Water-deficit stress is the most important environmental factors limiting plant growth, and production. Nano-titanium dioxide (nano anataseTiO 2 ) can have various profound effects on the crop physiological, biochemical and morphological characteristics. In the present research, the influences of different concentrations ofTiO 2 nanoparticles (NPs) (0, 10 and 40 ppm) and water-deficit stress on Dragonhead (Dracocephalum moldavica L.) were investigated in a factorial experiment based on randomized complete block design with three replications. Results showed that under normal irrigation, foliar application of 10 ppm TiO 2 NPs increased plant shoot dry mass and essential oils content. Under water-deficit stress condition, plants treated with 10 ppm TiO 2 NPs had more proline and much less H 2 O 2 and malondialdehyde content as compared to untreated plants. Therefore, it can be concluded that proper concentration of TiO 2 NPs probably can be used as an exogenous stimuli for improvement of shoot growth and essential oil content in plants. Furthermore, water-deficit stress-induced damages such as oxidative stress and membrane damage can be ameliorated by foliar application of TiO 2 NPs at appropriate concentrations. Sušni stres je eden izmed najpomembnejših okoljskih dejavnikov, ki omejujejo rast in produktivnost rastlin. Uporaba nano delcev titanovega dioksida (TiO 2 nano anataza) ima lahko velike učinke na fiziološke, biokemične in morfološke lastnosti gojenih rastlin. V tej raziskavi je bil v naključnem faktorskem bločnem poskusu preučevan vpliv različnih koncentracij nano delcev TiO 2 (0, 10 in 40 ppm) in sušnega stresa na moldavsko kačjeglavko (Dracocephalum moldavica L.) v treh ponovitvah. Rezultati so pokazali, da sta se suha masa in vsebnost eteričnih olj povečali pri normalnem namakanju in listnem dodajanju 10 ppm TiO 2 nano delcev. V razmerah sušnega stresa so vsebovale rastline, ki so bile tretirane z 10 ppm TiO 2 več prolina in mnogo manj H 2 O 2 in malonildialdehida v primerjavi z netretiranimi rastlinami. Na osnovi tega bi lahko zaključili, da bi z uporabo primerne koncentracije nano delcev TiO 2 kot zunanjega stimulanta, lahko izboljšali rast poganjkov in vsebnost eteričnih olj pri tej rastlini. Poškodbe kot sta oksidativni stres in poškodovanost membran, ki nastanejo zaradi sušnega stresa, bi lahko ublažili s foliarno aplikacijo primerne koncentracije nanodelcev TiO 2 .

No abstract

Safflower is one of important crop in semi-arid regions of the world, where the precipitations are limited. In order to investigate the effect of foliar spray of nano-silicon dioxide (10 and 20 mM) and nano titanium dioxide (25 and 50 mM) and water-deficit stress (irrigation after 110 mm evaporation) on growth parameters and yield components of spring safflower a field experiment was carried out at the highland semi-arid region, in, North West of Iran. Water deficit stress significantly reduced morpho-physiological traits such as ground cover, canopy width, leaf fresh mass, leaf are and plant height) as well as yield components (e.g. capitulum diameter, seed mass and seed number per capitulum). However, the plants grown under water deficit condition showed the higher harvest index than well irrigated plants. Comparison of the foliar treatments showed that the both nano-particles (silicon and titanium) improved the plant growth and yield components over the control. However, the effect of nanosilicon was more prominent than titanium. The highest amount of seed oil was recorded under well irrigated condition (irrigation after 60 mm evaporation) with foliar application of nano-titanium. The percentage of palmitic acid, arachidic acid and myristic acid in seed increased by nano-titanium application. Altogether, principal component analysis indicated that spray of 10 mM nano silicon dioxide was best foliar treatments under all moisture regimes.Key words: safflower; agronomic traits; foliar spraying; nanoparticles; principal component analysis; semi-arid region IZVLEČEK UČINKI SILICIJA IN TITANA NA RAST ŽAFRANIKE (Carthamus tinctorius L.) V RAZMERAH POMANKANJA VODEŽafranika je pomembna poljščina v semiaridnih območjih, kjer so padavine omejene. Z namenom ugotavljanja učinkov pršenja listov z nano-silicijevim (10 in 20 mM) in nano titanovim dioksidom (25 in 50 mM) ter stresa zaradi vodnega deficita (namakanje po 110 mm evaporacije) na rastne parametre in komponente pridelka pomladanske žafranike je bil izveden poljski poskus na višinskem semiaridnem območju severno zahodnega Irana. Vodni deficit je značilno zmanjšal morfološko-fiziološke lastnosti (pokritost tal, širino krošnje, svežo maso listov, listno površino in višino rastlin) kot tudi komponente pridelka (premer koška, maso semen in število semen na košek). Kljub temu so imele rastline, ki so rastle v razmerah pomanjkanja vode večji žetveni indeks kot dobro namakane. Primerjava foliarnih obravnavanj je pokazala, da so oboji nano delci (silicijevi in titanovi) izboljšali rast rastlin in komponente pridelka v primerjavi s kontrolo. Učinek silicijevih nano delcev je bil bolj izražen kot titanovih. Največja vsebnost olja v semenih je bila v dobro namakanih rastlinah (namakanje po 60 mm evaporacije) s foliarno dodajanimi nano delci titana. Odstotki palmitinske, arahidonske in miristične kisline v semenih so se povečali po uporabi nano titanovih delcev. Analiza glavnih komponent je pokazala, da je bilo pršenje z 10 mM nano silicijeva dioksida najboljše foliarno...

