جستجوی مقالات مرتبط با کلیدواژه « قوه نامیه » در نشریات گروه « زراعت »

This research has been done in a completely randomized design and using a factorial experiment with three 3 replications in Date palm and Tropical Fruits Research Center in Ahwaz for two years (2018-2019) to evaluate different methods of date pollen grain maintenance. Factors include type of pollen (fresh pollen, dry pollen, fresh strands, dry strands, and full male spahte cv. Ghannamy, storage environment (room temperature, refrigerator (+4 degrees Celsius) and freezer (-20 degrees Celsius)) and storage time (3, 6, 9 and 12 months). Germination test of pollen grains is performed in liquid culture medium containing 8% sucrose and 50 mg l-1boric acid using a light microscope. Results show that the interaction effects of storage environment× type of pollen and storage environment × storage time on pollen viability have been very significant and dried pollen and dried strand pollen in freezer and refrigerator and during storage period of about one year have given the most appropriate results. Fresh pollen, fresh strand pollen, and whole spahte pollen, due to their high humidity content, lost their viability in a short time. Therefore, in order to preserve the pollen and maintain its vigor and viability in the long run, it is absolutely necessary to dry the strands or pollen in order to reduce their moisture content and increase their shelf life.

One of the valuable species of Iranian forests in Iran and Turan is the wild pistachio species and they have high economic value. Seed production is one of the important topics in forestry and rehabilitation and afforestation programs with seeds and seedlings, and therefore the need to obtain the necessary information about the quality and quantity of seeds of this species is felt more than ever. First, to collect seed samples, a land unit map was prepared. After superimposing the direction, slope and elevation maps, the pistachio seeds were collected from the designated areas. Seeds were collected from 23 sampling areas. Percentage of viability, germination rate, germination value and mean day of germination for each seed mass based on the formulas and calculations of seed testing and the rules of the International Seed Testing Association (ISTA) was determined. The results showed that the direction, elevation and slope factor at 1% level had a significant effect on viability, germination value, and mean day of germination and seed germination rate. The results of comparing the means showed that at high elevation and in the direction of north and south and a slope above 60%, pistachio seeds had the highest percentage of viability. Also, the results of comparing the mean value of pistachio seed germination showed that at low elevation, north direction and slope of 0-30%, pistachio seed germination value was high. Mean day of germination in the south direction and slope above 60%, the highest mean day germination and also in two elevation and east and west and slope above 60% had the highest germination rate of pistachio seeds.

Purple nutsedge causes severe damages to vegetable crops in Jiroft, Kahnooj and Birjand. In order to evaluate the effects of high temperature and time of exposure to high temperatures on various ecotypes of purple nutsedge tubers, a factorial experiment was conducted based on randomized complete block design with 3 replications in the Research greenhouse of Birjand University, Iran, in 2016. Experimental factors consisted of 3 ecotypes (Jiroft, Kahnooj and Birjand), different temperatures from 40 to 60°C with 5°C increments, and exposure time including 1, 2, 4, 8, 16, 32 and 64 hours. Results indicated that at all exposure times, 40°C temperature did not affect the growth characteristics of purple nutsedge, while at 45 °C, increasing the exposure time decreased the growth characteristics of purple nutsedge. Three-parameter logistic model estimation showed that  tuber viability (T50) at 45 °C in Jiroft ecotype was 14.64 hours, it decreased to 5.01 hours  at 50 °C. T50 was about 66% lower than for 45 ° C, but it was 19.76 hours in Kahnooj ecotype at 45 °C, while at 50 °C, this parameter decreased to 2.73 hours (86.2%). T50 of Birjand ecotype at 45 °C was 12.90 hours, but at 50 °C, the tubers viability reduced and T50 was 8.91 hours (31% decrease). Results of this research could have an important role in controlling purple nutsedge in vegetable fields.

