Mode of gene action and heterosis for physiological, biochemical, and agronomic traits in some diverse rice genotypes under normal and drought conditions

Water scarcity is a crucial environmental stress that constrains rice growth and production. Thus, breeding for developing high-yielding and drought-tolerant rice genotypes is decisive in sustaining rice production and ensuring global food security, particularly under stress conditions. To this end, this study was conducted to evaluate the effects of water deficit on 31 genotypes of rice (seven lines, viz., Puebla, Hispagran, IET1444, WAB1573, Giza177, Sakha101, and Sakha105, and three testers, viz., Sakha106, Sakha107, and Sakha108) and their 21 crosses produced by line × tester mating design under normal and water deficit conditions; this was to estimate the combining ability, heterosis, and gene action for some traits of physiological, biochemical, and yield components. This study was performed during the summer seasons of 2017 and 2018. The results showed that water deficit significantly decreased relative water content, total chlorophyll content, grain yield, and several yield attributes. However, osmolyte (proline) content and antioxidant enzyme activities (CAT and APX) were significantly increased compared with the control condition. Significant mean squares were recorded for the genotypes and their partitions under control and stress conditions, except for total chlorophyll under normal irrigation. Significant differences were also detected among the lines, testers, and line × tester for all the studied traits under both irrigation conditions. The value of the σ²GCA variance was less than the value of the σ²SCA variance for all the studied traits. In addition, the dominance genetic variance (σ2D) was greater than the additive genetic variance (σ2A) in controlling the inheritance of all the studied traits under both irrigation conditions; this reveals that the non-additive gene effects played a significant role in the genetic expression of the studied traits. The two parental genotypes (Puebla and Hispagran) were identified as good combiners for most physiological and biochemical traits, earliness, shortness, grain yield, and 1,000-grains weight traits. Additionally, the cross combinations Puebla × Sakha107, Hispagran × Sakha108, and Giza177 × Sakha107 were the most promising. These results demonstrated the substantial and desirable specific combining ability effects on all the studied traits, which suggested that it could be considered for use in rice hybrid breeding programs

The Role of Carbon Nanotubes in Improving Drought Tolerance via Upregulation of the Physiological Processes of Peanut Plants Grown in Sandy Soils

Drought stress is an important challenge to global food security and agricultural output, and dramatic and rapid climate change has made the problem worse, causing unexpected impacts on the growth, development, and yield of different plants. Understanding the biochemical, ecological, and physiological reactions to these pressures is essential for improved management. Carbon materials’ impacts on plants subjected to different stresses are still poorly studied. Thus, this study was carried out investigate the feasibility of applying carbon nanotubes (CNTs) (0, 20, and 40 mg/L) as a foliar treatment for mitigating the effect of water stress (100%, 75%, and 50% irrigation water, IW) on peanut plants growing in sandy soil through assessments of growth and productivity and some physiological and biochemical measurements. Exposure of peanuts to decreased irrigation water led to significant decreases in growth, yield, photosynthetic pigments, indole acetic acid (IAA), and some nutritional components in peanut seeds, but increased levels of osmolytes such as total soluble carbohydrates (TSS) and proline, in addition to free amino acids and phenolics. However, foliar spraying with CNTs could ameliorate the impacts of decreased irrigation water on growth and production via enhancing the studied physiological parameters, such as photosynthetic pigments, IAA, osmolytes, and phenolics. Furthermore, the application of carbon nanotubes improved the nutrient contents, as expressed by the oil yield, protein yield, total carbohydrates, antioxidant activities (DPPH), B-carotene, lycopene, and flavonoids in peanut seeds, either under normal or water stress conditions. The higher level of CNTs (40 mg/L) was more effective than the lower one (20 mg/L) at increasing the above-mentioned parameters. In conclusion, foliar treatment with carbon nanotubes has the ability to enhance peanut drought tolerance and increase its growth and productivity under sandy soil conditions

Assessing Soil Quality, Wheat Crop Yield, and Water Productivity under Condition of Deficit Irrigation

