تأثير الرش بحامض الجاسمونك في تقليل الاجهاد الملحي لمحصول الذرة الصفراء (.Zea mays L)

The effect of spraying jasmonic acid on the Relieve the salt stress of maize ( Zea mays L.)

The experiment was conducted during Fall of 2017 in the University Field of AL-Qasim Green   / College of Agriculture southern of Babylon province  to study the effect of the spraying Jasmonic acid on reducing the effect salt stress of Maize crop ( Zea  mys L.), Factorial experiment was applied using a split plot design   (SPD) with three replicates . Treatments included four levels of  water irrigation salinity represent hereafter by (S) which is (1.2, 2, 4 and 6 ds m^-1) and four Jasmonic acid concentrations represent hereafter by (J) (i.e. zero , 5 , 10 and 15 mg L^-1) with foliar applications  .

Means treatments three replications and the means undergo to ( LSD ) test at 0.05 probability  level , in order to know the effect range of the two study treatments to numbers of morphological , physiological and  yield   and component yield of maize plants American Hybrid 34N84  and the results came as follows :

Results showed that levels of irrigation with saline water significantly affected the traits . The level 6 ds m^-1 lower  the values of  vegetative growth represented by the leaf area , the plant height , Number of leaves , shoot dry weight , Leaf Area Index , stem diameter ,the root dry weight , the root size  , the root length and the root diameter  and which amounted to 288.7 cm²  , 114.58 cm , 9.86 , 93.5 g , 1.91 , 18.64 mm , 13.29 g , 13.74 cm² , 35.53cm , 2.20 cm respectively . As well as on some yield component and Physical characteristics , represented by the content of the in chlorophyll leaves , ear length , grain number , grain yield , weight of 300 grain, concentration of nitrogen , Potassium , Calcium and Magnesium in the leaves and which amounted to 35.73 unit Spade , 13.32 cm , 179.8 , 1.98 tons. ha^-1 , 69.91 g , 3.09 mg.g^-1 dry weight , 2.81 mg.g^-1 dry weight , 7.05 mg .g^-1 dry weight and 18.70 mg .g^-1 dry weight sequentially . On the other hand given the level of saline water 6 ds m^-1  gave highest of some of traits ratio of root weight to  shoot , permeability of cellular membrane ,  the concentration of proline , the activity of antioxidant enzymes Superoxide dismutase (SOD) and Catalase (CAT) and concentration of sodium in the leaves , which amounted to 0.144 , 39.37% , 12.62  micromol.gm^-1 , 9.30 unit .g^-1 , 73.13 unit .g^-1 and 4.36 mg.g^-1 dry weight sequentially .

Levels of Jasmonic acid added significant effect in the traits , And given the level Jasmonic acid 5 mg L^-1 higher rate in most of the qualities represented by the leaf area ,  plant height , Number of leaves , shoot dry weight , Leaf Area Index , stem diameter , root dry weight , the root size  , root length , root diameter , content of chlorophyll leaves , ear length , grain yield , concentration of nitrogen , Potassium , Calcium and Magnesium in the leaves which amounted to 387.0 cm² , 158.77cm , 13.03 , 162.1 g , 3.41 , 22.78 mm , 17.83 g , 19.21 cm³  , 39.37 cm , 2.47 cm , 53.89 unit Spade , 19.32 cm , 6.54 tons. ha^-1 , 11.46 mg.g^-1 dry weight , 25.82 mg.g^-1 dry weight , 4.73 mg.g^-1 dry weight , 3.92  mg.g^-1 dry weight sequentially . Whereas the same  level of  Jasmonic acid gave lower rate of the Ratio of root weight to shoot , permeability of cellular membrane and the sodium concentration in the leaves amounted of 0.112 , 21.72% and 3.40 mg.g^-1 dry weight sequentially .

Jasmonic acid of 15 mg .L^-1  showed the  highest mean in the character of the activity of antioxidant enzymes Superoxide dismutase (SOD) and Catalase (CAT) amounted of  7.23 unit .g^-1 and 51.88 unit .g^-1 . On other hand , the level  15 mg .L^-1  Jasmonic acid reduced the mean value of proline concentration of  9.49 µmol.g^-1 .

The interactions between water irrigation  salinity levels and Jasmonic acid had  a marked influence on all studied  characteristics  the least interaction found to be 5 mg .L^-1 Jasmonic acid  with all level and salinity.