نشریه علوم و تحقیقات بذر ایران
سال دوم شماره 1 (بهار و تابستان 1394)

In order to evaluate the effect of matrix priming on some germination traits improvement of three soybean commercial cultivars seeds produced under parent plant drought stress, a field and laboratory experiment conducted as a factorial respectively based on randomized complete block and completely randomized design by four replications in Seed and Plant Improvement Institute(SPII) and the seed analysis laboratory of Seeds and Plant Certification and Registration Institute at Karaj. Three soybean commercial cultivars, L17, Hamilton and Williams seeds produced under parent plant drought stress by irrigation after 50, 100, 150 mm evaporation from A class pan evaporation. Then, seeds by 1 to 4 weight ratio of sterilized compost, vermiculate, perlite and zeolite solid matrices in distilled water matrix primed and not matrix primed seeds were control. By standard germination test, final germination percent, normal and abnormal seedlings percent, mean germination time, coefficient of velocity of germination, mean daily germination and daily germination speed determined. Results revealed, drought stress imposed on parent plant caused final germination, normal seedlings percent and germination rate indices decreased and abnormal seedlings percent and mean germination time increased. Under drought stress conditions L17 cultivar seeds had more final germination percent and less normal seedlings percent as compared with other studied cultivars. Totally, matrix priming caused produced under drought stress conditions seeds related to germination studied traits improvement and by increase drought stress intensity this improvement was more obvious. Also, vermiculate, zeolit, compost and perlite solid matrices respectively had more improvement effect. Hamilton cultivar seed produced without stress and under drought stress conditions, matrix primed by vermiculate solid matrix had the most improvement.

Moisture deficiency and soil salinity are two inhibiting factors that affect the forage production in rangelands, so that moisture and salinity are the main barriers for plants reproduction at the seed germination time. Therefore, in this study, the effect of different level of salinity and moisture on the germination characteristic in Salsola crassa was conducted. Factorial experiment in a randomized complete block design with four replicates was performed. Three common salts which are found in rangelands including: Calcium Chloride (CaCl2), Potassium Chloride (KCl), Sodium Chloride (NaCl) and a combination of three salt treatments at six levels containing: 5, 10,15,20,25 and 30 g/l were used under laboratory conditions. Also distilled water was used as control. Drought stress effects were studied at the greenhouse condition in which treatments was included irrigation periods with an interval of three days in four replications. Investigated characteristics were including: percentage and speed of germination, root and shoot length, height and aerial biomass. The results showed that all seedling characteristics changed under increasing salinity and drought stress levels (P<0/01). Salinity levels showed significant effects on germination percentage and velocity, seedling root and shoot length. Drought stress, significantly affected plant height and aerial biomass (P <0/05), but increasing in stress level, resulted in increasing of root length (P<0/01).The irrigation period of 18 days interval showed the lowest plant height and production, and the highest root length. Overall, drought stress's 15 and 18 days interval treats and also, salinity stress's CaCl2 with 30 g/l concentration had the most negative effect on investigated characteristics.

An invitro experiment with four replications by Randomized Complete Design, was performed in Laboratory to compare the response of seeds of medicinal plants to salinity. Plantago spL., Alyssumspp,Portulaca oleracea, Sesamum indicum, Origanum majorana, Trigonella foenum,Anethum graveolens,Melilotus officinalis,Trachyspermum ammi,Cuminum cyminum, Lactuca sativa and Lallemantia royleana were conducted during 2010. In each Petri (Replication) 100 seed were cultivated. The treatments were 0,25,50,75,100,150, 200,250,300,350,400 and 450 ds/m NaCl. When water of Petri dish, relatively evaporated, the irrigation was conducted in field capacity. Results showed that plants of PlantagospL., Lallemantia royleana   andAnethum graveolens were tolerate up to 100ds/m, Cuminum cyminum, Origanum majoran, Melilotus officinalis and Trachyspermum ammi were tolerate up to 200ds/m, Lactuca sativa and Sesamum indicum were tolerate up to 250ds/m and ofPortulaca oleracea, Alyssumspp and Trigonella foenum were tolerate up to 450ds/m. Increase of concentration of NaCl results that germinated seeds and biomass of them, were decrease.  Portulaca oleracea, Alyssumspp and Trigonella foenum in many places were the most tolerance.