Wheat is one of the most important cereal crops in Egypt and all over the world. Its productivity is adversely affected by drought due to deficient irrigation to provide nutrients required for plant growth. In a field experiment, silicon foliar applications at concentrations of 0, 200, and 400 mg L−1 were performed at different irrigation rates ranging from 1000 to 4000 m3 ha−1 to assess water irrigation productivity and wheat crop yield in a calcareous soil under arid climate conditions. Increased irrigation rates led to a significant increase in soil nutrient dynamics, as well as in the number and weight of grains per spike, leaf area index, grain yield, straw yield, and biological yield, with the exception of the weight of 1000 grains. Spraying with sodium silicate had a significant impact on grain yield and harvest index but did not significantly impact the other traits. Furthermore, the interaction between irrigation and silicate application rates showed significance only for grain yield, the number of spikes/m2, and the harvest index. Applying three times irrigation could produce the highest nutrient retention, wheat yield, and water irrigation productivity. No significance was observed between 3000 m3 ha−1 and 4000 m3 ha−1 irrigation, indicating a saving of 25% of applied irrigation water. It can be concluded that applying irrigation at 3000 m3 ha−1 could be a supplemental irrigation strategy. High wheat grain yield can be achieved under deficit irrigation (3000 m3 ha−1) on the northwestern coast of Egypt with an arid climate by spraying crops with sodium silicate at a rate of 400 mg L−1

Improvement of Selected Morphological, Physiological, and Biochemical Parameters of Roselle (Hibiscus sabdariffa L.) Grown under Different Salinity Levels Using Potassium Silicate and Aloe saponaria Extract

Two successive field trials were carried out at the experimental farm of the Agriculture Department of Fayoum University, Fayoum, Egypt, to investigate the sole or dual interaction effect of applying a foliar spray of Aloe saponaria extract (Ae) or potassium silicate (KSi) on reducing the stressful salinity impacts on the development, yield, and features of roselle (Hibiscus sabdariffa L.) plants. Both Ae or KSi were used at three rates: 0% (0 cm3 L−1), 0.5% (5 cm3 L−1), and 1% (10 cm3 L−1) and 0, 30, and 60 g L−1, respectively. Three rates of salinity, measured by the electrical conductivity of a saturated soil extract (ECe), were also used: normal soil (ECe < 4 dS/m) (S1); moderately-saline soil (ECe: 4–8 dS/m) (S2); and highly-saline soil (ECe: 8–16 dS/m) (S3). The lowest level of salinity yielded the highest levels of all traits except for pH, chloride, and sodium. Ae at 0.5% increased the values of total soluble sugars, total free amino acids, potassium, anthocyanin, a single-photon avalanche diode, stem diameter, fruit number, and fresh weight, whereas 1% of Ae resulted in the highest plant height, chlorophyll fluorescence (Fv/Fm), performance index, relative water content, membrane stability index, proline, total soluble sugars, and acidity. KSi either at 30 or 60 g L−1 greatly increased these abovementioned attributes. Fruit number and fruit fresh weight per plant also increased significantly with the combination of Ae at 1% and KSi at 30 g L−1 under normal soil conditions

Mitigating cold stress in rice: a study of genotype performance and sowing time

Abstract Rice (Oryza sativa L.) is an essential food for half of the global population and is vital in maintaining global food security. Climate change, increasing population and recent incident of COVID pandemic has generated financial burden and threaten the global food security. Due to theses factors rice cultivation also has to face significant challenges. frequent weather changes pose a considerable challenge to agricultural planning, which was previously relaying on consistent seasonal variations. In this context, rice cultivation is particularly sensitive to cold, where its development and productivity inhibited by low temperatures (< 18 °C). Developing rice varietes with low temprature tolerence and good yield potential is one of the major goals of current breeding efforts of plant scientists. For this purpose, short duration and early rice varieties are most favorable to avoid cold stress and yield more in less number of days. this study was designed to investigate the effect of low temperatures on different rice varieties. the study was designed to identify low temprature tolerent genotypes with early and regular cultivation. For this, thirty-four genotypes were evaluated in two gorwing seasons (2018–2019) with four different sowing times. Statistically sowing time showed significant interaction between all yield contributing parameters. The data indicate that exposure to low temperatures during the reproductive phase prolongs the maturation period of the crop, also length of the panicle and the fertility of the spikelets drops, resulting in a significant decrease in the production of sensitive varieties. Some varieties are more sensitive to cold stress compared to others. In the Egyptian context, Giza176, Sakha104, and Sakha107 are recommended for early cultivation, while the genotypes Giza 179, Sakha101, Sakha104, and GZ 9730-1-1-1-1 are indicated for the normal cultivation period. The Sakha104 variety is particularly notable, as it is recommended for both purposes. In addition, the data obtained in this study provide valuable information for selecting rice varieties suitable for double cropping in the North Delta of Egypt. This study also contributes to the existing literature, providing insights into the resilience of rice cultivation in the face of climate change

