Charcoal rot disease, a root and stem disease caused by the soil-borne fungus Macrophomina phaseolina (Tassi) Goid., is a major biotic stress that limits sorghum productivity worldwide. Charcoal rot resistance-related parameters, e.g., pre-emergence damping-off%, post-emergence damping-off%, charcoal rot disease severity, and plant survival rates, were measured in a structured sorghum population consisting of 107 landraces. Analysis of variance of charcoal rot resistance-related parameters revealed significant variations in the response to M. phaseolina infection within evaluated accessions. Continuous phenotypic variations for resistance-related parameters were observed indicating a quantitative inheritance of resistance. The population was genotyped using 181 simple sequence repeat (SSR) markers. Association analysis identified 13 markers significantly associated with quantitative trait genes (QTLs) conferring resistance to charcoal rot disease with an R2 value ranging between 9.47 to 18.87%, nine of which are environment-specific loci. Several QTL-linked markers are significantly associated with more than one resistance-related parameter, suggesting that those QTLs might contain genes involved in the plant defense response. In silico analysis of four novel major QTLs identified 11 putative gene homologs that could be considered as candidate genes for resistance against charcoal rot disease. Cluster analysis using the genotypic data of 181 SSR markers from 107 sorghum accessions identified 12 main clusters. The results provide a basis for further functional characterization of charcoal rot disease resistance or defense genes in sorghum and for further dissection of their molecular mechanisms.

Charcoal rot disease, a root and stem disease caused by the soil-borne fungus Macrophomina phaseolina (Tassi) Goid., is a major biotic stress that limits sorghum productivity worldwide. Charcoal rot resistance-related parameters, e.g., pre-emergence damping-off%, post-emergence damping-off%, charcoal rot disease severity, and plant survival rates, were measured in a structured sorghum population consisting of 107 landraces. Analysis of variance of charcoal rot resistance-related parameters revealed significant variations in the response to M. phaseolina infection within evaluated accessions. Continuous phenotypic variations for resistance-related parameters were observed indicating a quantitative inheritance of resistance. The population was genotyped using 181 simple sequence repeat (SSR) markers. Association analysis identified 13 markers significantly associated with quantitative trait genes (QTLs) conferring resistance to charcoal rot disease with an R2 value ranging between 9.47 to 18.87%, nine of which are environment-specific loci. Several QTL-linked markers are significantly associated with more than one resistance-related parameter, suggesting that those QTLs might contain genes involved in the plant defense response. In silico analysis of four novel major QTLs identified 11 putative gene homologs that could be considered as candidate genes for resistance against charcoal rot disease. Cluster analysis using the genotypic data of 181 SSR markers from 107 sorghum accessions identified 12 main clusters. The results provide a basis for further functional characterization of charcoal rot disease resistance or defense genes in sorghum and for further dissection of their molecular mechanisms.

Mapping of quantitative trait genes (QTGs) associated with drought related traits is essential for improving drought tolerance in crop species. In silico identification of candidate genes relies on annotation of critical QTGs to a variety of web resource-based datasets. The barley reference sequence was employed to map QTGs significantly associated with the proline accumulation and osmotic potential. Annotation of the critical QTGs contigs to the NCBI protein database identified 72 gene orthologs located on chromosomes 1H, 2H, and 7H, from which seven genes were identified as candidates. Expression analysis of all seven candidate genes revealed differential expression pattern between plants grown under well-watered conditions and drought-stress. The results represent a successful and highly powerful implementation of genome-wide scanning approach based on in silico mapping of QTGs to identify gene clusters having a common transcript pattern with similar function.

