تأثير المحتوى الرطوبي ونوع التربة في بعض المؤشرات الفسلجية والكيموحيوية لنبات الحنطة Tritticum aestivum L. وعلاقة ذلك بالبوتاسيوم المضاف.

The effect of moistur contect and soil type in some physiological and biochemical characters of Wheat

        Anexperiment conducted by using plastic pots in the Department of Biology- College of Education for Pure Science / University of Karbala for the growing season 2013 – 2014. Afactorial experiment within a (CRD) was adopted to study the effect of  moisture contect and soil types in some physiological and biochemical characters of Wheat                          (Tritticum aestivum.) class tahadi and its relationship with addition of potassium. Three treatments depending on the field capacity at the amount (50 , 75 , 100 %) three levels of potassium nitrate (0 , 2000 , 4000) mg K . L^-1 and , two types of soil (loam sand and clay) were used (3×3×2) treatment for moisture stress , potassium nitrate and soil type respectively , with three replicates.

 Results could be summarized on following:

1- loamy sand soil give Significant increase of plant height , number of tillers . pot^-1, area of ​​flag leaf (cm²) , chlorophyll content in leaves , proline contant , activity of  POD , CAT and SOD enzymes . As well as yield parameters , number of spikes per plant , number of  grains per    spike ^-1 , weight of 1000 grains (gm) , biological yield (gm) , grains yield (gm) .  The clay is produced the highest number of  relative water content % and N, P and K content in the plant and the protein in grains (%) .

 2– A response to added potassium fertilizer has been obtained . the best level was 4000 mg L ^-1, giving best results in plant height , number of tillers , area of ​​flag leaf (cm²) that and for physiological indicators which were  chlorophyll content , the activity of  POD , CAT and SOD enzymes in leaves and relative water content and yield parameters  number of  grains . spike ^-1 , weight of 1000 grains (g) , biological yield (gm) , grains yield ( gm) , harvest index % the nitrogen% phosphorus %, potassium% and protein% all of them in grains , Values of proline . The activity of POD , CAT , SOD enzymes in leaves decreased at the level of 4000 mg L ^-1., compared to the control K0 .

3–Water stress at 50 % from field capasity , has given the lowest values to all studied vegetative growth characteristics included plant height , number of tillers.pot^-1  and the area of flag leaf (cm²) , Physiological indicators chlorophyll content in leaves , relative water content (%) , yield parameters (  number of spikes .plant^-1 ,  number of  grains . spike^-1 , weight of 1000 grains (g) , biological yield (gm) , Grains  yield (gm) , and  the percentage of phosphorus in grain % ) ,  respectively except the proline value , the activity of peroxidase POD , catalase CAT and superoxide dismutase SOD enzymes in leaves and the ratio of nitrogen % , potassium % , protein % in grains were increased in the level of 50% of field capacity . While the level of water stress gave the highest values by adding irrigation water of 100% of field capacity, except proline concentration and the activity of peroxidase POD , catalase CAT and superoxide dismutase SOD enzymes in leaves and the percentage of protein , nitrogen and potassium in grains.

4– The interaction between the ecological factors showed a  significant effect among  all studyes in part character in the wheat plant.