In vitro salinity stress mediates grass pea genotypes' (Lathyrus sativus L.) responses

This study was carried out to determine the tolerance of grass pea genotypes to salinity stress at callus and seedling stages under in vitro conditions. The calli and seedlings of six selected tolerant genotypes based on the primary screening in the field were separately exposed to salinity treatments (0, 125 mM) in vitro. Salinity was imposed with NaCl during in vitro culture, and it significantly affected all seedling traits. Genotype of Iran had the lowest seedling dry weight and therefore was more sensitive to salinity stress. According to salinity tolerance indices for seedlings, genotype Greece-III was characterized as high-yield and relatively high-salt-tolerant genotype. Salinity significantly affected callus size, callus RWC, callus RGR, and callogenesis index. Calli fresh and dry weights were not affected by the treatments. For callus dry weight, genotype Greece-III had the highest mean; and the lowest mean belonged to Greece-I. The stress tolerance indices showed that the highest values belonged to genotype Greece-III, which showed high yield and yield stability and so reasonable salinity tolerance. Cluster analysis divided the genotypes into two separate groups. The first cluster consisted of Iran, Greece-II, and Greece-III genotypes, and the second cluster consisted of Bangladesh, Canada, and Greece-I genotypes. Cluster analysis potentially separated the tolerant and sensitive genotypes to salinity in terms of callus dry weight. Grass pea callus and seedlings were able to survive at 125 mM salinity. Salinity did not affect callus dry and fresh weights, but its effect was remarkable on seedling dry and fresh weights (55% less than control). Therefore, calli were reasonably salinity tolerant. The present study suggests that grass pea was reasonably tolerant to salinity and can survive under salinity conditions during the seedling and callus stages.University of MaraghehThis study was funded by and carried out in the University of Maragheh. These results were from MSc thesis of Mrs. Zahra Khosravi

Allelopathy of heliotropium europaeum (Boraginaceae): Influence on small grain cereals

In this research, probable allelopathic effects of Heliotrope were investigated on early growth of wheat and barley. Aqueous extracts of the plant at 5, 10, 15 and 20% concentrations were prepared from whole dried plants and distilled water was used as control. Results indicated that released allelochemicals from Heliotrope had inhibitory effects on germination and seedling growth of the test seeds when compared with the control. With increasing aqueous concentrations the inhibitory effects were severed and the highest concentration (20%) had maximum inhibitions on both traits. The results also revealed that the sensitivity of the plants to allelochemicals was different. Wheat was more tolerant than barley to the materials. The results also showed that the root growth was more susceptible than shoot growth under chemical stresses. Allelochemicals changed seed reserve remobilization rates. The weight of reserve mobilization and seed reserve depletion percentage decreased while seed reserve utilization efficiency improved. These findings suggest that the catabolism reactions are more susceptible to allelochemicals than anabolic reactions. It was concluded that Heliotrope had a powerful allelopathic effect on the early growth of the crop plants and the interference of Heliotrope was a species-specific phenomenon

Does physicochemical pre-treatments can alleviate germination and dormancy of Sophora alopecuroides seeds?

A factorial experiment in completely randomized design was conducted with three replications in 2012 at the University of Maragheh, Iran, to evaluate the different pre-treatments effects on germination of Sophora seeds. To release the physical dormancy, seeds were exposed to: mechanical scarification; sulfuric acid (65%) for 15 min; sulfuric acid (65%) for 30 min. To examine the existence of physiological dormancy, Seeds were tested with following solutions in the seed bed; distilled water; saturated soil extract solution ; KNO3 (34 mg\L); Gibberllic acid (20 ppm) and KNO3 (34 mg\L)+ GA3 (20 ppm). The results showed that Germination percentage (GP), Seedling fresh weight (SFW), Seedling dry weight (SDW), Grain fresh weight (GFW), Grain dry weight (GDW) and Resource remobilization (PM) were significantly affected by scarification treatments whereas the influence of media solutions on mentioned traits were not statistically significant. Among the scarification treatments, sulfuric acid (65%) for 30 min improved seed germination percentage from 2.22% to 81.66%. However, the rest treatments had a negligible effect on the germination percentage in comparison with control. Sulfuric acid scarification enhanced seedling properties and the highest values were obtained from sulfuric acid (65%) for 30 min. In conclusion, it seems that the primary control of germination in sophora seeds is located in the seed coats and scarification with sulfuric acid (65%) for 30 min can easily eliminate these limitations and seed dormancy

Evaluation of Adaptability of Different Cultivated Ecotypes of Saffron Under Maragheh Climatic Conditions

