tissues with the increasing...

A field study was carried out to examine the effects of organic amendment on the morpho-physiology, growth indices, and fruiting of pumpkin (Cucurbita moschata) plants. The pumpkin seedlings were raised in polybags and treated without fertilizer (control), cow dung, goat dung, poultry dung, vermicompost, compost, and inorganic fertilizer (NPK). The results showed that poultry dung and cow dung treatments significantly increased the length of vine, leaf number, leaf area, and leaf dry weight of pumpkin plants. Poultry dung treatment increased the absolute growth rate (AGR), relative growth rate (RGR), leaf area index (LAI), leaf area ratio (LAR), leaf area duration (LAD), and fresh plant biomass by 345%, 287%, 770%, 384%, 415%, and 1139%, respectively over the control plants. Poultry dung treatment also increased the internode length and initiated flowers earlier than the control. Petiole length, stomatal conductance, and chlorophyll content were 5.59, 1.49, and 1.41 times higher wit...

The study was conducted to evaluate the effect of different concentration of gibberellic acid (GA3) on okra growth and development. The stem injection innovative method of application was used in this experiment rather than spray as common and traditional method. Stem injection method was applied on the stem of okra plant using GA3 at different concentrations. The higher concentrations (100 mg/l) of GA3 greatly increased the plant height compared to the control. GA3 application at 100 mg/l induced the highest value of stem girth over the control. The chlorophyll content in leaves was affected significantly by different concentrations of GA3. It was found that all concentrations of GA3 (25, 50, 100 and 200 mg/l) increased chlorophyll content per leaf by 37, 45, 60 and 55% compared to the control. The pod per plant, pod length, pod diameter, pod size, per pod weight and healthy seeds percentage per pod were significantly affected by different concentrations of GA3. The 100 and 200 mg/...

The study was conducted to evaluate the effect of different concentrations of indole 3-acetic acid (IAA) on the okra growth and seedless production. The micro syringe injection technology applied on the flower bud, ovary and shoot xylem was an innovative technique of growth regulator application (IAA) and used in this experiment rather than spray as common and traditional method. Flower bud injection technique was applied on the flower before flowering (Expt. 1), flower ovary injection technique was applied on the flower after anthesis of flower (Expt. 2) and shoot xylem injection technique was applied on the main shoot (stem) before flowering (vegetative stage) using IAA at 0, 25, 50, 100 and 200 mg/L concentrations (Expt. 3). The concentrations of 25, 50 and 100 mg/L IAA greatly exhibited higher pod setting percent compared with the 0 and 200 mg/L in the case of flower bud, ovary and shoot xylem injection. The higher pod length, diameter, weight, size, total soluble solids and vit...

A greenhouse study was conducted to evaluate the response of cherry tomato cultivar Dulcito RZ to different irrigation levels and fruit pruning treatments. Treatments were three irrigation levels [50, 75, and 100%, based on the crop Evapotranspiration (ETc)], and three fruit pruning treatments (6, 8, and 10 fruits truss -1 ). Results showed that the highest irrigation level (100% ETc) increased fruit weight and size, and total and marketable yield. However, water stress treatment (50% ETc) increased fruit quality traits (total soluble solids, titratable acidity, vitamin C, and total sugars). Plants pruned to 6 fruits truss -1 yielded a heavier and larger fruit size, while unpruned plants had smaller fruit size with a significant increase in total and marketable yield due to increased number of fruits plant -1 . The increased incidence of fruit cracking with lower fruit load (6 fruits truss -1 ) or with higher irrigation level (100% ETc) were related with the larger fruit size. The 5...

Mulching and irrigation water management is among the vital practices that are being applied in commercial vegetable production. White-on-black plastic mulch in combination with four irrigation levels (40, 60, 80 and 100% based on crop evapotranspiration (ETc)) was applied to assess growth and yield responses of two F1 muskmelon cultivars (‘Velta’ and ‘Parana’) under greenhouse conditions. Crop water productivity (water use efficiency, WUE and irrigation water use efficiency, IWUE) were also evaluated. Plastic mulch treatment resulted in higher plant height, leaf area, fruit number, early fruit yield, total yield and crop water productivity than non-mulch treatment. High and medium irrigation levels (100 and 80% ETc) enhanced plant height and leaf area and increased fruit number, early and total yield. On the other hand, low irrigation levels (40 and 60% ETc) decreased yield and increased WUE and IWUE. ‘Velta’ plants showed superior vegetative growth, higher crop yield, WUE and IWUE...

