Foliar application of silver nanoparticles mitigated nutritional and biochemical perturbations in chilli pepper fertigated with domestic wastewater.

Due to environmental pollution, crop growth and productivity are threatened at different levels. Recapitulation of changes in plant bodies due to water pollution and mitigating strategies reveal the need for précised actions to save crop losses. The present study was carried out to estimate modulations in growth, mineral homeostasis, and nutrient profile of fruits in Capsicum annum L. grown with three concentrations of wastewater (25, 50, 100%) and two levels of silver nanoparticles (40 and 80 mg/L AgNPs). It has been reported that ion accumulation patterns from wastewater clearly vary among crops. Our findings manifested that the application of AgNPs significantly improved the mineral ions in different plant tissues, that ultimately helped to improve growth. Highest improvements were recorded for root shoot P (316 and 197%) at T9 (80 mg/L AgNPs + normal water), while K (273 and 262%), Mg (638 and 916%), and Ca (148 and 273%), at T11 (80 mg/L AgNPs + 50% Wastewater), in comparison with control. Such reduction in elemental uptake that remain detrimental even at low concentrations positively correlates with growth and nutrition of Capsicum plants. Another facet of our observation is dose-dependent improvement in nutritive attributes of fruits i.e., crude fibers, proteins, and carbohydrates by AgNPs. T8 (40 mg/L AgNPs + 100% Wastewater), improved nutritional attributes such as P (55%), Mn (44%), Zn (38%), Carbohydrates (62%), Crude fat (38%), and Fibers (49%) as compared to control. Application of silver nanoparticles (AgNPs) combined with untreated wastewater (WW) reduced the hazards of contaminants in plants. The finding of the current study suggested that AgNPs are a cost-efficient and environment friendly material having the potential to mitigate harmful impacts of WW on plants.

Utilization of Genetic Resources, Genetic Diversity and Genetic Variability for Selecting New Restorer Lines of Rice (Oryza sativa L.).

Exploration of and understanding diversity and variability in genotypes of germplasm determines the success of rice improvement programs. One of the most important determinants of the success of breeding programs is genetic diversity and inheritance of traits. Genetic variability analysis helps breeders to determine the appropriate selection method and standards to be used to improve the preferred trait. The aim of this study was to estimate genetic components, heritability and to obtain information about genetic diversity using cluster analysis and principal component analysis. Twenty rice genotypes with three replicates in a randomized complete block design were analyzed at the Experimental Farm at Sakha Agricultural Research Station, Sakha, Kafr El-Sheikh, Egypt, during the period from 2017 to 2020. The results of the analysis of variance showed that highly significant variations were recorded between the studied genotypes for all traits. The genotypic coefficient of variation (GCV%) and phenotypic (PCV%) coefficient of variation were moderate for plant height, panicles/plant, panicle weight, spikelets/panicle, filled grains/panicle, grain yield/plant and amylose content percentage for the first-year, second-year and combined data. This indicates the existence of beneficial genetic variability that can be exploited to improve these traits. The broad-sense estimates of heritability were high and recorded values higher than 60% for all the studied traits for the two-year and combined data, except for hulling percentage. This indicates that the selection of traits that have high heritability and are less affected by the environment leads to an acceleration of the improvement of these traits. The results from the cluster analysis and principal component analysis revealed a high level of genotypic variation among the studied genotypes and genetic diversity between them. One of the most important outcomes of this study is the successful utilization of genetic resources (germplasm) from ancient varieties and lines of rice in selecting and identifying 17 new restoration lines of rice, which have various improvement purposes in rice and hybrid rice breeding programs.

Folic Acid Reinforces Maize Tolerance to Sodic-Alkaline Stress through Modulation of Growth, Biochemical and Molecular Mechanisms.

The mechanism by which folic acid (FA) or its derivatives (folates) mediates plant tolerance to sodic-alkaline stress has not been clarified in previous literature. To apply sodic-alkaline stress, maize seedlings were irrigated with 50 mM of a combined solution (1:1) of sodic-alkaline salts (NaHCO3 and Na2CO3; pH 9.7). Maize seedlings under stressed and non-stressed conditions were sprayed with folic acid (FA) at 0 (distilled water as control), 0.05, 0.1, and 0.2 mM. Under sodic-alkaline stress, FA applied at 0.2 mM significantly improved shoot fresh weight (95%), chlorophyll (Chl a (41%), Chl b (57%), and total Chl (42%)), and carotenoids (27%) compared to the untreated plants, while root fresh weight was not affected compared to the untreated plants. This improvement was associated with a significant enhancement in the cell-membrane stability index (CMSI), relative water content (RWC), free amino acids (FAA), proline, soluble sugars, K, and Ca. In contrast, Na, Na/K ratio, H2O2, malondialdehyde (MDA), and methylglycoxal (MG) were significantly decreased. Moreover, seedlings treated with FA demonstrated significantly higher activities of antioxidant enzymes including superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), and ascorbate peroxidase (APX) compared to the untreated plants. The molecular studies using RT-qPCR demonstrated that FA treatments, specifically at 0.2 mM, enhanced the K+/Na+ selectivity and the performance of photosynthesis under alkaline-stress conditions. These responses were observed through up-regulation of the expression of the high-affinity potassium-transporter protein (ZmHKT1), the major core protein of photosystem II (D2-Protein), and the activity of the first enzyme of carbon fixation cycle in C4 plants (PEP-case) by 74, 248, and 225% over the untreated plants, respectively. Conversely, there was a significant down-regulation in the expression ZmSOS1 and ZmNHX1 by 48.2 and 27.8%, respectively, compared to the untreated plants.

Blepharis saudensis (Acanthaceae), a new species from Saudi Arabia.

Blepharis saudensis, from small islands in the Red Sea of Jazan Provence, Saudi Arabia, is described as a new species and illustrated. This species differs from other known species in this genus by having a combination of long stems, oblong-lanceolate to linear leaves with entire margins and pubescence.

Assessment of ISSR based molecular genetic diversity of Hassawi rice in Saudi Arabia.

Inter simple sequence repeat (ISSR) analysis, using 14 primers was performed to estimate genetic diversity among 27 landraces of Hassawi rice growing in Al-Ahsa region of Saudi Arabia and deposited at King Abdulaziz City for Science and Technology with KACST IDs. The average polymorphism produced by 11 selected primers was more than 75%. The analysis of ISSR polymorphism divided the examined rice landraces into two groups; In one group (A), one accession (KACST 191) was clearly delimited as a distant landrace from other 12 landraces grouped in two clusters; cluster I of seven landraces of close geographic distributions; four of them grow at close geographic locations (KACST IDs 32, 183, 184, 185, 186, 187 and 188) and cluster II is comprised of five landraces KACST IDs (190, 308, 352, 353 and 355). In group B, the landraces were more closely related to each other as compared to the landraces of group A. In this group a small cluster of two landraces (KACST 305 & KACST 333) was clearly distant from a large group of three clusters comprised of landraces having KACST IDs 189 & 192, landraces 302, 306, 307, 308 & 310 and landraces with KACST IDs 334, 351, 354, 356 & 357 respectively. These results indicate that ISSR fingerprints are efficient in the identification and resolution of genetic diversity between the landraces of the Hassawi rice and will be an efficient method in the authentication of the rice germplasm in the gene bank of Saudi Arabia.