نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشجوی کارشناسیارشد، گروه تولید و ژنتیک گیاهی، دانشکده کشاورزی، دانشگاه شهید باهنر کرمان، کرمان، ایران
2 استاد، گروه تولید و ژنتیک گیاهی، دانشکده کشاورزی، دانشگاه شهید باهنر کرمان، کرمان، ایران
3 موسسه تحقیقات ثبت و گواهی بذر و نهال، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرمان، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
The rising demand from associated industries, coupled with the restricted availability of licorice (Glycyrrhiza glabra L.), an important traditional medicinal plant, has resulted in overharvesting from the natural habitats. To mitigate this overharvesting, the continuous cultivation of this plant should be taken into account (Hayashi and Sudo, 2009). Considering the importance of turning to licorice cultivation to reduce the destruction of the natural habitats of this plant and the essential influence of the soil's physical and biological properties on this process, the application of organic inputs along with growth-promoting microorganisms can improve soil conditions, creates a more favorable environment for root development, which is the economically valuable part of the plant, while promoting sustainable land use. Plant growth-promoting bacteria significantly enhance soil biological conditions, promote plant growth, and protect plants against diseases and abiotic stresses. Acting as biostimulants, such bacteria stimulate various processes that enhance rhizosphere conditions and boost nutrient absorption in plants, thereby improving both the quantity and quality of the product (Emmanuel and Babalola, 2020). Biochar is a solid by-product generated from the decomposition of biomass derived from agroforestry plants, plant residues, or sewage sludge through pyrolysis at elevated temperatures under limited or absent oxygen conditions. Numerous studies have demonstrated the beneficial effects of biochar on soil cation exchange capacity, water retention capacity, and the enhancement of soil organic matter content. Furthermore, biochar is crucial for plant growth and nutrient availability (Rafael et al., 2019). The objective of this research was to examine the impact of biochar application integrated with inoculation with different growth-promoting bacteria on growth and yield of licorice.
Materials and Methods
The study was designed as a factorial experiment within a completely randomized framework, comprising 16 treatment combinations replicated three times in the research greenhouse of Shahid Bahonar University of Kerman during the 2024 growing season. The factors analyzed included the application of biochar at two levels: no application and application at 5% by weight of the soil applied. Additionally, three types of bacteria were used for inoculation: Bacillus subtilis (Bs), Pseudomonas chloraphis (Pc), and Pseudomonas putida (Pp). The inoculation treatments were categorized into eight different combinations, which included control (without bacterial inoculation), individual applications of each bacterial type (Bs, Pc, and Pp), dual applications (Pp+Pc, Pp+Bs, and Pc+Bs), and a combined application of all three bacteria (Pp+Pc+Bs). After the growth period, seedling emergence rate, plant height and root length, leaf number, leaf area, root volume, root and shoot dry weight, and bacterial inoculation effect were evaluated.
Results and Discussion
The findings indicated that the application of biochar significantly (P<0.01) influenced growth and the characteristics assessed. Furthermore, inoculation with Bs and the combined application of all three bacteria under biochar application, as well as inoculation with Pp in both biochar-applied and unapplied conditions, resulted in an increase in the number of leaves and leaf area by 115 and 139 %, respectively, subsequently enhancing the shoot dry weight by 141%. Additionally, inoculation with Bs, Pp+Bs, and the combined application of all three bacteria under biochar conditions, as well as Pp inoculation in both biochar treatments, improved root characteristics, leading to increased fresh and dry root weight by 300-400%. However, the application of Pc bacteria did not significantly affect root growth or weight. The findings of this research also indicated that incorporating biochar into the soil by influencing the vegetative growth and root weight of the licorice, enhanced the bacterial inoculation effect (BIE). Additionally, the results revealed varying efficiencies of the assessed bacteria on the growth and yield of licorice roots. Specifically, inoculation with Bs in combination with biochar yielded the most favorable outcomes. Conversely, Pp demonstrated a notable impact on the growth and root weight of licorice, regardless of whether biochar was applied or not. Furthermore, BIE results revealed that Bs exhibited negative efficiency in the absence of biochar. In contrast, Pp displayed positive efficiency under both biochar application and non-application conditions, resulting in increased root production. On the other hand, inoculation with Pc did not significantly affect root growth and production, and the application of biochar did not enhance its efficiency.
Conclusions
The results demonstrated that biochar enhanced the of bacterial inoculation effect across all treatments, with the exception of Pc. According to these results, the application of Bs and its combination with other bacteria under biochar application conditions and the application of Pp under both biochar application and non-application conditions are recommended for optimal growth of licorice.
کلیدواژهها [English]
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