Environmental stresses and rhizosphere microorganisms affect growth parameters and accumulation of active ingredients especially in plants with medicinal properties. The present study examined the effects of chamomile (Matricaria chamomilla L.) seedling inoculation with Pseudomonas fluorescens PF-135 strain on its growth parameters, photosynthetic pigments, proline, malondialdehyde (MDA), and hydrogen peroxide (H 2 O 2 ) content, and essential oil concentration at both regular watering and water deficit experiments. Based on the obtained results, water deficit stress reduced root dry mass, and flower fresh and dry mass as well. However, amount of H 2 O 2 and MDA in root and shoot tissues were considerably lower in inoculated plants compared to non-inoculated ones under both normal watering and water deficit regimes. It indicates that lipid peroxidation and production of reactive oxygen species has been diminished in inoculated plants. Also, essential oil content in inoculated plants significantly increased compared with that of noninoculated ones under water deficit stress condition. It can be concluded that P. fluorescens PF-135 strain has an outstanding potential to alleviate adverse effects of water deficit on plant growth, and hence can be used as an excellent PGPR in order to boost chamomile productivity especially under water deficit stress condition.Key words: PGPR; chamomile; essential oil; injury indices; water deficit stress IZVLEČEK FIZIOLOŠKE IN BIOKEMIČNE SPREMEMBE PRAVE KAMILICE (Matricaria chamomilla L.) VZPODBUJENE Z BAKTERIJO Pseudomonas fluorescens IN POMANKANJEM VODEOkoljski stresi in mikroorganizmi v rizosferi vplivajo na rastne parametre in na kopičenje aktivnih snovi, še posebej v rastlinah z zdravilnimi lastnostmi. V raziskavi so bili preučevani učinki inokulacije sejank kamilice (Matricaria chamomilla L.) s sevom bakterije Pseudomonas fluorescens PF-135 na njene rastne parametre, vsebnost fotosinteznih barvil, prolina, malondialdehida (MDA), vodikovegan peroksida (H2O2) in eteričnih olj v razmerah rednega zalivanja in ob pomanjkanju vode. Rezultati so pokazali, da je pomanjkanje vode zmanjšalo suho maso korenin in svežo ter suho maso cvetov. Količini H2O2 in MDA v tkivih korenin in poganjkov sta bili manjši pri inokuliranih rastlina v primerjavi z neinokuliranimi pri obeh vodnih režimih. To kaže, da je bila peroksidacija lipidov in tvorba reaktivnih zvrsti kisika manjša pri inokuliranih rastlinah. Tudi vsebnost eteričnioh olj se je pri inokuliranih rastlinah značilno povečala v primerjavi z neinokuliranimi v razmerah pomanjkanja vode. Zaključili bi lahko, da ima sev bakterije P. fluorescens PF-135 izjemen potencial za odpravljanje škodljivih učinkov pomanjkanja vode na rast rastlin in bi bil lahko uporabljen kot odlična PGPR snov za povečanje pridelka kamilice, še posebej v razmerah pomanjkanja vode.

No abstract