One of the valuable species of Iranian forests in Iran and Turan is the wild pistachio species and they have high economic value. Seed production is one of the important topics in forestry and rehabilitation and afforestation programs with seeds and seedlings, and therefore the need to obtain the necessary information about the quality and quantity of seeds of this species is felt more than ever. First, to collect seed samples, a land unit map was prepared. After superimposing the direction, slope and elevation maps, the pistachio seeds were collected from the designated areas. Seeds were collected from 23 sampling areas. Percentage of viability, germination rate, germination value and mean day of germination for each seed mass based on the formulas and calculations of seed testing and the rules of the International Seed Testing Association (ISTA) was determined. The results showed that the direction, elevation and slope factor at 1% level had a significant effect on viability, germination value, and mean day of germination and seed germination rate. The results of comparing the means showed that at high elevation and in the direction of north and south and a slope above 60%, pistachio seeds had the highest percentage of viability. Also, the results of comparing the mean value of pistachio seed germination showed that at low elevation, north direction and slope of 0-30%, pistachio seed germination value was high. Mean day of germination in the south direction and slope above 60%, the highest mean day germination and also in two elevation and east and west and slope above 60% had the highest germination rate of pistachio seeds.

Camelthorn (Alhagi maurorum) has a high tolerance to salt and water stresses, and its forage quality is greater than cereal straw and is equal to alfalfa. Seeds of camelthorn do not germinate easily due to the hard seed coat. Therefore, camelthorn cultivation as an agricultural crop needs more research, especially on breaking seed dormancy and increasing germination. Despite numerous studies about camelthorn as a weed, there are few studies on evaluating agronomic factors of camelthorn as a field crop. Hence, in this study, some aspects of germination and salinity tolerance of camelthorn were examined.

In this research, different aspects of camelthorn germination were examined at the National Salinity Research Center in 2018. In the first experiment, different pretreatments including control, sandpaper, hydro-priming, hot water, and sulphuric acid were assessed. With the selection of sulphuric acid as the best treatment, varying durations (0, 5, 10, 15, 20, and 25 min) and concentrations (98% and 75%) of sulphuric acid priming were compared in the second and third experiments. In the fourth experiment, the seeds collected in 2018 were compared with the seeds collected in 2017 and 2016. The effect of different salt stress levels (0, 6, 12, 18, 24, 30, and 36 dS m-1) was evaluated on camelthorn germination and early growth in the fifth experiment. In the sixth experiment, lighting regimes including continuous dark, continuous light, and an alternative period of dark- light were examined and in the seventh experiment sibling factors (together and individual seeds) were evaluated. Seed germination and seedling length were calculated and salinity tolerance threshold levels and 50% reduction threshold were estimated.

The results of the first experiment showed that the highest germination percentage was obtained in sulphuric acid priming (56.6%), which was six folds greater than the control. In the second experiment, it was shown that the highest germination percentage (81.1%) and seedling growth (5.7 cm) was observed in sulphuric acid priming 98% for 25 min. Important note was that these results were related to domestically produced sulphuric acid, and the highest germination and seedling growth were observed in 75% concentration for the imported sulphuric acid. In the fourth experiment, it was found that at least 3 years of seed longevity had no significant effect on seed germination. Considerable losses in germination and growth were observed from 30 dS m-1 salinity level; however, germination did not completely stop even at 36 dS m-1 salinity. In the sixth and the seventh experiments, it was found that there were no significant differences between seeds germination in the continuous dark, continuous light, and an alternative period of dark- light as well as between individual and together seeds. So, camelthorn seed is not photoblastic and had no negative sibling factor.

Generally, it was concluded that the best method for improving germination is priming with sulphuric acid 98% (internal) or 75% (imported) for 25 min. According to achievement of high germination in sulphuric acid pre-treatments (chemical scarification), it seems that seed dormancy in camelthorn is presumably physical. Furthermore, although the salinity tolerance threshold of this plant is estimated 14.2 dS m-1, it can germinate minimally even in very higher salinity. Light salt stress not only decreases the germination of this plant but also is necessary for growth promoting. Based on the high salinity tolerance of camelthorn in the germination stage, its cultivation in haloculture systems is recommended for more investigation.

1- Sulphuric acid 98% priming for 25 min led to breaking seed dormancy and acceptable camelthorn germination. 2- In moderate salinity, germination was not significantly changed and seedling growth was promoted compared with the non-stress conditions. 3- Salinity tolerance threshold level of camelthorn was estimated 14.2 dS m-1.

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.