Drought is the most important yield limiting abiotic stress worldwide and could have negative effects on food security. This study was conducted to map yield and yield-contributing trait QTLs under drought stress by association mapping, and to in silico identify drought responsive genes and assay their expression profile. Association analysis was conducted using 181 SSR markers and nine phenotypic traits collected from a structured sorghum population consisting of 96 accessions evaluated under optimum and drought stressed conditions at Assiut University Experimental Farm, Assiut, Egypt. Genomic regions associated with major drought tolerance QTLs were annotated with NCBI and sorghum databases to identify drought responsive genes, which were further transcriptionally analyzed. Significant differences between optimum irrigation and drought-stressed conditions were observed in all measured phenotypic traits. Association analysis revealed 93 marker-trait associations between 71 SSR markers and the nine phenotypic traits with an R2 value ranging from 6.56 to 42.64%. A high degree of linkage disequilibrium (>52%) was identified among markers on different chromosomes, suggesting epistatic interaction. BLASTP annotation of QTL genomic sequences identified 86 gene homologs, from which fifteen genes are drought responsive. All fifteen genes were differentially expressed in drought tolerant and susceptible accessions and their expression levels were highly induced in response to drought stress. The results provide a powerful approach coupling association and in silico analyses to identify gene clusters having a common expression profile with similar function, pointing to an evolutionary mechanism to initiate a quantitative drought stress tolerance mechanism.

Field experiment was conducted at Shandweel Agricultural Station, Sohag Governorate in Upper Egypt during 2015 and 2016 seasons to study the effect of using some simulative substances on growth and productivity of Egyptian cotton cultivar (Giza 90) under late plantings in Upper Egypt. The experimental design was a randomized complete block designee using split plot arrangement with four replications. The Main plots included two planting dates (early in 1st March and late in 1st April) and sub plots included simulative substances (mineral, organic and biotic ) application namely: Silicate 7.5 cm3/L, Lithovit (CO2) 5g/L, Humic acid 5cm3/L, Mix of organic acids (citric 500 ppm, ascorbic 300 ppm and salicylic 200 ppm), Potassiomage 1kg/fed. and Mycorrhizae 4cm3/L with control (untreated plants). The combined analysis between years was done. Obtained results revealed that: Years affected significantly all characters under this study due to the variation in total amount of heat units, which was higher in 2016 growing season than 2015 season, this led to significant increase in vegetative growth (plant height and no. of fruiting branches/plant) as well as its caused decrease in most studded traits. Early planting significantly increased no. of fruiting branches/plant, no. of open bolls /plant, boll weight, seed index, seed cotton yield/fed. and fiber quality compared with the late planting date. Simulative substances application affected significantly plant height, number of fruiting branches /plant, number of open bolls /plant, boll weight, seed index, seed cotton yield /fed. and fiber quality. Plants sprayed with Humic acid gave the highest averages of these traits followed by plants sprayed with Silicate then plants sprayed with Lithovit. The interactions between years × planting dates and years × simulative substances had a significant effect on growth, yield and fiber quality under this study. Moreover, the interaction between planting date × simulative substances had significant effect on growth, yield and fiber quality. Also, the interaction between years × planting dates × simulative substances had significant effect on growth, yield and fiber quality. Simulative substances (mineral, organic and biotic) application to plants under early and late planting date had positive effects on improving the performance of cotton plants, which increased plant growth and yield especially under late planting.

Field experiment was conducted at Shandweel Agricultural Station, Sohag Governorate in Upper Egypt during 2015 and 2016 seasons to study the effect of using some simulative substances on growth and productivity of Egyptian cotton cultivar (Giza 90) under late plantings in Upper Egypt. The experimental design was a randomized complete block designee using split plot arrangement with four replications. The Main plots included two planting dates (early in 1st March and late in 1st April) and sub plots included simulative substances (mineral, organic and biotic ) application namely: Silicate 7.5 cm3/L, Lithovit (CO2) 5g/L, Humic acid 5cm3/L, Mix of organic acids (citric 500 ppm, ascorbic 300 ppm and salicylic 200 ppm), Potassiomage 1kg/fed. and Mycorrhizae 4cm3/L with control (untreated plants). The combined analysis between years was done. Obtained results revealed that: Years affected significantly all characters under this study due to the variation in total amount of heat units, which was higher in 2016 growing season than 2015 season, this led to significant increase in vegetative growth (plant height and no. of fruiting branches/plant) as well as its caused decrease in most studded traits. Early planting significantly increased no. of fruiting branches/plant, no. of open bolls /plant, boll weight, seed index, seed cotton yield/fed. and fiber quality compared with the late planting date. Simulative substances application affected significantly plant height, number of fruiting branches /plant, number of open bolls /plant, boll weight, seed index, seed cotton yield /fed. and fiber quality. Plants sprayed with Humic acid gave the highest averages of these traits followed by plants sprayed with Silicate then plants sprayed with Lithovit. The interactions between years × planting dates and years × simulative substances had a significant effect on growth, yield and fiber quality under this study. Moreover, the interaction between planting date × simulative substances had significant effect on growth, yield and fiber quality. Also, the interaction between years × planting dates × simulative substances had significant effect on growth, yield and fiber quality. Simulative substances (mineral, organic and biotic) application to plants under early and late planting date had positive effects on improving the performance of cotton plants, which increased plant growth and yield especially under late planting.