Cold and tropical Vetch (Vicia villosa and Vicia pannonica)are an important plants which did not do any experiment about quantification of them germination reaction to temperature. Thus, a CRD experiment performed in seed research laboratory of Urmia University with four replications which temperature treatment were eight levels of temperature as: 1, 3, 5, 10, 15, 20, 25, 30, 35 and 40 º C. Results revealed that temperature had a significant effects on germination rate and it’s percent and segmented model estimated greatly cardinal temperature (base, optimum and ceiling temperatures). Germination rate of Vicia. Pannonica in equal and less than -7.6 and equal and higher than 40.76 ºC stopped, though this thermal range for V.  villosa was equal and less than -3.8 and equal and higher than 41.2 º  C, respectively. R max were 0.027 and 0.033 h-1 for V. pannonica and V. villosa respectively. Also, results emphasized that both of Vicia species can be geminate in less than zero temperature and in V. Pannonica the base temperature was fewer than V. villosa, so, germination percent and its rate increased by upgrading in temperature to optimum temperature. Therefore, both Vicia species can geminate and emergence in  extended range of environmental thermal from -7.6 to 40.76 º C for V. Pannonica and -3.8 to 41.2 º  C in V.  villosa and thus recognized as a forage crop with acceptable production for various season and climate.

This experiment was conducted in order to evaluate accelerated agingtimeeffect and various size and shapes of hybrid corn, cv. single cross 704 seeds on some germination and seedling vigor traits in 2014 in Seed and Plant Certification and Registration Institute(SPCRI) at Karaj. Experiment was done as a factorial experiment based on  completely randomized design by four replications. In order to seeds size and shape grading, three round sieves by 5.5, 6.25 and7 mm holes diameter size were used for round and flat shapes and medium size separation respectively. Seeds under taken accelerated ageing conditions at 41 centigrade degree temperature and 100 relative humidity at 4 ageing times, 72, 96,120 and 144 hours. Then standard germination test was conducted and normal seedlings percent and mean germination time and seedling weight and length vigor indices were measured. Results indicated that aging time and seed size and shapes effects on determined germination and vigor indices were significant. Aging time for 144 hours caused significant decrease in normal seedlings percent compared to other ageing times and 120 and 144 hours aged seeds had highest mean germination time and then 96 and 72 hours aged seeds arranged respectively. Only 144 hours aging time caused significant seedling length vigor index decrease in comparison to other aging and highest and lowest seedling weight vigor index investigated at 72 and 144 hours aging times respectively. Also, highest normal seedlings percent and mean germination time related to flat shape and medium size seeds and highest and lowest seedling length and weight vigor indices amounts belonged to flat and round shape seeds respectively comparison indicated that normal seedling percentage, seedling length and weight vigor indices in three seed sizes had significant different and the highest and lowest rates were in flat and round respectively.

To study the effect of different hormone combinations on breaking dormancy and germination of Black Zira, 27 treatments consisted of three hormone, gibberellic acid (80, 100, and 120 μm), Thidiazuron (4, 6 and 8 μm) and benzyl adenine (5, 10 and 15 μm). Factorial experimental with three replications in a randomized complete block design was carried out. Seedling length, seedling fresh weight, seedling dry weight and the total percentage of germination were measured and seedling vigor index, fresh weight index, and dry weight index were calculated. Analysis of variance showed the significant differences between the effect of ecotype × combination × Hormone level for fresh weight, total percentage of germination and vigor index. Comparison of means for ecotype × combination × level effect showed the total percentage of germination and vigor index were highest for sixth level of GA × BA combination in Hormozgan ecotype and fresh weight was highest for fifth level of TDZ × BA combination in Semnan ecotype. Mean Comparison of ecotype effects showed that the dry weight index was the highest in Semnan ecotype and the Mean Comparison of level effects showed that the dry weight index was highest in fourth levels (6 μm TDZ and 5 μm BA and 100 μm GA). The result showed that hormones levels and combinations were suitable for seed germination in this experiment. Hormozgan ecotype had the best germination at GA × BA combination.