Iranian Journal of Seed Science and Research
Year:2014 | Volume:1 | Issue:1|Papers Count:6

To determine the best method and time of priming on seedling characteristics of Echinacea purpurea seed in vitro and pot conditions, two separated experiments were carried out at the Faculty of Agriculture, University of Urmia, Iran. Both of experiments were factorial experiments on a randomize design. Treatments contain methods of priming (Hardening, hydrothermal, hydro priming, KCl2, CaNo3, NaCl, KNo3 and control) and time of priming (3 and 6 h). Results of the variance analysis indicated that there were significant differences between priming methods both in vitro and pot conditions. But it is not reported any differences between priming times in vitro condition. However, with the increasing length of priming time in pot condition, positive effects of priming methods on germination components were more. Point of interest in this study was that all priming methods didn’t improve germination components. NaCl priming in vitro and hydro thermal priming in pot condition reduced rate and percentage of germination as compared to control. However, in total, the different methods of priming had positive effects on germination characteristics of Echinacea Purpurea seed. Hardening and KCl2 priming at 6 h had the positive highest effects on rate and percentage of germination and seed vigor. Therefore, these methods can be used to increase quality and vigor of Echinacea Purpurea seed and subsequently increase plant tolerance to unfavorable environmental conditions as well as uniformity and seedling emergence.

In this study the shoot parts extracts of Datura stramonium prepared and was analysed using GCMS method. Three alkaloids including tropinon, tropin and atropine were found and extracted. The potential allelopathic effects of these compounds were evaluated in a factorial experiment based on RCBD with 2 replications on the germination and seedling growth of six corn hybrids including Sc- 301, Sc- 404, Sc- 500, Sc- 647, Sc- 700 and Sc- 704 Results showed that the three way interaction effect of alkaloid × concentration × hybrid is significant on germination percentage and rate. Highest inhibitory potential was related to tropinone while lowes values was found in tropine. Increasing the concentration of alkaloid, inhibitory effect was also increased. Root and shoot dry weight of all corn hybrids were affected by the inhibitory effect of tropine and atropine. Both characteristics were increased in all corn hybrids when were exposed to atropine. Generally, it was concluded that three different alkoloides are existing in patura which have different allelopathic effects and may influence the next crop plant. The mechanisms which are responsible for the inhibitory effects of these allelochemicals may be usefull for finding the componds which can be used as herbicides.

In order to evaluation of some seed germination and vigour indices of soybean commercial cultivars to seedling field emergence a laboratory and field experiment was conducted in seed and plant certification and registration institute at Karaj. Experiment conducted as factorial based on complete randomize design with12 treatments, 3 primary germinability, standard(80 percent), over standard(upper most germinability of each cultivar sample) and under standard(lowest germinability of each cultivar sample) of 4 soybean commercial cultivars, Williams and Sari(JK) procuced in Mazandaran province and Telar and 033 produced in Golestan province by 4 replication. Seedling length, seedling dry mater, normal seedling percent, abnormal seedling percent, final germination percent, mean germination time, coefficient of velocity of germination, mean daily germination, mean daily germination rate, seed length and weight vigour indices measured by standard germination test and seedling growth analysis test conduction. Also seeds planted in field and primary and final seedling emergence percent, seedling emergence rate and seedling cumulative emergence rate and seedling vigour index and seedling dry weight in field determined. Results revealed that seedling length and dry weight, coefficient of velocity of germination and seed length and weight indices and primary and final seedling emergence percent and  seedling vigour index in field affected by cultivar × primary germinability interaction and other studied indices affected by any of factors. Also seedling length and dry weight, normal seedling percent, daily germination rate and seed length vigour index increasing in high germinability seeds observed and these seeds had high and primary and final seedling emergence percent and seedling emergence rate at field and strong vigour seedlings. Generally Williams and 033 cultivars with over standard primary germinability seeds for almost laboratory and field indices significantly higher than in comparison of other cultivars. In standard germination test normal seedling percent in comparison of final germination percent had high correlation with final seedling emergence in field. Thereafter, seem normal seedling percent determination could suitable criterion of potential vigour of seeds for seedlings establishment in field.

