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WENTY-FIVE bacterial isolates were isolated from mature …… compost and evaluated for their solubilization potential of insoluble zinc oxide and zinc carbonate. An efficient zinc-solubilizing bacterial isolate (Zn14) were chosen. Thereafter, some morphological and biochemical characteristics as well as 16S rRNA sequence indicated that the isolate belonged to Enterobacter cloacae. The effect of various carbon and nitrogen sources on the efficiency of Zn solubilization were investigated under shaking and static conditions. The selected bacterial strain could solubilize Zn compounds under a wide range of nutrient types. A pot experiment was conducted at Sakha Agricultural Research Station, Sakha, Kafrelsheikh, Egypt to study the efficiency of using Enterobacter cloacae as an in vivo Zn solubilizer either alone or with amended zinc compounds (ZnO and ZnCO 3) to the soil and its effect on growth parameters of Zea mays under sterile and non-sterile soil at the age of 30 and 60 days. There was a highly significant response for increased Zn uptake in all treatments compared to the control. The treatment with ZnO and E. cloacae was the more effective in terms of total chlorophyll plant dry weight compared to the control. To solve zinc nutrition problem using a biofertilizer, it is obvious that E. cloacae is capable of solubilizing insoluble zinc compounds by inoculation to increase crop growth and improve soil fertility.

The plant growth-promoting rhizobacteria (PGPR) application could reduce the use of synthetic fertilizers and increase the sustainability of crop production. Halophilic bacteria that have PGPR characteristics can be used in different environmental stresses. Two different strains isolated, purified, characterized as a PGPRs and phylogenetic identification using 16sRNA which was revealed to be closest matched at 99% with Bacillus halotolerans and Lelliottia amnigena. The isolates possessed plant growth promoting properties as exopolysaccharides (EPS) and indole acetic acid (IAA) production, Bacillus halotolerans had the ability to fix elemental nitrogen and the two strains have the ability to P-solubilization. Furthermore, the strains were evaluated in alleviation of different levels of salt stress on wheat plant at two experiments (Pots and a Field). Strains under study conditions significantly increased the plant height, straw dry weight (DW g plant -1 ), spike number, 1000 grain DW recorded 31.550 g with Lelliottia amnigena MSR-M49 compared to uninoculated and other strain in field, grain yield recorded 2.77 (ton fed -1 ) with Lelliottia amnigena as El-Akhdar et al.; JAMB, 20(1): 44-58, 2020; Article no.JAMB.54546 45 well as N% and protein content in grains recorded 1.213% and 6.916 respectively with inoculation with Lelliottia amnigena, also, spikes length, inoculated wheat show reduction in both proline accumulation in shoots and roots especially with Lelliottia amnigena recorded 2.79 (mg g -1 DW), inoculation significantly increased K + in root-shoot, K + /Na + in root-shoot and reduced Na + in rootshoot compared with control. This confirmed that this consortium could provide growers with a sustainable approach to reduce salt effect on wheat production. Original Research Article

O RGANIC farming is an advantageous agricultural system that enhances agro-ecosystem health, including biogeochemical cycles, biological activity and biodiversity in soils. In this regard, pots and lyzemeter experiments were conducted to evaluate eight compost preparations, and to investigate the combined effect of compost-Azotobacter chroococcum on growth and yield of wheat (Triticum aestivum L.) Cv. Misr 2 under different nitrogen levels (25, 50, 75 and 100% of full dose of nitrogen fertilizer). In pot experiment, application of compost treatment No. 8 (produced by mixture of rice straw, cattle dung and inoculated with Bacillus licheniformis and Bacillus sonorensis) attained the highest vegetative growth parameters at 46.3 cm plant height, 8.92 g plant fresh weight and 2.96 g dry weight of wheat plants at 30 days after sowing comparing with control. On the other hand, results in lyzemeter experiment showed that treatment No. 9 (50% of full dose of nitrogen fertilizer + 50% compost (pile 8) + inoculation with A. chroococcum), is the most effective treatment for enhancing growth dynamics, enzyme activity and microbial populations. Also, the highest data of biological yield, grain yield and straw yield were recorded 22.5, 8.64, and 13.92 ton ha -1 , compared to traditional N-fertilizer, respectively. Therefore, this study could establish the successive uses of cellulase producing microbes, B. licheniformis and B. sonorensis, and N 2 -fixing bacteria A. chroococcum as friendly microorganisms to improve wheat production.

IGHTEEN isolates of Azospirillum were collected from different sites at Kafrelsheikh Governorate. The isolates were cultivated on nitrogen-free malate (NFM) medium supplemented with different NaCl g l-1 concentrations (0, 0.7 and 1.5%) and tryptophan to study the salt tolerant in vitro and indole acetic acid production. Pots were used to evaluate the most salt-tolerant and efficient species and soils of this experiment had artificially salinized with different salinity levels. The most salt-tolerant A 10 and A 11 species were genetically identified by 16S rRNA sequencing and the results revealed to be closest matched at 98% A. lipoferum strains and selected to inoculate wheat plants. The investigated A. lipoferum species had variable divergence growth at different salinity levels. Actually, increased salinity had deleterious effect on IAA production. In addition, salinity had deleterious effect on dry weights of plants, number and dry weight of branches, total chlorophyll, sodium and potassium% with increasing salinity levels. But, inoculation with associative nitrogen fixation A. lipoferum isolates enhanced the previous parameters. Thus, inoculation with the salt-tolerant A.lipoferum isolates decreased the deleterious effect of salt stress on wheat plants.

