نشریه تحقیقات بذر
پیاپی 36 (پاییز 1399)

To evaluation the effects of priming and different methods of seed dormancy breaking on germination and growth indices of castor (Ricinus communis L.), the experiment was conducted as factorial in a completely randomized design (CRD) with four replications in Seed Science and Technology Laboratory of Shahed University in 2016. Experimental factors were included seed scraping at four levels: control, removal of caruncle with standard cutting blade, chemical seed scraping with 98% sulfuric acid at 3 mM concentration for 5 minutes, and physical or mechanical seed scraping with standard blade and sandpaper and priming at five levels: control, seed treatment with 0.15% potassium nitrate solution for 24 hours, hot water at 70 °C for 15 minutes, gibberellic acid solution 300 ppm for 24 hours and cold chilling in cold water for 24 hours. Results showed that interaction between priming and scraping on root length and number of normal seedlings and the effect of scraping on all studied indices were significant. The highest germination percentage (90 percent) and the lowest mean germination time (0.16 day) were obtained in caruncle removal treatment, which shows that as the percentage of germination increases, the time required for germination decreases. Shoot length, root/shoot length ratio, seedling fresh weight and seed vigor weight index in caruncle removal treatment showed significant increasing compared to control. In general, it can be concluded that caruncle appendage is the most important factor in preventing germination and growth of this plant and by removing it, all indices increase significantly.

In order to evaluate the effect of sowing date and different amounts of nitrogen and phosphorus fertilizer on seed germination characteristics of Lallemantia (Lallemantia royleana Benth.), a factorial experiment in a randomized complete block design (RCBD) with three replicates was conducted in Research Fram of Medicinal Plant Research Center of Shahed University during 2013-2014. Factors were: sowing date in two levels: autumn and spring and chemical fertilizer at three levels (without fertilizer, half amount of fertilizer (23 kg/ha pure N+ 50.6 kg/ha pure P2O5) and all amount of fertilizer (46 kg/ha pure N+ 101.2 kg/ha pure P2O5). Results showed that the effect of sowing date on germination percentage, catalase activity during grain filling, percentage of nitrogen and phosphorus and mucilage percentage, was significant except in seed weight. Effect of chemical fertilizers on all traits was significant. The intraction effect of sowing date and fertilizer was significant on catalase activity, percentage of mucilage, percentage of nitrogen and phosphorus, but was not significant on germination percentage and seed weight. The highest seed germination percentage (74.8%) related to sowing in autumn which showed an increase of 11.6% compared to sowing in spring. The highest seed germination percentage was related to all amount of fertilizer (88.6%) which showed an increase of 73.4% compared to no fertilizer. In general, autumn sowing date and fully application of chemical fertilizers resulted to higher seed quality.

n order to investigate the phenological characteristics of Mastar (Sclorhachis leptoclada Rech.f) in natural habitat and to determine its cardinal germination temperatures, the study was conducted in 2018 in one of its natural habitats in South Khorasan province located in Ark protected area in in Research Laboratory of Islamic Azad University of Birjand. Treatments were seven treatments consisting of temperatures of 2, 5, 10, 15, 20, 25 and 30 °C with four replications in a completely randomized design. Measured traits included germination percentage and rate, average germination time, length and fresh weight of radicle and plumule and dry weight of seedling. Results of ecological study of the habitat showed that the habitat was mountainous and rocky with sandy soil and acidity of 8.18 with an average annual rainfall of 150 to 200 mm. The study of phenological stages of Mastar plant also showed that this plant needs 138 days and 1393.6oC during the growth stages. Regression analysis of seed germination data showed that, minimum, optimal and maximum germination temperatures were determined at 5, 10 and 30 °C, respectively.

Common barberry is an important species due to its high medicinal and nutritional value, prevention of soil erosion and use in green areas. So, its seeds were collected from Kelardasht, Mazandran provice. Seeds were affected by different treatments such as salicylic acid, gibberellic acid, ascorbic acid and hydrogen peroxide and germination indices such as percentage, speed, time and vigor index were evaluated. Experiment was carry out based on randomized complete blocks with four replications. According to the results of the study, common barberry seeds under the influence of ascorbic acid, salicylic acid and hydrogen peroxide treatments, were better than control in all physiological indices. However, in gibberellic acid treatment with increasing concentration, growth rate and germination increased and the best results were obtained at 1000 parts/million concentration. Ascorbic acid treatments with 200 mg.L-1 concentration showed the lowest rate of germination and growth. Therefore, with the exception of gibberellic acid, all treatments were not suitable as agents for improving germination and establishment under environmental stress. But gibberellic acid treatment with a concentration of 1000 parts/million can be suitable treatment to improve germination. Therefore, due to the high medicinal value of this species, it is suggested that other dormancy breaking treatments be tested in order to select the best and most cost-effective treatment.

Fertilizer application management, especially farmyard manure, is one of the most important parts of canola (Brassica napus L.) production. In this study, the effect of farmyard manure extracts on germination characteristics and vegetative growth of canola cultivars in laboratory condition, were studied in Ramhormoz. Treatments were included eight canola cultivars (Hayola 50, Hayola 76, Hayola 308, Hayola 401, Hayola 420, Hayola 4815, Dalgan and Safi 6) and farmyards manure extract included poultry, sheep and cattle fertilizers extract in 50% volume with control treatment (distilled water). Results showed that effects of farmyard manure extract on germination and growth seedlings of canola was significant at 1% probability level. The highest coefficient of germination velocity related to cattle fertilizers (0.11) and control (0.1175) treatments. Beginning of germination in sheep fertilizers extract treatment (2.833) compared to control (1.292) was faster and the most end of germination was observed in cattle fertilizer extract treatment (11.58). Poultry fertilizers extract was inhibitory effect on germination and other attributes of canola. In general, it was concluded that poultry fertilizer compared to sheep and cattle fertilizers, had negative effect on all traits.

Seaweed extract (Ascophyllum nodosum) can play an effective role in growth and germination due to having plenty of nutrients and plant growth regulators. In order to evaluate the effects of seaweed extract on germination indices of lentil cultivars, a factorial experiment was conducted in 2015 on the basis of completely randomized design with three replications at Khatam Al-Anbia University of Technology in Behbahan. The experimental treatments consisted of four seaweed extracts (0, 2.5, 5 and 7.5 %) and three cultivars of lentil (Robat, Gachsaran and Kimia). Results showed that 5% extract treatment, resulted in significant increase in germination percentage (15.9%), plumule length (10%), plumule dry weight (2%) and consumed endosperm (15.3%) compared to control. Among the studied cultivars, Kimia had a significant decrease in all studied traits compared to other cultivars. Interaction effect of seaweed and lentil cultivars showed that Rabat and Gachsaran cultivars in all levels of seaweed extract led to significant increase in germination rate, radicle length and radicle dry weight. In Kimia cultivar, 5 and 7.5% seaweed extract led to significant increase of germination rate, germination vigor, radicle length and radicle dry weight. According to the results of this study, the use of seaweed extract to improve germination conditions in lentil cultivars (Robat, Gachsaran and Kimia) is recommended.