Exploring the diversity of endophytic fungi and screening for their pullulanase-producing capabilities

Background Pullulanases are the significant industrial group in the 13 glycosyl hydrolases category, known as the α-amylases family. There are very few reports on pullulanase from fungal sources. Based on the above research gap, the present study was undertaken to explore the endophytic fungi for their pullulanase-producing capabilities. Results A total of 126 endophytes were isolated from Tradescantia pallida, Zea mays, and Trifolium alexandrinum. Aspergillus, Penicillium, and Ganoderma species recovered highest from the stem of Tradescantia palida. Fusarium was dominant in the stem and leaf of Zea mays. Penicillium, Aspergillus, Ganoderma, Cladosporium, Fusarium, and Alternaria were recovered from the Trifolium alexandrium. The Shannon index in Tradescantia pallida was highest in leaves while in Zea mays and Trifolium alexandrinum, it is highest in the stem. The Simpson’s index is highest in the case of Zea mays stem and root. Species richness was indicated by Menhinick’s index, and it was found that this value was highest in the roots of Trifolium alexandrinum. As per our knowledge, no comparative data is available on the endophytic diversity of the above plants taken for the study. Out of 126 endophytes, only 2.38% produced pullulanase while 7.94% produced amylase. The recovery of pullulanase-producing endophytic fungi was very less. But the importance of pullulanase is high as compared to amylase because it has both α-1,6 and α-1,4 hydrolyzing ability. Therefore, the most promising isolates were identified by ITS sequence analysis. Based on spore chain morphology, isolates BHU-25 and BHU-30 were identified as Penicillium sp. and Aspergillus species, respectively. This is the first report of pullulanase from endophytic Aspergillus and Penicillium. Conclusion Endophytes Aspergillus sp. and Penicillium sp. produce pullulanase enzyme. This is the first report of pullulanase from endophytic Aspergillus and Penicillium.

Accumulation of Potentially Toxic Metals in Egyptian Alluvial Soils, Berseem Clover (Trifolium alexandrinum L.), and Groundwater after Long-Term Wastewater Irrigation

The reduced availability of water resources in Egypt has imposed the need to intensify the use of wastewater for crop irrigation in the alluvial soils of anthropogenic origin. Relevant effects can derive from contents of potentially toxic metals (PTMs) in supply resources soils, crops, and groundwater in these areas. For this reason the PTM content has to be monitored to evaluate and minimize health hazards. Therefore, in this context, two areas of the SE Nile Delta subjected to 25 year of wastewater irrigation, using agricultural drainage water (ADW) and mixed wastewater (MWW) were chosen and compared with a nearby site irrigated with Nile freshwater (NFW). At each of the three sites, ten samples of irrigation water, topsoil, berseem clover (Trifolium alexandrinum L.) plants, and seven groundwater samples were collected and analyzed for Cr, Co, Cu, Pb, Ni, and Zn. Results indicate that the total contents of Co, Cu, Ni, and Zn in soils collected from the three sampling sites and Pb in the MWW-irrigated soils were higher than their average natural contents in the earth’s crust, indicating potential risks. The DTPA-extractable contents of Cu in the three sites, in addition to Pb and Zn in the MWW-irrigated soils, exceeded the safe limits. The MWW-irrigated soils showed a considerable degree of metal contamination, while the NFW- and ADW-irrigated soils showed moderate and low levels of contamination, respectively. The contents of the six PTMs in the three sites showed low individual ecological risks, except for Pb in the MWW-irrigated soils that showed a moderate risk; however, the overall ecological risk remained low in all samples. The values of Co, Cu, and Ni in berseem shoot in addition to Pb from the MWW-irrigated soils were over the maximum permissible levels for animal feeding. Values of root-to-shoot translocation factor were lower than 1.0 for Cr, Co and Ni but higher than 1.0 for Cu, Pb, and Zn. Berssem plant is a good candidate for phytofiltration of Cr, Co and Ni, while for extracting Cu, Pb and Zn from polluted soils. The groundwater samples collected from the three sampling sites showed lower metal concentrations than the safe limits for drinking standards. Further remediation studies should be taken into account to alleviate potential environmental and health-related risks when using supply resources different from freshwater.

Effect of Indigenous Bee Attractants on Qualitative and Quantitative Parameters of Egyptian Clover, Trifolium alexandrinum L.

Background: Egyptian clover (Trifolium alexandrinum L.) is one of the most important annual, winter, multi-cut fodder legumes grown in northern India. Many a times, poor activity of pollinators cited for lower seed production in berseem. Therefore, an appropriate local food-based bee attractants need to be identified and their effectiveness in enhancing berseem seed yield needs to be assessed. Methods: The experiment was conducted to evaluate the significance of bee visit on yield parameters of berseem. In addition, the effect of attractant (jaggery and sugar at 10%) in enticing honey bees towards the berseem flower was evaluated at ICAR- IGFRI, Jhansi during 2017 and 2018. Result: Both the attractants (jaggery and sugar at 10%) are equally effective in drawing the Apis dorsata towards berseem and higher bee visits (8.75 and 8.54/m2/5 min) were recorded one hour after application. Maximum seed setting percentage was recorded in plots sprayed with jaggery (83.53) followed by sugar solution (82.58), which is significantly superior over farmers practice i.e. crop left for open pollination (74.86). Maximum seed yield was obtained from plots sprayed with jaggery solution (8.15 q/ ha). The bee visit had significant positive effect on seed yield (0.685*) and 1000 seed weight (0.671*).