In order to investigate the effect of seed aging and plant density on yield and yield components of wheat (CV. Chamran), an experiment was conducted in 2010-2011 cropping year in Agricultural Research Center of Safi-Abad (Dezful).The experiment was factorial with randomized complete block design with three replications. The treatments consisting of seed aging in five levels (control, 48 , 72 , 96 and 110 hr) and plant density (300 , 350 , 400 and 450 plant m2).The results showed that seed aging decreased field indices as grain number per spike, spike density, harvest index, biological and grain yield. The mean comparison of aging simple effect showed that the highest (4179 kg ha-1) and the lowest (3166 kg ha-1) grain yield belonged to control treatment and treatment with 110 hr seed aging, respectively. The effect of plant density on the traits such as spike density, 1000-grain weight, biological yield and harvest index was significant, too. In addition, the correlation between grain yield and biological yield, harvest index, spike density and 1000-grain weight was positive. In this study, observed that temperature and seed aging duration are the most important factors that influence the occurrence and progression of seed aging. Hence, the development of seed aging with increasing temperature and its implementation duration is predictable.

In order to evaluation of most suitable seed moisture content at harvest for production of high viability and vigor seed of two Oil-seed rape cultivars، this study was conducted during 2000- 2009 in Dezfoul. Therefore samples of Hyola 401 and Hyola 308 cultivars seeds by 10%، 15%، 25% and 35% moisture content harvest from seed multiplying field and at central seed analysis laboratory of Seed & Plant Certification & Registration Institute (SPCRI) in Karaj by conducting standard germination test، some seed quality indices like as primary and final germination percent (seed viability)، normal and abnormal seedling number، mean daily germination speed (MDG)، daily germination speed (DGS)، seedling length، fresh and dry seedling weight and seedling vigor index (seedling dry weight × viability) measured. Obtained data by 2×4 factorial experimental based on completely randomized design with three replication، combine analyzed and results revealed that expect of normal and abnormal seedling number، all measured indices affected by studied factors and primary and final germination percent، mean daily germination speed (MDG)، fresh and dry seedling weight and seedling vigor index (seedling dry weight × viability) affected by cultivar × seed moisture content × year interaction. Highest primary and final germination percent obtained at 15 percent seed moisture content for both cultivars. Also the highest rate of mean daily germination speed (MDG)، fresh and dry seedling weight and seedling vigor index (seedling dry weight × viability) obtained at 15 percent seed moisture content for both cultivars. In addition to، primary and final germination percent of Hyola 401 was more than Hyola 308. This result revealed that seed quality and its various aspects affected by environmental factors and seeds harvested at 15 percent moisture content have highest seed quality.

Seed samples of three oil-seed rape cultivars SLMO46, Orient and Zarfam (Regent×Cobra) with 35, 25 and 15% moisture contents were provided from seed production fields. Cortrolled deterioration test was conducted in laboratory by maintaining seeds at 40, 45 and 50°C for durations of 12, 24 and 48 hours. Analysis of data on different seed quality assessment parameters showed that except coefficient of velocity of germination, other traits were affected by deterioration treatments. Seeds of cultivar Orient had the lowest viability, seedling vigour and other related traits at 50°C for 48 hours treatment. The dioriorated seed were sown in field and some characteristics such as seedling emergence speed, field emergence index, seedling height, seedling fresh and dry weight and seedling vigour index were assessed. Analysis of data showed that only seedling fresh weight and seedling vigour index were not affected by the effect of year. Interaction effects of cultivar, temperature and duration of seed deterioration were significant for all measured characters. Seeds of Orient cultivar deteriorated at 50°C for 48 hours had the lowest field emergence speed and field emergence index. Study of correlation between different traits assessed in laboratory and field indicated that except seedling fresh weight, other field traits correlated to the final germination percent and other laboratory traits. The results of the present study revealed that application of controlled deterioration test has the potential to evaluate seed quality and seedling emergence and establishment of oil-seed cultivars in field

In order to determination of optimum quantity of seed pelleting materials due to sugar beet monogerm seed size. This study was carried out in seed technology department during 1997-1998. Monogerm cultiver 9597 seed lot (300kg) was firstly graded by 7 round sieves and then 7 rectangle sieves graded each bound. Some factors such as germination, monogermity and proportionate seed pelleting materials due to seed size evaluated of categories seven bounds contained 70% of total weight which had hormal seedling carsteristies. All categories nacked seed lots were coated with 1/1, 1/2 and 1/3 ratio of seed weighty pelleting materials composition, respectively. Germination, monogermity and uniformity and some other factors were determined on pelleted seeds. Results showed that the over using seed pelleting material (1/3) had negative effect on germination and uniformity. This results indicated that tooptaind acceptable germination and uniformity in emergence the proportion of seed pelleting material and seed weight should be 1/1 respectively. The results indicated suitable germination and uniformity in emergence created by 1/1 ratio of seed pelleting material and seed weight