Effects of osmopriming and hydropriming on vigour and germination of China aster(Callistephus chinensis(L.) Nees.) seeds

The aim of this research was to evaluate the effects of osmopriming and different hydropriming treatments on the vigour and germination of China aster （Callistephus chinensis） seeds. Seed vigour and germination tests were conducted at 10, 20 and 30℃ in darkness for untreated, osmoprimed and hydroprimed seeds. The following parameters and categories of seeds and seedlings were evaluated： the mean germination time （MGT）, T10, T50, U75-25, U90-10, the percentage of germinating seeds （Gmax）, germination capacity, percentage of abnormal seedlings and dead seeds. The results showed that osmopriming accelerated seed germination to the largest extent and improved the uniformity of germination at 10 and 30℃. Among the hydropriming treatments the highest speed of germination was observed for seeds hydrated in 500 μL of water per 1 g of seeds for 48 h at 15℃. This treatment accelerated seed germination at 10℃ compared with the control. Osmopriming increased seed germination capacity at 30℃. None of the applied hydropriming treatments improved this parameter.

Amelioration of Salinity Stress in Maize Seed Germination and Seedling Growth Attributes through Seed Priming

Germination of seeds and growth of seedling respond to seed priming as priming can guard the damage of salinity stress. A study conducted in the net house of the Department of Agronomy, BAU, Mymensingh during the period from November 2012 to April 2013 investigated the ameliorative effect of seed priming on seed germination and seedling attributes of maize under various salinity stress conditions. The experiment consisted of five seed priming and four salinity levels (NaCl) and laid out in a Completely Randomized Design (CRD) with three replications. Seed germination and seedling attributes of maize varied due to salinity stress and priming. The highest seed germination (95.7%) was recorded when no stress was imposed under hydropriming (48 hours). The germination of seeds performed even well (92.3%) when treated with hydropriming (48 hours) and NaCl@0.25 dS&#183m-1 which was followed by hydropriming (24 hours) under no salinity imposed and NaCl@0.25 dS&#183m-1 salinity. Hydropriming for 48 hours without salt stress performed the best on number of leaves seedling-1 (8), shoot length (28.2 cm), root length (14.5 cm), fresh weight (100.8 g) and dry weight of seedling (50.3 g). The germination and seedling growth parameters were reduced with the increase in salinity levels irrespective of priming while all seed priming treatments showed ameliorative effects. However, reduction in seed germination and seedling attributes were minimal with hydropriming for 48 hours. The results revealed that priming of maize seeds could be used for amelioration of salinity stress and hydropriming for 48 hours appeared as the best seed priming treatment.

Seed Priming with MgCl_(2),CaCl_(2),and ZnCl_(2) as a Biofortification Based-Approach Induces Changes in Anise Seedlings Emergence

Aromatic and medicinal plant species having small seeds havefield emergence problems due to low nutrient supply.Therefore,Pimpinella anisum seeds were hydro and osmoprimed with 100 mM MgCl_(2),CaCl_(2),and ZnCl_(2),for 2,4,and 8 h each to compare their growth attributes during germination and seedling establishment stages.Nontreated seeds were used as control.Both hydro and osmo primed seeds were dried for 48 h before,they were sown in plastic trays in growth room conditions to see the impact of treatments on seedling emergence and growth.The maximum root length(12.90 cm),fresh weight(256.30 mg plant^(-1)),and mean emergence time(MET)were recorded from 8 h MgCl_(2) primed seeds.Similarly,the maximum(97.50,and 98.00%)emergence percentage was observed using 8 h MgCl_(2) primed seeds and nontreated seeds(control treatment).The evaluation of parameters like chlorophyll contents and electrical conductivity showed the 8 h MgCl_(2) priming as the optimum treatment.The evaluation of parameters like chlorophyll contents and electrical conductivity showed the 8 h MgCl_(2) priming as the optimum treatment.The result suggests MgCl_(2) priming worked synergistically and improved seed-ling growth attributes under greenhouse conditions.The chlorophyll content ranged 25.94–35.69 SPAD unit.The highest chlorophyll content was obtained from the seedlings obtained from 4 h CaCl_(2) treatment,which were statistically similar to the chlorophyll contents of the seedlings obtained after 8 h MgCl_(2) treatment and nontreated seeds(control treatment).All other treatments showed inhibition in the chlorophyll contents and growth attributes of the seedlings.In conclusion,MgCl_(2) osmopriming treatments were significantly promotive and better compared to hydro-priming and osmopriming treatments including control treatment in terms of anise seeds germination and emergence.