The Effects of Using Sulfur and Organic Bedding on the Content of Macro-and Micronutrients and Biologically Active Substances in Winter Garlic Bulbs

Sulfur (S) directly influences the proper development, yield, and biological value of Allium sativum. The sulfuric forms of S are easily leached from the soil due to poor sorption. In this context, we looked at to what extent application of S and biomass of catch crops (CCs) left until spring would cause an increase in the yield; we also looked at the macro- and micronutrient content of garlic plants. The experimental factors included applications of 0 and 20 kg ha−1 S to CCs consisting of Trifolium alexandrinum, Raphamus sativus var. oleiformis, Fagopyrum esculentum, Sinapis alba, and control. The bulbs contained more dry matter and macro- and micronutrients (N, P, K, S, Zn, and Fe) than those without S. Garlic plants cultivated with S accumulated more glutathione and total phenolic acids (TPA), and the extracts showed greater antioxidant activity (AA) than those cultivated without S. In 2019 and 2020, the cultivation of winter garlic with S, in combination with clover contributed to an increase in the content of dry matter, S, TPA, AA in bulbs. In the cultivation with fodder radish garlic plants accumulated more nitrogen (N), S, TPA, AA and glutathione in bulbs. In those cultivated with buckwheat, garlic contained more TPA, AA, glutathione, and with mustard more TPA and AA. However, further research is needed to select the species of CC and to determine the S dose to be applied in the effective biofortification of garlic in a sustainable agriculture system.

GENOTYPIC VARIATIONS IN SOME EGYPTIAN CLOVER (TRIFOLIUM ALEXANDRINUM L.) VARIETIES FOR FORAGE YIELD

The recent study’s objective was to detect variability in Egyptian multi-cut barseem genotypes via studying ten different commercial varieties regarding forage yield production during two successive winter seasons (2018/19 and 2019/20). These varieties, namely; Hartuor, Narmar, Sinai 2, Giza 6, Helaly, Gemiza, Serw1, Sakha 4, Khadrawy and Meskawi. Four cuttings were taken in each season. The analysis of variance in each season revealed that the mean squares due to berseem genotypes were significant for all studied traits. A wide range of variation was observed for plant height traits). Berseem varieties had fresh seasonal yield ranging from 114.70 to 137.72 and averaging 125.20 ton acre-1 in the first season. In the second season, the genotypes had a mean seasonal new yield of 146.89 with a range of 120.26 to 162.07 ton acre-1. Seasonal forage dry yield of the varieties ranged from 20.72 to 26.53 with a grand mean of 24.31 ton acre-1 in the first season, and it went from 25.10 to 29.84 with a great standard of 28.65 ton acre-1 in the 2nd season. Based on per se performance, the variety Khadrawy was identified for total fresh and dry forage yields. The values of PCV for different characters were higher than corresponding GCV values. Estimates of heritability were high for plant height at 3rd cut in the two seasons, plant height at the 1st and 2nd cuts, and seasonal dry yield in the second season. High heritability values coupled with high genetic advance were recorded for plant height at 2nd and 3rd cut in the two seasons, at 4th cut in the first season, and 1st cut in the second season. Genetic advance as percent of the mean (GAM) was found to be the highest for plant height at 1st cut in the second season (21.78 %) followed by seasonal dry yield in 2nd season (16.07 %).

Physicochemical characterization of agricultural run-off and groundwater inoculated by Trichoderma asperellum and its effect on anti-oxidative enzymes production by irrigated Trifolium alexandrinum L.

Water safety and security has become a great problem in recent years, as the shortage of water resources in most countries is becoming an increasingly serious issue. Therefore, searching for new water sources or treating contaminated water has become a major requirement to covering the shortage of fresh water. The current study evaluated the impact of Trichoderma asperellum on the physicochemical characterization of agricultural run-off (AR) compared with groundwater (GW). Chemical oxygen demand (COD), biological oxygen demand (BOD5), ammonia, total nitrogen (TN), and total dissolved salts (TDS) of AR were higher than that of GW with 90, 90.2, 91.9, 78, and 61.6%, respectively. The addition of T. asperellum to AR caused the COD, BOD5, ammonia, TN, and TDS to decrease 47.2, 39.2, 16.2, 12.9, and 4.8%, respectively. Contents of metals in AR or GW were decreased by T. asperellum. Microbial analysis of soil irrigated by AR in contrast to irrigated by GW showed the presence of a high number of bacteria (32 × 106 CFU), actinomycetes (18 × 104 CFU), and fungi (13 × 104 CFU). Trifolium alexandrinum growth and its antioxidant enzymes activities (catalase, superoxide dismutase, and ascorbate peroxidase) were enhanced by AR inoculated by T. asperellum compared with un-inoculated AR or GW.