Faba bean (Vicia faba L.) represents a major source of protein for animal and human nutrition, and provides several benefits such as improved soil quality. The Giza cultivar 87 (Vicia faba L.) was evaluated in three different salinity levels (6.9, 8.7 and 14.8 dSm-1) during two successive cropping seasons (2016-2017 and 2017-2018). The experiment was designed to analyze effect of soil salinity on nitrogen fixation, protein, chemical composition and crop productivity (for both grain and straw). Three phosphorus levels and inoculation with Rhizobium leguminosarum bv. viciae were investigated to improve the growth of Vicia faba L under these conditions. Soil salinity levels reduced the grain number and straw weight of plants. Moreover, yield reductions were associated with increasing soil salinity levels confirming salinity effects on faba bean productivity. Salinity induced a significant decreased in all plant growth parameters, plant chlorophyll and grains proteins, as well as increased Na% of faba bean plants. The plants treated with R. leguminosarum bv. viciae showed significant increase in growth traits such as plant length (%), plant fresh weight (%), protein, N-content and dry weight. On the other hand, the dual treatments with R. leguminosarum bv. viciae plus phosphorus gave a great results compared with inoculation or phosphorus alone. Symbiotic nitrogen fixation inoculation enhanced the growth and yield parameters.

To understand the genetic patterns of the physio-morphological traits for barley grain yield, six-generations (P 1 , P 2 , F 1 , F 2 , BC 1 , and BC 2 ) were used to determine the type of gene action in the four barley crosses. Grain yield showed a strong positive association (r = 0.83 and 1) with Grain Filling Rate in Giza121/RIL1 and Giza126/RIL2 crosses, respectively. The relationship between yield and earliness was not consistent with crosses and positive (r) values were quite low. It should be possible to select early-maturing and high-yielding segregates with high 100-kernel weight. The results indicated that the dominance effect [dd] was more important and greater than the additive effect [aa] and [ad] for most traits. Positive heterosis over the mid-and better-parent was quite similar for the most traits, except for heading and maturity dates, that showed negative heterotic effects. The inbreeding depression was high significant and positive for Grain Filling Rate, chlorophyll contents, Flag Leaf area and 100-kernel weight. On the other hand, it was a negatively significant for the earliness trait (HD, MD, and GFP). The lack of uniformity for estimates of inbreeding depression can be explained by environmental variation and to its influence on the type of gene action. Narrow-sense heritability ranged from 13.3% for Grain Filling Period in Giza12/RIL1 to 66.6% for heading dates in Giza121/RIL2 crosses. Genetic advance estimates were low due to lack of additive variance. The crosses Giza121/RIL1 and Giza126/RIL2 would be of interest in a breeding program, for improving characteristics of earliness, yield, and its components.Keywords: Hordeum vulgare L., type of gene action, heterosis, heritability IntroductionBarley (Hordeum vulgare L.) is a crop with great adaptive potential in many regions of the world. In areas which have only a brief rainy season, growers can obtain a harvest mainly because this crop has advantages in aspects such as salt tolerance, frost tolerance in the early period of development, drought tolerance, etc. Breeding for quantitative traits in early generations is impeded by several factors such as polygenic nature and low heritability of a trait (grain yield, the number of spikes per plant, etc.), linkage, non-additive gene effects and environmental effects (Harlan, 1976).In order to overcome these difficulties, it is necessary to get as much information as possible about the genetic structure of breeding population undergoing selection (Sharma et al., 2003). This means identifying the gene effects that control the inheritance of a trait of interest and contributing to the exploitable genetic variance of the population.Grain yield increase would be effectively rested with the basis of the capabilities of yield components and other closely associated traits. In cereal crops, the upper three leaves on the stem, especially the uppermost leaf, i.e., flag leaf, are the primary source of carbohydrate production. The flag leaf could contribute a large proportion of the carbohydrates...

The target of the present study is the selecting salt tolerant Rhizobium leguminosarum biovar viceae through isolated them from salt-affected soils of North Delta of Egypt, and evaluated for their efficiency and salt tolerance, thereafter, the best efficient and salt-tolerant selected isolates along with A. mycorrhizae were used to inoculate faba bean plants grown in pots to elucidate their effects on ameliorating salt effects on the plant. Rhizobial isolates varied in their tolerance to salinity. The isolates bringing from salt soils had more tolerance over those isolated from normal soil. The isolates of R2 and R6 were the superior. They confer the plants the highest nodules dry weight, plant dry weight and N-content. The plant exhibited the best growth and elements uptake (N, P and K-contents) when inoculated with the mixture of the tolerant rhizobia and mycorrhizae, especially R2+M treatment. Thus, we urged farmers to applying salt-tolerant inoculums in agricultural practices in order to increasing productivity of the crops under salinity condition. In addition, rather studies should be extended to explore the great benefits of microorganisms to alleviate different stresses on the crop.