The peach industry faces serious economic losses because of the short “green” life of the fruit at postharvest. In the present study, we investigated the effects of putrescine (PUT) application on the quality characteristics, pattern of ripening, storage behaviour and shelf life of peach fruit during low-temperature storage. The aqueous solution of PUT (0, 1, 2 and 3 mM) was applied to the peach trees at three distinctive stages of fruit growth and development. The fruits, harvested at the commercial stage of maturity, were stored at 1 ± 1 °C and 90 ± 2% relative humidity for 6 weeks. The data for fruit firmness, total soluble solids (SSC), titratable acidity (TA), ascorbic acid (AsA) content, rate of ethylene production, chilling injury (CI) index and colour perception were collected at harvest and then on a weekly basis throughout the storage period. The results showed that spray application of PUT significantly reduced the incidence of CI and reduced the rates of fruit softening,...

The present study reports on the effect of humic and salicylic acids on the growth, yield, and fruit quality of three red sweet pepper (Capsicum annuum) cultivars: Barbero, Ferrari, and Imperio. The plants were grown in a greenhouse and the leaves were treated with humic or salicylic acids at 0, 0.5, 1.0, and 1.5 g·L−1 at 20, 40, and 60 days after transplanting. Foliar application of humic or salicylic acids significantly increased vegetative growth, fruit yield, and quality of the three cultivars as compared with the control plants. However, salicylic acid treatment proved more effective than humic acid treatment. Red sweet pepper plants of all three cultivars sprayed with 1.5 g·L−1 salicylic acid showed the greatest vegetative growth; fruit yield components, such as fruit number, diameter, and fresh and dry weights; and fruit quality traits, such as vitamin C content, total soluble solid content, titratable acidity, and total sugar content, than the plants in all other treatments....

Scarcity of water is one of the most serious concerns in plant biology with diverse implications at all the levels of molecular, biochemical, and physiological phenomena of plant growth, development, and consequently the productivity. Most of the strategies to induce or enhance drought tolerance in plants are unreasonably expensive and/or time-consuming. Some studies conducted in the recent past have shown that plant growth regulators (PGRs) may induce/improve physiological tolerance in plants to cope with adverse environmental conditions including drought. The present study was aimed at investigating the effects of foliar spray of GABA (0, 1, 2, and 4 mM) applied 20 days following the germination of seeds, on vegetative growth, morphological characteristics, integrity of cell-membrane, and the levels of photosynthetic pigments and enzymatic antioxidants in carrot cvs. Supertaj and Bharat, grown under 100% and 50% field capacity of soil moisture. The treated and untreated (control) ...

