Potatoes require high amounts of potassium (K) and nitrogen (N) fertilizers for optimum growth, production and tuber quality. Farmers and farming industries under the arid conditions and sandy soils of Saudi Arabia are applying K and N fertilizers to potatoes without attention to plant requirements. Therefore, five levels of potassium fertilizer were studied on agronomic performance, tuber quality and total yield of potatoes grown on a sandy soil in the arid environment of Central Saudi Arabia. Also, the effect of four levels of nitrogen fertilizer with different splitting methods on vegetative and tuber yields of potato were studied. The field experiments were carried out during 2002 and 2003 autumn seasons at the Experimental Farm of College of Agric. &Vet. Med., Al-Qassim University. Results reveled that increasing potassium sulfate rates resulted in a significant increase (p>0.05) in plant height, leaf area, chlorophyll concentration, specific gravity, K concentration and carbohydrate content. Marketable tuber yield was also significantly improved with increasing K rates. Also, the application of 300 kg Nha-1 split in three equal doses gave the highest percentage of soil coverage and marketable tuber yield. Under the conditions of this experiment, it is concluded that K and N is needed by potatoes for economic yield. The recommended rate for Al-Qassim and similar regions is 450 kg ha-1 potassium sulfate and 300 kg Nha-1 split in three equal doses which resulted in the highest potatoes yield.

The present study was conducted to evaluate the genetic diversity and relationships of 5 Saudi native chicken populations and a White Leghorn (L) strain as an exotic breed, using 25 microsatellite markers. According to morphological appearance and plumage color and pattern, they were classified into black (BL), black-barred (BR), dark brown (DB), light brown (LB), and gray (G) breeds. Twenty-five microsatellite markers were chosen based on the degree of polymorphism reported in the previous literature. The results revealed that all studied markers exhibited a varied percentage of polymorphism among native chicken populations. However, there were 81 polymorphic loci out of 109 loci. Based on cluster analysis, 3 main clusters of chicken populations were identified. Two clusters comprised native chicken breeds, while the L strain set the third one. Higher similarity was found between either black and gray populations (BL and G) or brown populations (LB and DB). They had a closer relationship to each other. Genetic distance between each couple was 0.11 and 0.12, respectively. The productive results revealed that the black breed had significantly (P < 0.0001) lighter body weight at sexual maturity compared to the other breeds. There was no significant difference between light and dark brown breeds for most productive traits. The genetic diversity we found among Saudi chicken populations may be of interest for improving productive performance and adaptability.

High temperature is a major environmental stress that devastatingly affects wheat production. Thenceforth, developing heat-tolerant and high-yielding wheat genotypes has become more critical to sustaining wheat production particularly under abrupt climate change and fast-growing global population. The present study aimed to evaluate parental genotypes and their cross combinations under normal and heat stress conditions, exploring their diversity based on dehydration-responsive element-binding 2 gene (DREB, stress tolerance gene in response to abiotic stress) in parental genotypes, and determining gene action controlling yield traits through half-diallel analysis. Six diverse bread wheat genotypes (local and exotic) and their 15 F1 hybrids were evaluated at two different locations under timely and late sowing dates. Sowing date, location, genotype, and their interactions significantly impacted the studied traits; days to heading, chlorophyll content, plant height, grain yield, and its attributes. Cluster analysis classified the parents and their crosses into four groups varying from heat-tolerant to heat-sensitive based on heat tolerance indices. The parental genotypes P2 and P4 were identified as an excellent source of beneficial alleles for earliness and high yielding under heat stress. This was corroborated by DNA sequence analysis of DREB transcription factors. They were the highest homologies for dehydrin gene sequence with heat-tolerant wheat species. The hybrid combinations of P1 × P5, P1 × P6, P2 × P4, and P3 × P5 were detected to be good specific combiners for grain yield and its attributes under heat stress conditions. These designated genotypes could be used in wheat breeding for developing heat-tolerant and climate-resilient cultivars. The non-additive genetic variances were preponderant over additive genetic variances for grain yield and most traits under both sowing dates. The narrow-sense heritability ranged from low to moderate for most traits. Strong positive associations were detected between grain yield and each of chlorophyll content, plant height, number of grains/spike, and thousand-grain weights, which suggest their importance for indirect selection under heat stress, especially in early generations, due to the effortlessness of their measurement.