To investigate the effect of seed biological treatment and fertilizer integration on yield and nutrients uptake of turnip (Brassica rapa L.), an experiment was conducted at research institute of rice during 2011 and 2012. The experiment was arranged base on randomized complete block design with three replications. Treatments were involved 9 levels: use of fertilizer and uninoculation, seed inoculation with Azotobacter chroococcum strain 12 and without nitrogen, seed inoculation with A. chroococcum strain 12 and full nitrogen, seed inoculation with Pseudomonas fluorescens strain 12 and without P fertilizer, seed inoculation with P. fluorescens strain 12 and full P fertilizer, seed co-inoculation (with P. fluorescens strain 12 and A. chroococcum strain 41) and without fertilizer, seed coinoculation and %100 N.P. fertilizer, seed co-inoculation and %50 N. P. fertilizer and without inoculation and fertilizer (control). Investigated characteristics were including plant height, stem diameter, nutrients content (N, P) in plant tissue, dried weight of leaf and tuber and fresh and dried forage yield. The results showed significant effect of seed biological treatment on all of investigated characteristics. This present findings showed that, fertilizer integrated management has important role in enhancement of turnip yield, and it could be suggested that these bacteria have positive effect on forage yield of turnip, and therefore can be used as complementary fertilizer.

In order to evaluation of Effect of storage conditions, duration and packaging on viability and vigor of soybean, an experiment was conducted as a factorial experiment (2×3×5) in the field (completely randomized block design and laboratory (completely randomized design) with three replications in agricultural and natural resources research center of Mazandaran, Iran in 2010-11 and 2011-12. This experiment was included 30 treatments (first factor: five types of packaging as a) two layer paper pack, b) three layer paper pack, c) two layer paper pack with laminate layer, d) cloth pack.5 Propylene pack. The second factor had three levels storage period, 2, 4 and 6 months. Third factor: two storage condition.1) ambient condition and 2) controlled storage condition with 16◦C and 65% relative humidity. The results show that by increasing of seed storing period from 2 to 6 months the rate of germination was decreased from 84.87% to 79.25%. The higher rate of germination in the controlled storage condition with three layer paper pack was observed (88.62%) than ambient condition with Propylene pack (63.94%). Based on the results of the accelerated aging test by increment of storage duration from 2 to 6 months the rate of germination was decreased from 81.81% to 76.61%. The highest germination rate was related to three layer paper pack meanwhile the lowest germination rate was related to Propylene pack and cloth pack. The seed quality indices showed good statues in the controlled seed storage condition than ambient condition in both consecutive years. Also it was noticed that the highest and lowest final emergence seedling percentage was related to controlled storage condition with three layer paper pack (81.98% in the first year and 80.89% in the second year) and ambient condition with Propylene pack (62.31% in the first year and 62.08% in the second year). Generally it was noticed that storing the seed in three layer paper pack with controlled storage condition was suitable for preservation of soybean seeds.

Seed germination has been modeled extensively using hydrotime and hydrothermal time models. Variation in time to germination arises from variation in base water potential within a seed population that typically is modeled by a normal distribution. Here, the assumption of normality in the distribution of base water potential was examined by germinating seed of Phalaris minor, Amaranthus retroflexus and A. blitoides across a range of constant water potential (0, -0.2, -0.4, -0.6 and -0.8 MPa). Three statistical distributions of Normal, Weibull and Gumbel were compared to illustrate the relative variation of base water potential. The results showed that the estimated parameters of the hydrotime model developed on the basis of Weibull distribution had more certainty than other distributions (AICc=-322.2 for P. minor, AICc=-262.8 for A. retroflexus and AICc=-507.9 for A. blitoides). Values of shape parameter suggest that the base water potential is right skewed for three species (l=0.93 for P. minor, l=1.75 for A. retroflexus and l=2.21 for A. blitoides). Based on the Weibull hydrotime model, values of the hydrotime constant and water potential threshold for onset of P. minor seed germination were estimated to be 106.64 MPa h and -1.52 MPa, respectively, for A. retroflexus 20.47 MPa h and -0.86 MPa, respectively and for A. blitoides as 76.61 MPa h and -1.07 MPa, respectively. Due to the flexibility of the Weibull distribution, this model provides a useful method for predicting germination and determining the distribution of base water potential.