تاثیر پرایمینگ بذر بر جوانه‌زنی، ماده‌خشک‌کل و برخی صفات فیزیولوژیک دو گونه گیاه خارشتر (alhagi maurorum esfahan ecotype و a. graecorum khuzestan ecotype) تحت شرایط آب شور

به‌منظور بررسی سطوح مختلف پرایمینگ و شوری بر جوانه زنی، ماده خشک تولیدی و برخی پاسخ های فیزیولوژیک گیاه خارشتر دو آزمایش مجزا در آزمایشگاه و گلدانی در شرایط مزرعه به صورت اسپلیت فاکتوریل در قالب طرح بلوک های کامل تصادفی شامل سطوح مختلف شوری (شاهد از منبع آب شهری با هدایت الکتریکی 0.96 دسی‌زیمنس بر متر، 8 و 16 دسی زیمنس بر متر با استفاده از آب خلیج فارس) به عنوان عامل اصلی و روش های مختلف پرایمینگ بذر [بدون پرایمینگ، هیدروپرایمینگ، پرایمینگ جیبرلین (هورمون جیبرلین 50 پی پی ام) و هیدروپرایمینگ + پرایمینگ جیبرلین] و گونه های (alhagi maurorum esfahan ecotype و a. graecorum khuzestan ecotype) به عنوان عامل های فرعی در چهار تکرار در نظر گرفته شد. نتایج نشان دهنده تاثیر معنی دار برهمکنش شوری × پرایمینگ × گونه بر تمام صفات موردمطالعه به جز شدت تعرق و محتوی سدیم و پتاسیم اندام هوایی بود. در مورد شدت تعرق نیز تنها اثرات اصلی شوری و پرایمینگ معنی دار بود. نتایج مقایسه میانگین برهمکنش سه گانه نشان داد بیشترین مقدار صفات درصد جوانه زنی، ماده خشک کل، سرعت فتوسنتز، میزان co2 زیر اتاقک روزنه، کارایی مصرف آب فتوسنتزی و تعداد برگ در گونه alhagi graecorum khuzestan ecotype در شرایط شاهد بدون تنش شوری و هیدروپرایمینگ + پرایمینگ جیبرلین (به ترتیب با 29.1، 52.1، 26.8، 98.7، 15.6 و 38.8 درصد افزایش نسبت به تیمار بدون پرایمینگ و عدم اعمال تنش شوری در همین گونه) حاصل شد. بالاترین میزان هدایت مزوفیلی نیز در گونه alhagi graecorum khuzestan ecotype و تیمار بدون پرایمینگ در شرایط ds.m-1 8 اعمال تنش شوری (با میانگین mmol co2.m-2.s-1 0.492) مشاهده گردید. حال به منظور کشت و اصلاح اراضی شور حاشیه سواحل و نیز احیای مراتع کشور، گونه alhagi graecorum khuzestan ecotype تحت تیمار توام هیدروپرایمینگ (خوابانیدن بذرها به مدت دو روز در آب مقطر) و پرایمینگ جیبرلین نسبت به دیگر سطوح تیماری خوش آتیه تر به نظر می رسد.

effect of seed priming on germination, total dry matter and some physiological traits in two alhagi species (alhagi maurorum esfahan ecotype and a. graecorum khuzestan ecotype) under saline conditions

introductionthe researchers have been forcing to investigate and find an edible alternative high forage quality plant that has a well-tolerated instinct against adverse environmental conditions. alhagi, a genus of fabaceae is one of the most important halophyte plants in the world, as an industrial forage product used in the near future, medicinal production and pharmaceutical use. there are many reasonable that alhagi plants productivity and satisfactory yield requires good seed germination and seedling establishment. generally, germination and seedling establishment is the most decisive stage of alhagi plants life cycle to environmental stress. moderate to severe salinity stress is main abiotic causes of alhagi plants productivity loss at the seedling growth stage. high accumulation of na+ and cl- ions cause various negative influences that impact alhagi production, such as delays in the response of the plant to environmental conditions, retardation of germination, growth and development, inhibition of enzymatic activities and accumulation of some compatible osmolyte. in addition, to the salinity stress, the seed germination, seedling establishment and total dry matter production in alhagi plants occurs depends on a seed priming and type of species. however, few research studies have so far investigated the impact of different seed priming on the total dry matter production as well as some physiological responses in alhagi species.materials and methodstwo separate experiments was conducted to investigate seed priming (non-priming, hydro priming, hormonal priming with 50 ppm gibberellin and hydro priming + hormonal priming with 50 ppm gibberellin) and different salinity levels (urban water source with ec=0.96 ds.m-1, 8 and 16 ds.m-1 using seawater persian gulf) on seed germination, dry matter and some physiological response of alhagi species (alhagi maurorum esfahan ecotype and a. graecorum khuzestan ecotype). the first experiment (seed germination) was carried on in the petri dish culture and second experiment (in the pot) at the field conditions was performed under split factorial experiments were conducted based on a randomized complete block design with four replications in department of plant production and genetics, faculty of agriculture, shahid chamran university (ahwaz, iran) during 2020-21. meanwhile, during research, after calculating of the leaching fraction, ec of the root environment was controlled three times with an interval of one month by preparing a saturated extract from the pot bed and only in the third sampling was performed a leaching in the treatments of 16 ds m-1, with a salinity level lower than the studied treatment (8 ds.m-1).results and discussionthe results showed a significant effect of salinity × priming × species interaction on all studied traits except for transpiration rate, na and k content. in the case of transpiration rate, only the effects of salinity and priming were significant. mean comparison results showed that the highest amount of seed germination, total dry matter, net photosynthesis rate, sub-stomata co2 concentration, photosynthetic water use efficiency and number of leaves per plant in a. graecorum khuzestan ecotype under non-salinity stress and hydro priming + hormonal priming with 50 ppm gibberellin treatment (increased by 29.1, 1.52, 26.8, 98.7, 15.6 and 38.8 percent respectively compared to the non-priming and non-salinity stress treatment in the a. maurorum esfahan ecotype). the highest level of mesophilic conductance was observed in a. graecorum khuzestan ecotype under non-priming and 8 ds.m-1 salinity stress treatment (with an average of 0.492 mmol co2.m-2.s-1).conclusionin this experiment, results showed significant differences in total dry weight, net photosynthesis rate, transpiration rate, sub-stomata co2 concentration, mesophyll conductance and photosynthetic water use efficiency between two alhagi species at different salinity conditions using persian gulf water. indeed, dry matter and photosynthesis traits in both alhagi species responded negatively to increasing salinity levels and increasing of salinity up to, 8 ds m-1 induce the loss in physiological responses. among the priming treatments, the hydro priming + hormonal priming with 50 ppm gibberellin showed a more favorable condition in the two alhagi species in terms of the studied traits. finally, in cultivation and development of alhagi species for breeding programs in saline coastal lands and for the restoration of pastures, according to the results, a. graecorum khuzestan ecotype under the combined treatment as hydro priming + hormonal priming with 50 ppm gibberellin, recommended for high production.