Germination, physio-anatomical behavior, and productivity of wheat plants irrigated with magnetically treated seawater

Salinity is an abiotic stress that reduces the seed germination and productivity of wheat. The objective of this study was to assess the impact of irrigation with magnetically treated seawater on the germination, growth, certain physiological and anatomical parameters, and production attributes of wheat (Triticum aestivum L.) cv. Sakha 93 plants. Experiments were conducted in the Experimental Farm of the Faculty of Agriculture, Menoufia University, Egypt, during two consecutive winter seasons. Pot experiments involved ten treatments with non-magnetized and magnetized water with various degrees of salinity. Plant samples were taken 95 days after sowing. Irrigation with magnetically treated seawater was found to have beneficial effects on plant growth, water relations, biochemical characteristics, and yield components compared with untreated plants. The germination of wheat seeds increased 13% when treated with magnetic seawater. On the yield scale, the spike length was increased by 40% in season one, and 82% in season two when compared to the control, while the weight of 100 grains increased by 148% and 171%, in each season, respectively, when treated with magnetic water. The anatomical leaf and stem parameters of the plants were markedly improved by watering with magnetically treated seawater at 10 dS m-1 compared to the control. However, the leaf water deficit, transpiration rate, and abscisic acid content in the plant shoots decreased significantly (p < 0.05). The use of magnetically treated seawater of up to 7.5 dS m-1, instead of tap water, is recommended due to benefits to germination and seedling parameters, growth, yield, and physiological, chemical, and anatomical characteristics. In conclusion, magnetic treatment of seawater improved germination performance, growth, and yield of wheat under saline conditions. Keywords: chemical constituents; growth; leaf blade and stem structure; magnetic field; seawater; water relations

Response of nine triticale genotypes to different salt concentrations at the germination and early seedling stages

Salinity stress poses a major challenge to agricultural productivity worldwide, and understanding their responses at the early growth stage is vital for devising strategies to cope with this stress. Therefore, to improve triticale productivity, this study investigated the salinity stress tolerance of different salt-tolerant triticale genotypes aiming to cultivate them on saline soils. To this end, salinity stress impacts on nine triticale genotypes, i.e., Zhongsi 1084, Gannong No. 2, Gannong No. 4, Shida No. 1, C6, C16, C23, C25 and C36 at germination and early seedling stages was evaluated. Each genotype was subjected to six treatments inducing control, 40, 80, 120, 160, and 200 mM NaCl treatments to study their effect on seedling and termination traits of the nine genotypes. Compared to the overall mean seedling vigor index, the seedling vigor index was higher in the genotypes Zhongsi 1084 and C6 (39% and 18.1%, respectively) and lower in Gannong No.2 (41%). Increasing NaCl concentrations negatively affected germination and seedling traits. Compared to other genotypes, Zhongsi 1084 had the highest mean germination rate, germination vigor index, germination percentage, mean daily germination and germination energy. It also showed the lowest relative salt injury. The relative salt injury was higher in the genotype Shida No. 1 than those in Gannong No. 2, Gannong No. 4, Shida No. 1, C16, and C36 genotypes. All genotypes exhibited desirable mean germination time except for line C6. High significant positive correlations were observed among germination rate, germination vigor index, germination percentage, mean daily germination, seedling vigor index, and root length. Principal component analysis (PCA) grouped the most desirable genotypes into two clusters. Our study determined salt stress tolerance of nine triticale genotypes at germination and early seedling stages. to select salt-tolerant genotypes that can be cultivated on saline soil or after salt irrigation

