Pigments apparatus and anthocyanins reactions of borage to irrigation, methylalchol and titanium dioxide

Abstract

This study was done to evaluate the effect of methanol and nano TiO2 foliar application on photosynthetic apparatus, anthocyanin and changes of nitrate reductase in borage (Borago officinalis L.) under deficit irrigation. Tests were done as a split factorial experiment set up as a completely randomized block design with four replications, in the year 2012, at Shahriyar City, Iran. Irrigation conditions were the factors tested in the main plots: deficit irrigation condition (irrigation every 7 days) and irrigation every 14 days. Methanol solutions 0 (control or sprayed with water), 15%, 35% and 45% (v/v) and, nanoTiO2 treatment (0 or control and nano TiO2 at concentrations of 0.01%, 0.03% and 0.05%) were tested in the sub plots. Plant characteristics under evaluation were those of; chlorophyll (Chl) a,b and total chlorophyll, Spad value, net photosynthetic rate, rubisco carboxylase activity, anthocyanin and nitrate reductase enzyme (NR). Also evaluated were the effects of interaction of deficit irrigation and methanol on all measured traits, and results determined the effect as significant with the exception of NR and interactions of deficit irrigation and nano TiO2 on all measured traits. Test results showed that maximum amount of traits at deficit irrigation was achieved by spraying with 45% v/v oncentration of methanol and nano Tio2 at the concentration of 0.05%. But the best treatments under normal irrigation were 15% v/v of methanol and 0.03% of nano Tio2. but at the methanol concentration of 45% and non-application of nano Tio2 under normal irrigation had the least effect. In summary, results of these tests determined that application of methanol and nano Tio2, can promote plant resistance to drought stress (particularly borage plants).