No abstract

The effect of an application of GA3 to in vitro rooting culture medium (MS + 30 g/l sucrose + 6 g/l agar +0.1 mg/l kinetin + 3.0 mg/l IBA + 0.5 g/l AC) of date palm for 6 months (1month interval) to adverse the salinity effects was studied. The plantlets were cultured on a medium with different concentrations of GA3 (0,20,25 and 30 mg/l) combined with various levels of salinity (0,10000,14000 and 16000 ppm NaCl + CaCl 2 2:1 by weight ) .The plantlets were incubated under controlled laboratory conditions (27 ± 2 C 0 and 6000 lux).These plantlets were transferred to the liquid culture medium as a pre acclimatization treatment (1/4 MS +3.0 mg/l IBA) for two weeks before transferring to the greenhouse. The results showed that salinity has a depressing effect on various growth parameters (shoot and root length, number of leaves and number of roots), in contrast salt stress increased proline which is considered a (compatible osmoticums), Na, Ca, Cl and total sugars contents. GA 3 application had a stimulated effect on the adverse effect of salinity stress on the growth parameters and survival percentage at the acclimatization stage. The advantage of GA 3 application under salinity levels is discussed.

Date palm (Phoenix dactylifera L.) a perennial monocotyledonous tree it’s have an ecological importance and economical role in several countries of Middle East and North Africa, date palm can’t be propagate by seeds, meanwhile the offshoots produced low numbers of offshoots for the given period, so tissue culture technique become a great important for produced the huge demand plantlets, the in vitro technique facing a problem as the contamination by bacterial and fungus that lead to loss the cultures, for eliminate this problem many treatments were used as chitosan 5 and 15 ml/l, AgNO3 4.0 and 7.0 ml/l, Zn 4.0 and 7.0 mg/l and cu 0.5 and 1.0 mg/l. as the main forms or as a nanoparticles NPs in addition to streptomycin 40 and 50 mg/l and AgNO3 + Sodium thiosulfate 0.5 and 1.0 ml/l were added to rooting stage medium for 3 subcultures for each, then these plantlets were acclimatized under greenhouse condition. Collected data were subjected to analysis of variance (ANOVA) and the means were compared following t-test using LSD values at 5%. The percentage of cultures contamination was to be found zero % with the treatments chitosan, silver nitrate AgNO3, in addition to the combination of Chitosan + AgNO3, chitosan + Zn and finally chitosan + Cu at all tested levels produced, while the treatments Zn and Cu at two tested levels produced 11% contamination, the observation of the vegetative growth and leaves contents of indoles and amino acids mg/g f.w. were found highest values under chitosan and AgNO3 and the combination in between as the main forms or as NPs treatments, as well as, the acclimatization stage presented the great survival percentage % under Chitosan and AgNO3 and combination in between as the main form or as NPs. The present study have been suggest that NPs chitosan, AgNO3 and the combination in between might be a promising method for reduced or eliminate the in vitro microbes,  reduced the harmful effects on the valuable date palm plantlets and increasing growth parameters.