Effect of dietary supplementation of betaine and organic minerals on growth performance, serum biochemical parameters, nutrients digestibility, and growth-related genes in broilers under heat stress

Global warming and climate changes have a detrimental impact on poultry production, causing substantial economic losses. This study investigated the effects of incorporating dietary betaine (BT) and organic minerals (OMs) on broilers’ performance as well as their potential to mitigate the negative impacts of heat stress (HS). Six hundred 1-day-old Ross 308 chicks were randomly allocated to 12 experimental treatments with 5 replicates of 10 birds each (5 male + 5 female). The birds were provided with diets containing BT (0 and 2,000 ppm) and OMs (0, 250, and 500 ppm), either individually or in combination, under both thermoneutral and HS-inducing temperatures. The HS conditions involved exposing the birds to cyclic periods of elevated temperature (35°C ± 2°C) for 6 h daily, from 10:00 am to 4:00 pm, starting from d 10 and continuing until d 35. The exposure to HS deteriorated birds’ growth performance; however, dietary BT and OMs inclusion improved the growth performance parameters bringing them close to normal levels. Carcass traits were not affected by dietary supplementation of BT, OMs, HS, or their interaction. Interestingly, while HS led to increased (P < 0.05) levels of total cholesterol, LDL-cholesterol, and hepatic malondialdehyde (MDA), these adverse effects were mitigated (P < 0.05) by the addition of BT and OMs. Moreover, dietary BT supplementation led to elevated serum total protein and globulin concentrations. Cyclic HS did not alter Mn, Zn, and Cu contents in the pectoral muscle. However, the incorporation of OMs at both levels increased concentrations of these minerals. Notably, the combination of 500 ppm OMs and 2,000 ppm BT improved Mn, Zn, Cu, and Fe digestibility, which has been compromised under HS conditions. Cyclic HS upregulated gene expression of interleukin-1β, heat shock protein 70, and Toll-like receptor-4 while downregulated the expression of claudin-1, uncoupling protein, growth hormone receptor, superoxide dismutase 1, glutathione peroxidase 1 and insulin-like growth factor 1. The aforementioned gene expressions were reversed by the combination of higher dietary levels of BT and OMs. In conclusion, the dietary supplementation of 500 ppm OMs along with 2,000 ppm BT yielded significant improvements in growth performance and mineral digestibility among broiler chickens, regardless of thermal conditions. Moreover, this combination effectively restored the expression of growth-related genes even under heat-stress conditions

DataSheet_1_Foliar spray of silica improved water stress tolerance in rice (Oryza sativa L.) cultivars.pdf

Rice (Oryza sativa L.) is a major cereal crop and a staple food across the world, mainly in developing countries. Drought is one of the most important limiting factors for rice production, which negatively affects food security worldwide. Silica enhances antioxidant activity and reduces oxidative damage in plants. The current study evaluated the efficiency of foliar spray of silica in alleviating water stress of three rice cultivars (Giza178, Sakha102, and Sakha107). The seedlings of the three cultivars were foliar sprayed with 200 or 400 mg l-1 silica under well-watered [80% water holding capacity (WHC)] and drought-stressed (40% WHC)] conditions for two summer seasons of 2019 and 2020. The obtained results demonstrated that drought stress caused significant decreases in growth, yield, and physiological parameters but increases in biochemical parameters (except proline) of leaves in all rice cultivars compared to well-irrigated plants (control). The roots of drought-stressed seedlings exhibited smaller diameters, fewer numbers, and narrower areas of xylem vessels compared to those well-watered. Regardless of its concentration, the application of silica was found to increase the contents of photosynthetic pigments and proline. Water relation also increased in seedlings of the three tested rice cultivars that were treated with silica in comparison to their corresponding control cultivars when no silica was sprayed. Foliar application of 400 mg l-1 silica improved the physiological and biochemical parameters and plant growth. Overall, foliar application of silica proved to be beneficial for mitigating drought stress in the tested rice cultivars, among which Giza178 was the most drought-tolerant cultivar. The integration of silica in breeding programs is recommended to improve the quality of yield and to provide drought-tolerant rice cultivars under drought-stress conditions.</p