هنرمند

Occurrence of drought stress at grain filling period is the prominent and inevitable characteristic of arid and semi-arid regions. The objectives of this research were to determine the effect of water deficiency and the role of current photosynthesis on grain filling, photosynthesis and gas exchange. Therefore, an experiment was carried out in a split-plot design based on a randomized complete block design with three replications at the Research Farm of Razi University in Iran during 2010-2011 cropping season. The irrigation treatments including non water stress (full irrigation over the whole season) and water deficiency stress (irrigation cessation after anthesis stage) were considered as main plots, while the factorial combination of eight wheat cultivars including Bahar, Parsi, Pishtaz, Pishgam, Chamran, Zarin, Sivand, Marvdasht and DN-11 line and the source manipulation treatments including control (Non source limitation), defoliation of flag leaf, defoliation of all leaves except the flag leaf, removing awns and shading over ears, were considered as sub-plots. The results showed that, post-anthesis water deficiency significantly decreased grain yield (22.2%) and 1000-seed weight (18.6%) compared to the control treatment and Removal of photosynthetic sources of assimilates reduced grain yield owing to grain weight reduction. The contribution of spike photosynthesis to grain filling (35.4%) was greater than the flag leaf (18.6%) and lower leaves (18.5%) and also, awns had the lowest contribution to grain filling (3.3%). Grain filling period was shortened during water deficiency stress, so that it reduced from 35 days under control conditions to 28 days under stress conditions, whereas it caused an increase in seed filling rate. Moreover, results indicated that photosynthetic source limitations caused an increase in photosynthetic rate and gas exchange. This increase reflects the compensatory role of photosynthetic rate of remained leaves in preventing yield loss.

Plant growth regulators are the main factors in grain yield formation However, their physiological roles have not been fully identified. On the other hand, water stress is the main factor in reducing grain yield and germination characteristics. To this end, two experiments were carried out in the research farm and laboratory of Campus of Agriculture and Natural Resources of Razi University in Iran during 2010-2011 and 2011-2012 years in a split-plot factorial arranged in a randomized complete blocks design with three replications. The irrigation treatments including non water stress and water deficiency stress (from anthesis and continued until physiological maturity). The wheat cultivars including Pishtaz, Marvdasht, DN-11and 336 and the foliar application of indole acetic acid (dose of 50 μM)treatments including control, used at the beginning of grain growth (from anthesis) and at the beginning of grain filling (from 14 days after anthesis) at the entire plants. Under non water stress, the grain yield of Marvdasht was greater than other cultivars. More yield reduction of this Marvdasht in water deficiency compared to other cultivars showed more sensitivity of this cultivar to post-anthesis water deficiency and DN-11 in this situation had the lowest grain yield reduction. Foliar application of indole acetic acid (IAA) at the beginning of grain growth caused the most increase in grain yield. In this situation, IAA caused more increase in the grain yield of Marvdasht cultivar. But, this treatment at the beginning of grain filling did not have such effect. Seeds were obtained from the field were studied in the view of germination and seedling growth characteristics in the laboratory and the result showed that, plumule length and germination percentage were not affected by post-anthesis water deficiency. Under post-anthesis water deficiency, Plumule to radicle ratio and germination rate significantly increased and other parameters showed a significant decrease. Mean comparison of foliar application of IAA at the beginning of grain filling showed that this significantly increased germination characteristics. With respect to these results, Auxin may via positive effects on seed quality and not quantity (seed weight) may be had positive effects on seed germination characteristics.

This article, based on a comparative study, deals with the question of mental health of the parents of mentally retarded children. In this study the mental health of the parents of the educable mentally retarded children were compared to that of the non- retarded children. The subjects sampled randomly consisted of 280 parents (mother and fathers equally), of whom 140 had educable mentally retarded children and 140 had non- retarded children in the primary schools of Abadan. The information needed, was obtained using a 90- question- scale questionnaire (SCL 90- R), the validity and reliability of which were compatible with that of the original scale. The research design a causal- comparative one. The results show a significant difference between the mental healths of the two groups of parents. Moreover; according to this research, the negative effects of having a mentally retarded child is more obvious in mothers than fathers.