نوع مقاله : مقاله پژوهشی
نویسندگان
1 استادیار، گروه علوم باغبانی و مهندسی فضای سبز، دانشکده کشاورزی، دانشگاه بجنورد، بجنورد، ایران
2 دانشجوی کارشناسی، گروه علوم باغبانی و مهندسی فضای سبز، دانشکده کشاورزی شیروان، دانشگاه بجنورد، بجنورد، ایران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Objective
Salinity is one of the most important abiotic stresses limiting plant growth and shoot regeneration in in vitro culture. Desert willow (Chilopsis linearis) is a drought-tolerant tree species, but little information is available regarding its tolerance to salinity and the role of nano-chelate nitrogen in mitigating salt stress. The aim of this study was to investigate the intrinsic tolerance of desert willow to sodium chloride and the effect of nano-chelate nitrogen on growth traits, browning, and rooting under in vitro conditions.
Materials and Methods
This experiment was conducted as a factorial arrangement in a completely randomized design with two factors. The first factor was nitrogen source at two levels (10.3 mM ammonium nitrate and 2.6 mM nano-chelate nitrogen), and the second factor was sodium chloride at five levels (0, 50, 100, 150, and 200 mM). Shoot explants of desert willow were cultured on half-strength MS medium. After four weeks, traits including number of activated node, leaf number, percentage of stem browning, rooting percentage, root number, root length, and shoot fresh and dry weight were evaluated. Data were analyzed using SAS software, and means were compared using Duncan's multiple range test at a 5% probability level.
Results
The results showed that desert willow did not exhibit a significant reduction in leaf number, root number, and root length up to 100 mM sodium chloride, but at 150 and 200 mM concentrations, more than 89% reductionin these traits was observed. Nano-chelate nitrogen significantly increased activated node number by 63%, root number by 64%, and root length by 236% compared to ammonium nitrate. Furthermore, nano-chelate nitrogen reduced stem browning by approximately 88% at 50 and 100 mM salinity levels. The interaction effect of nano-chelate nitrogen × sodium chloride was significant for browning and rooting, such that at 200 mM salinity, nano-chelate nitrogen completely inhibited rooting.
Conclusion
Desert willow is a moderately salt--tolerant species to salinity, exhibiting relative tolerance up to 100 mM sodium chloride. Nano-chelate nitrogen is a superior nitrogen source compared to ammonium nitrate under in vitro conditions of this plant and can reduce salinity-induced browning and improve rooting under mild to moderate salinity. However, at very high salinity (200 mM), its application is not advisable.
کلیدواژهها [English]
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