Can Hydro-Priming Improve Germination Speed, Vigour and Emergence of Maize Landraces under Water Stress？

We evaluated whether hydro-priming could improve vigour characteristics and seedling emergence of local maize （Zea mays L.） landraces compared to two commercial hybrids under water stress at the University of KwaZulu-Natal, Pietermaritzburg. Seeds from local landraces were produced and characterized according to kernel colour, white （Land A） and purple （Land B）, and compared to two hybrids, SC701 and SR52, which are popular amongst local farmers. Seeds from each variety were soaked in water for 0 hours （unprimed or control）, 12 hours and 24 hours, and germinated in a germination chamber at 25 ℃ for 8 days. Parameters measured included final germination, mean germination time （MGT） and germination velocity index （GVI）. Seedling emergence was performed in seedling trays, using pine bark wetted to 25% or 75% of field capacity （FC）, for 21 days in a temperature-controlled glasshouse （25 ℃day; 15 ℃night; 60% RH）. Parameters measured included final emergence, mean emergence time （MET）, root and shoot lengths, and leaf area. Priming landraces for 12 and 24 hours reduced MGT by 9% and 7%, respectively, compared to 5% in hybrids for both 12 and 24 hours priming. GVI of landraces was improved by 40% following 12 hours of priming. GVI of hybrids was 11% and 7% slower than landraces after priming seeds for 12 and 24 hours, respectively. Priming seeds for 24 hours improved emergence at 25% FC. Priming seeds for 24 hours reduced MET for all varieties. Priming seeds for 12 and 24 hours increased leaf area by 33.8% and 29%, respectively. Hydro-priming seeds for 12 and 24 hours, respectively, improved GVI, reduced MGT and improved emergence and MET of maize landraces under water stress. Performance of hybrid seeds remains superior to that of landraces even after seed treatment to improve germination and vigour. The positive response of landraces to seed treatment, and improved performance under water stress conditions, suggest that there is a need to identify genes for vigour in landrace maize.

Effects of different priming treatments and priming durations on germination percentage of parsley (Petroselinum crispum L.) seeds

The effects of different priming treatments and priming durations on germination percentage at different temperatures in parsley seeds were studied. The seeds were treated for 2, 4, 6 and 8 days with the PEG 6000 (–0.5 MPa, –1.0 MPa and –1.5 MPa), KNO3 (0.30 mol/L and 0.35 mol/L), Mannitol (0.50 mol/L and 0.60 mol/L) and hydropriming (12h, 24h, 36h and 48h) and unprimed (control). Germination studies were made at 5, 10, 15, 20 and 25°C. Percentage of germination at different temperatures was significantly affected by priming treatments. Hydropriming (12h, 24h and 36 h) and mannitol 0.60 mol/L at 2 day generally had the highest germination percentages. In general, the highest germination percentage with priming was determined at 10°C. It may be said that seed priming treatments increased seed germination percentage at both low and high temperatures. The highest germination percentages were observed in both hydropriming and mannitol treatments as compared with PEG and KNO3 treatments. The PEG and KNO3 (2 and 4 days) treatments were better than unprimed treatment in all of the temperatures.

Seed Priming and Tolerance to Salt and Water Stress in Divergent Grain Sorghum Genotypes

Tolerance to water and salt stress during germination and growth of agricultural species might have superior results when seeds are submitted to priming processes. The objective of the present study was to evaluate the use of hydropriming and hormonal priming with gibberellic acid (GA3) on the tolerance of divergent genotypes of sorghum to salt and water stress during germination and seedling growth. The genotypes analyzed were cultivar BRS 330 and lineage 201420, which are the most and least tolerant to water and salt stress, respectively. Sowing was undertaken under control (no stress), water stress (-0.6 MPa), and salt stress (20 dS·m-1) conditions, and the seeds were subjected to the following treatments: control-no immersion;hydropriming-immersion for 2 hours in distilled water;and hormonal priming-immersion in GA3 solutions, at concentrations of 50, 75, and 100 ppm, for 2 hours. After soaking, the seeds were dried for 24 hours at a temperature of 30°C ± 2°C. The variables analyzed were percentage and germination speed index, root and shoot lengths, and root/shoot ratio. The stress conditions analyzed negatively affected the two genotypes;however, the seeds that underwent priming processes improved the performance of the genotypes under salt and water stress conditions, especially when using seeds of the more tolerant genotype (BRS 330) subjected to hormonal priming at 100 ppm GA3 concentration.