Seeds from six selected jojoba genotypes were used in this study. Seed samples were analyzed for oil, protein, total carbohydrate, and simmondsin contents. The genetic relationships among jojoba genotypes were also determined. Highly significant differences among the genotypes were found for oil, protein, total carbohydrate and simmondsin contents. Genotype MD 8 recorded the highest oil content (54.95%), whereas genotype HD 6 had the lowest oil content (47.17%). However, the highest protein content (16.98%) and the highest carbohydrate value (33.97%) were found in genotype HB 6, which differed significantly from all the other genotypes. The significant variations in the studied characteristics observed among the genotypes might reflect, in part, their different genetic backgrounds. The inter-simple sequence repeat ISSR-derived data were evaluated to calculate the genetic similarity (ISSR-GS). The genetic similarity coefficient varied between 0.60 and 0.90. Cluster analysis was conducted to generate a dendogram to elucidate the relationships among jojoba genotypes. The dendogram generated using pooled ISSR data divided the jojoba genotypes into two main clusters. Genotypes HB8 and MD8 were found in the same sub-cluster using ISSR primers. These genotypes also had almost similar values for most chemical traits.

Wheat is an important cereal crop, and its significance is more due to compete for dietary products in the world. Many constraints facing by the wheat crop due to environmental hazardous, biotic, abiotic stress and heavy matters factors, as a result, decrease the yield. Understanding the molecular mechanism related to these factors is significant to figure out genes regulate under specific conditions. Classical breeding using hybridization has been used to increase the yield but not prospered at the desired level. With the development of newly emerging technologies in biological sciences i.e., marker assisted breeding (MAB), QTLs mapping, mutation breeding, proteomics, metabolomics, next-generation sequencing (NGS), RNA_sequencing, transcriptomics, differential expression genes (DEGs), computational resources and genome editing techniques i.e. (CRISPR cas9; Cas13) advances in the field of omics. Application of new breeding technologies develops huge data; considerable development is needed in bioinformatics science to interpret the data. However, combined omics application to address physiological questions linked with genetics is still a challenge. Moreover, viroid discovery opens the new direction for research, economics, and target specification. Comparative genomics important to figure gene of interest processes are further discussed about considering the identification of genes, genomic loci, and biochemical pathways linked with stress resilience in wheat. Furthermore, this review extensively discussed the omics approaches and their effective use. Integrated plant omics technologies have been used viroid genomes associated with CRISPR and CRISPR-associated Cas13a proteins system used for engineering of viroid interference along with high-performance multidimensional phenotyping as a significant limiting factor for increasing stress resistance in wheat.

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Red palm weevil (RPW), Rhynchophorus ferrugineus (Olivier) (Coleoptera, Curculionidae), is a devastating invasive pest, that invaded Saudi Arabia's date palms in 1987. Evaluation of the infestations and the efficacy of both preventative and control treatments have been studied from 2015- 2020 in Qassim. The results indicated that the number of infested date palms varied according to the years and locations. The infested date palm trees percentage was relatively high in 2016 (2.24%) and 2017 (3.19%), then gradually decreased to reach its lowest in 2020 (0.73%) due to the management protocol applied by the Ministry of Environment, Water, and Agriculture. Furthermore, the infested palm trees' percentage varied among the eight study locations, reaching the highest percentage in location G (SA7) with a general average of 4.31%. While in the other locations, the general infested percentage average was very low when compared to location G (SA7) with 1.21 and 0.47% in locations A (SA1) and H (SA8), respectively. The effectiveness of control methods increased sharply from 52.141% in 2015 to 90.0% in 2020 with a general average of 72.73%. The quarantine and management protocols of R. ferruginous applied in Qassim decreased the number of palm infestations. Contrary, the intensive use of insecticide in the last two decades promoted genetic mutations within the Rhynchophorus, which led to the emergence of a new species R. bilineatus. This leads to increase pesticide pollution, and control costs and the insect becomes more resistant to pesticides.