In order to evaluate the adaptability of saffron ecotypes under Maragheh climatic conditions, an experiment was conducted based on a Randomized Complete Block design (RCBD) with three replications during the growing seasons of 2013 and 2014. The ecotypes used were Bardaskan, Abrud, Sabzevar, Bonab1, Torbat-e-Heydarieh, Bonab2, Marand1, Marand2, Kashmar, Taybad, Esfiukh and Mahvelat. The following traits were evaluated: fresh weight of stigma, dry weight of stigma, length of stigma, emergence percentage, emergence rate, flowering percentage, flowering rate, dry and fresh weight of flowers and dry yield of stigma in the area. The results showed that the ecotypes established very well in the first year of the experiment, but frosty days of the winter severely damaged Abrud, Taybad and Esfiukh ecotypes. There were significant differences among the ecotypes for the traits: the number of flowers, emergence, flowering percent and fresh weight of saffron. Also, a significant difference was recorded among the studied ecotypes for flowering and emergence rate. The highest emergence percentage was observed in Marand 2, while Sabzevar had the highest rate of flowering and flowering percentage. Despite the low yields for Marand1 and Sabzevar in the first year of the experiment, these ecotypes with 1.5 and 1.4 kg per hectare produced the high stigma yields, respectively in the second year. In conclusion, the results showed that the ecotypes of Marand are suitable for cultivate in the Maragheh climate conditions and the use of exotic corms is not recommended. Adaptability, Corm, Flowering percentage, Stigma yiel

The Effect of Sowing Date and Plant Density on Morphology, Phenology and Yield Variables of Maize Hybrids in Bonab Region

In order to investigate the effect of sowing date and plant density on morphology, phenology and yield variables of 704, 540 and 500 maize hybrids, a factorial experiment was carried out based on complete randomized block design with four replications. In this research, row space was fixed at 75cm and inter row spacing was 12, 15 and 18cm that create 111500, 89000 and 74000 plants per hectare, respectively. In this study, the highest number of kernel rows per ear, with 18.1 rows, was obtained by hybrid 500. Whereas, the highest number of kernels per row, with 24.4 kernels, was produced by hybrid 704. But, among studied hybrids, the number of kernel per ear was not significant. The results also showed that the highest forage yield, with 48.1 ton per hectare, was obtained by hybrid 704 and hybrids 540 and 500 with 42.6 and 40.8 ton forage yield per hectare ranked next, respectively.  High performance of hybrid 704 depends on its high biomass production so that the dry weight of hybrid 704 was 118.9 gram per plant that had significantly differences compared to other hybrids. With increasing of plant density, forage yield per plant was decreased significantly and forage yield per unit area was increased.  The highest forage yield per unit area, with 46.3 ton per hectare, was acquired from 12cm row spacing. The study of phonological traits demonstrated that in Bonab region only hybrid 500 could reach to maturity stage (dough stage) for harvest.  With respect to high quality of maize forage for silage at dough stage, the hybrid 500 for is suitable and if the purpose is grazing, sown of hybrid 704 with highest density is recommended

Allelopathic potential of Chrozophora tinctoria on early growth of Barley and Wheat

A laboratory bioassay was conducted to investigate the allelopathic effects of Chrozophora tinctoria on germination and seedling growth of barley and wheat. Aqueous leave extracts of C. tinctoria at 5, 10, 15 and 20 % concentrations were prepared and distilled water was used as a control. Results showed that germination percentage of two species decreased with increasing the extract concentrations; however, wheat germination was relatively resistant to allelochemicals than barley. In contrast to germination behavior, seedling traits showed different responses. The extracts improved seedling dry weights, particularly barley, whereas seedling lengths were inhibited. Roots of both species were more affected than shoots by extracts. The extracts reduced seed reserve mobilization significantly (p≤0.05). It was concluded that the used extract had inhibitory effects on seed germination of the crops; however, at seedling stages the effects were severely reduced

Dryland soil water storage susceptibility to different soil tillage practices under Vetch- Wheat crop rotation

Crop rotation and soil tillage are two practices which would result in better use of water resources. So in order to investigate the effects of different crop rotation and soil tillage practices on soil water storage, a multi-annual experiment employing two crop rotations and six tillage practices was carried out in dry-land condition of Maragheh, northwest of Iran during year 2007 till 2011. Results showed that autumn cultivation of the common vetch (CR1) compared to spring cultivation of the common vetch (CR2) left more water in the soil for the following wheat cropping in the next years and subsequently increased biological and grain yield of wheat. It was also notified that the increase of water storage in second sampling depth (15-30 cm) was significantly more than two other depths (0-15 and 30-45 cm). Results also depicted that the tillage practice applying "chisel plough + cyclo-tiller + seed drill (TP1)" compared to other practices and especially the routine tillage of the region moldboard plow + disk harrow + manual seed broadcasting, TP5) significantly increased soil water storage. The mentioned tillage practice (TP1) markedly decreased the bulk density of soil and increased biological and grain yield of wheat, as well. Therefore, applying TP1 tillage practice beside autumn cultivation of common vetch in rotation with wheat would be a good strategy to increase soil water storage and crop yield in dry-land conditions