Studies were conducted to investigate the effects of plant growth regulators on okra growth, yield and quality development using different techniques of application in a commercial vegetable field in Banting, Selangor, Malaysia. The experimental design employed on the commercial field was a randomized complete block design (RCBD). The different growth hormones were applied directly, internally, to the selected parts of the okra plant. In the flower injection treatment, injection was applied on the okra flower using IAA at different concentrations. The pod set percentage, and length was maximal in the 25 mg/l IAA treatment compared to the control. Higher percentage of healthy seed per plant was also recorded using 25 mg/l IAA followed by control and 50 mg/l IAA. However, a high concentration of IAA (200 mg/l) inhibited seed production and brought about Stenospermocarpy which resulted in 100% aborted seeds. Total soluble solids (TSS) and vitamin C content in the pod markedly increased as a result of IAA application at all the different concentrations. The highest K+ content was found in 25 mg/l IAA treated plants. In addition, the iron (Fe) content increased significantly in IAA treatments at all concentrations compared to the control. The flower injection method using different NAA concentrations showed higher percentage of pod setting in the 25 mg/l NAA treatment compared to the higher NAA concentrations. Pod weight increased in 25; 50 and 100 mg/l NAA treatments compared to the control. Healthy seed percentage was maximal in 25 mg/l NAA treated flowers whereas 100 mg/l NAA treated flowers exhibited a lower percentage of healthy seeds, but a higher percentage of aborted seeds. Using different GA3 concentrations, the highest pod setting (100%) was obtained at 100 mg/l GA3. GA3 at 50, 100 and 200 mg/l produced a higher percentage of healthy seeds per pod than 25 mg/l GA3 and control. The highest TSS, vitamin C and K+ content was observed in the 100 mg/l GA3 treatment. With ovary injection, percentage of pod setting was maximal at 25 mg/l IAA and minimum at 100 mg/l IAA compared to the control. IAA at 25 and 50 mg/l concentrations increased pod diameter by 6-20% whilst 25 mg/l IAA was the best treatment for growth and pod parameters except for healthy seed production and Mg pod content. Ovary injection using different NAA concentrations produced higher pod set percentages (98.53 and 94.97%), TSS and vitamin C content at lower NAA concentrations (25 and 50 mg/l) compared to the control. Maximum healthy seed percentage per pod was recorded in the 25 mg/l of NAA treatment, while the highest aborted seed percentage was observed at 100 mg/l NAA. With regard to the application of different concentrations of GA3, highest pod setting occurred in the 25 and 50 mg/l GA3 treatment and the lowest was observed in 200 mg/l GA3 and the control. GA3 at 25 and 50 mg/l produced bigger pod size with higher pod weight than at other concentrations. Healthy seed percentage was highest at 50 mg/l GA3 and lowest at 200 mg/l GA3. In the stem injection method, IAA at 100 and 200 mg/l produced taller plants than, treatment at 25, 50 mg/l IAA and the control treatments, which meant that plants treated with 100 and 200 mg/l had the higher number of branches, leaves and pods than the other treatments. Chlorophyll content, quantum yield of chlorophyll fluorescence (Fv/Fm) and growth and pod parameters were not affected by the different concentrations of IAA. The tallest plant was obtained with the lowest concentration of NAA (25 mg/l) used compared to other treatments. It was observed that different concentrations of NAA injected into the stem did not affect growth and pod parameters. Application of 100 mg/l GA3 greatly increased plant height compared to the control. It was found that all concentrations of GA3 used increased chlorophyll content per leaf by 37, 45, 60 and 55% compared to the control. The pod number per plant, pod length, pod diameter, pod size, pod weight and percentage of healthy seeds per pod were significantly affected by the different concentrations of GA3. In the seed soaking method, the highest germination percentage and tallest stem were achieved with 25 mg/l IAA compared to the control. Chlorophyll content and the quantum yield of chlorophyll fluorescence (Fv/Fm) were higher in the 25 and 50 mg/l IAA treatments, compared to the control. Maximum healthy seed percentage was obtained with 25 mg/l IAA while the lowest was obtained in 200 mg/l IAA treatment. Likewise, 25 mg/l NAA gave the highest germination percentage (100%) compared to control (77.5%). Application 25 and 50 mg/l NAA brought about a highly significant effect on plant height compared to the control. Vitamin C and K+ were affected significantly by the different concentrations of NAA. The highest plant height was recorded in 200 mg/l GA3 (check this out?). The highest chlorophyll content and quantum yield of chlorophyll fluorescence (Fv/Fm) was found in…

Deficit irrigation (DI) is an optimization strategy that allows water stress to some extent during certain cropping stages or for the whole season without a significant reduction in yield. A greenhouse experiment was conducted during the growing seasons of 2009/2010 and 2010/2011 to study the effect of water quality and DI on growth, yield and water use efficiency (WUE) of tomato at different growth stages. Two different water qualities (saline and non-saline water with electrical conductivities (EC) 3.6 and 0.9 dSm-1, respectively) nine DI treatments and three irrigation treatments (100, 75 and 50% of Etc) were investigated in the experiment. Furthermore, DI at 75% and 50% of ETc during vegetative, reproductive, and fruiting stage were adopted. The result indicated that in general the irrigation with saline water decreased tomato fruits yield and WUE. Moreover, the negative effect of DI was more obvious when coupled with salt stress. Irrigation with saline water resulted in 22% and...

Abstract Poor red pigmentation in the berries of red table grapes has been a serious challenge to viticulture industry around the globe. During 2016 and 2017, the effects of spray applications of 100–400 mg L−1abscisic acid (ABA), alone or in combination with 125 or 250 ppm Ethrel® (Eth) applied at veraison, on color development, firmness and accumulation of dietary antioxidants in ‘Red Globe’ grape-berries, grown under the suboptimal conditions of Saudi Arabia, were investigated. At physiological maturity, the berries harvested from the grapevines treated with two spray applications of 200 mg L−1 ABA combined with 125 ppm of Eth at veraison, applied one week apart, exhibited significantly higher levels of total anthocyanins, phenolic and flavonoid contents in the skin compared to those harvested from the untreated (control) vines. At veraison, a brief exposure of grape-berries to ethylene seems to be required to initiate the process of anthocyanin biosynthesis. The firmness of the ABA-treated berries was slightly higher than those treated with Eth alone. In conclusion, two spray applications of ABA @ 200 mg L−1, combined with the substandard dose (125 ppm) of Eth at veraison, one week apart, substantially enhanced red pigmentation and increased the accumulation of dietary antioxidants in ‘Red Globe’ grape-berries grown under the non-conductive climatic conditions for anthocyanin biosynthesis. However, alternative management strategies need to be developed to maintain/improve the quality of grapes including berry firmness at commercial harvest and during storage.