تأثير اضافة الأوكسين (IAA)والزنك المخلبي النانوي في تحمل نبات الحنطة .Triticum aestivum L للأجهاد الملحي

The effect of Auxin and chelated nano Zinc adding on tolerance of Salainty stressed Wheat(Triticum aestivum L.)

Abstract
The pot experiment was carried out at the Faculty of Agriculture, University of Kerbala during 2019-2020 agricultural season to study the response of wheat plant (Triticum aestivum L.) grown in sandy loam soil under different salinity levels of irrigation water to different concentrations of the auxin hormone and nano-chlated zinc added by foliar application . The experiment was designed as a factorial experiment within a completely randomized design (CRD)with three replications.,Treatments included three factors, the first factor ( A ) represented by foliar application of wheat plants with auxin at a concentration of (0, 20 mg L-1), and the second factor ( Z ) involved the foliar application with three concentrations of Nano-chelated zinc (0, 1, 2 g L-1) applied before elongation and at booting stages . The third factor ( S ) was irrigation with different water quality (2, 4, 8 dS m-1 ) .This experiment included 54 experimental units. Some phenotypic growth traits, some yield characteristics and some physiological indicators were studied . Some nutrients were determinel in each of the plant roots, leaves and grains, the effectiveness of some plant enzymes and plant hormones were estimated and the results were statistically analyzed. The averages btween mean were compared using the least significant difference at a 0.05 level of probability .
The study showed the following results:
1-The effect of the auxin hormone was significant in the characteristic of leaf area, root size, root diameter, absolute growth rate, relative growth rate, chlorophyll proline, spike length, average number of grains, biological yield, grain yield, nitrogen and protein.
2-The effect of nano-chlated zinc significantly on plant height, leaf area, number of tillers,, root size, absolute growth rate, relative growth rate, chlorophyll, relative water content, proline, SOD, CAT, POD, average number of grains, biological yield and grain yield .
3-Salinity had a significant effect on all studied traits of the wheat plant .
4-The bi- interactions between auxin and irrigation with different salinity water significantly affected some phenotypic and physiological characteristics, nutritional status and some enzyme activity. The spraying treatment was with auxin A1 and salinity of irrigation water at 1 dS m-1 was the best in increasing the number of tillers, chlorophyll, number of spikes, root size, root length, zinc concentration in leaves, and potassium concentration in grains, as it amounted to 4.31 tillers, 49.30 spads, 2.12 spikes, 3.55, 14.55 cm, 47.74% and 1.365%, respectively.
5-The bilateral interactions between spraying with nano-chlated zinc and foliar application with auxin showed a significant effect on some of the studied characteristics, so the best treatment was spraying with nano-chlated zinc at 2 g L-1. Foliar spray with auxin hormone 20 mg L-1 increased plant height, root diameter, absolute growth, relative growth, proline, SOD, CAT, POD, grain yield, biological yield, number of grains, grain nitrogen concentration and protein content.
6-The bilateral interactions between foliar spraying with nano-chlated zinc and irrigation with different salinity of water showed a significant effect on most studied characteristics. The treatment of irrigation with saline water at 2 dS m-1 and the foliar spray with nano-chlated zinc 2 g L-1 was the best in most of the studied characteristics. While the interactions were insignificant on the of root diameter.
7- The tri- interactions between spraying with nano-chlated zinc and foliar spraying with auxin and irrigation with different salinity water showed a significant effect on most of the studied characteristics. The treatment of spraying with nano chelated zinc at 2 g L-1and irrigation with saline water at 2 dS m -1 and foliar spray with auxin at 20 mg L-1 gave best values at plant height, number of tillers, root length, absolute growth rate, chlorophyll, number of spikes, length of spike, weight of 1000 grains, and potassium concentration giving 82.33 cm, 4.80 tillers Plant -1 ,14.92 cm ,1.42 , 50.66 units of spad , 2.20 spikes Plant -1 , 14.26 cm , 36.96 gm and 1.443%, respectively. The treatment of spraying with nano-chlated zinc 1 g L-1 and irrigation with saline water 2 dS m -1 and a foliar spray plants with auxin 20 mg L-1 gave Zn concentration incrmant in the leaves by 58.18%. The treatment of non-spraying with nano-chlated zinc and irrigation with saline water at 8 dS m -1 and foliar spray with auxin at 20 mg L -1 was the best in increasing SOD, nitrogen concentration and protein content by 51.30 units. mg Protein-1 1.230% and 7.683%, respectively.