Five fungal isolates were isolated from infected tomato seedlings showing damping-off which collected from several tomato nurseries of Assiut and New Valley Governorates, Egypt. These isolates were Rhizoctonia solani Kühn, Fusarium oxysporum f.sp. lycopersici Schlechtendahl, Fusarium semitectum Berk. & Rav., Setosphaeria rostrata Leonard and Alternaria alternata (Fries) Keisler. Also, tomato seed treatments with Humic acid, Algae (Kelpak), Silicon (Potassium silicate) and Fungicide Topsen M (positive control) significantly reduced the disease percentage and disease severity of damping-off on tomato seedlings compared with untreated infected plants. Topsen M treatment markedly and completely inhibited disease percentage of damping-off compared with other tested compounds. The most effective application of commercial compounds was find when tomato seeds were treat with Potassium silicate.

Five fungal isolates were isolated from infected tomato seedlings showing damping-off which collected from several tomato nurseries of Assiut and New Valley Governorates, Egypt. These isolates were Rhizoctonia solani Kühn, Fusarium oxysporum f.sp. lycopersici Schlechtendahl, Fusarium semitectum Berk. & Rav., Setosphaeria rostrata Leonard and Alternaria alternata (Fries) Keisler. Also, tomato seed treatments with Humic acid, Algae (Kelpak), Silicon (Potassium silicate) and Fungicide Topsen M (positive control) significantly reduced the disease percentage and disease severity of damping-off on tomato seedlings compared with untreated infected plants. Topsen M treatment markedly and completely inhibited disease percentage of damping-off compared with other tested compounds. The most effective application of commercial compounds was find when tomato seeds were treat with Potassium silicate.

Five fungal isolates were isolated from infected tomato seedlings showing damping-off which collected from several tomato nurseries of Assiut and New Valley Governorates, Egypt. These isolates were Rhizoctonia solani Kühn, Fusarium oxysporum f.sp. lycopersici Schlechtendahl, Fusarium semitectum Berk. & Rav., Setosphaeria rostrata Leonard and Alternaria alternata (Fries) Keisler. Also, tomato seed treatments with Humic acid, Algae (Kelpak), Silicon (Potassium silicate) and Fungicide Topsen M (positive control) significantly reduced the disease percentage and disease severity of damping-off on tomato seedlings compared with untreated infected plants. Topsen M treatment markedly and completely inhibited disease percentage of damping-off compared with other tested compounds. The most effective application of commercial compounds was find when tomato seeds were treat with Potassium silicate.

The use of organic manure is proposed to reduce the use of chemical fertilizers, as well as to add sulfur (S) into the soil so that the phosphate use efficiency may be improved by maize crop. This field experiment was conducted during 2014 at Assiut city, Assiut governorate, Egypt to study the effect of sulfur and farmyard manure (FYM) on phosphorus availability, grain yield and phosphorus use efficiency of corn (Zea mays L. cv Single Hybrid 10). Randomized complete block design was followed with three replications. Four treatments viz SP= superphosphate, SP+S = superphosphate +sulfur, SP+FYM = superphosphate +farmyard manure and SP+FYM+S = superphosphate + farmyard manure + sulfur were tested. The soil analysis after corn harvest showed that the Olsen P of the soil improved with applying sulfur or farmyard manure and their mixture in presence of superphosphate. Adding farmyard manure with superphosphate enhanced grain yield of corn plants by 44.6% as well as the application of superphosphate with farmyard manure and sulfur increased the grain yield by 44.2% compared to the SP. The results in this study showed that amending soil by farmyard manure and sulfur with superphosphate improved phosphorus use efficiency in comparison with superphosphate alone.