بنیه

The uniformity and emergence percentage of seeds have an importance role on the yield and quality of crops in the field. The aim of this research was to evaluate the seeds emergence and seedlings of three populations of the lanceleaf thyme species (Thymus lancifolius Celak) by Priming methods. In order to evaluating seed emergence and seedling vigor of three populations of (Thymus lancifolius Celak), a factorial experiment based on completely randomized design with three replications was conducted in Research Institute of Forests and rangelands, Tehran, Iran in 2015-2016. The factors A was including: three populations of (Thymus lancifolius Celak) and factor B were seven treatments as follows: osmopriming (PEG 0.3 and 0.6Mpa), hormonal priming (250 and 500 ppm of Gibberellic acid), Matrix priming (Vermicolit 1%) hydropriming (distilled water) and control. The emergence characteristics including of seed emergence percentage and speed of emergence, root and shoot length, vigor index, seedling fresh and dry weight were measured. The mean comparison three populations showed that all emergence traits of population 13490-Arak were more than the other two populations. The maximum emergence percentage as (81.19) obtained using vermiculite treatment. using vermiculite, seedling Fresh weight, (578.8), dry Weight, (47.78), dry matter percentage (7.82%) were more than other treatments. High speed of emergence observed as (5.82 seeds per day) with effect of Gibberellic acid 250 ppm. Regarding to result of this research work, it was proved that two Priming technique as Matrix priming (Vermiculite) and Hormonal priming (Gibberellic acid) were effective method compare with other method. Therefore these two methods are recommending for domestication and optimum establishment of medicinal plant of (Thymus lancifolius Celak).

Production of high-quality seeds to stabilize crop yield is an important challenge for breeders. One of the most important answers to this challenge is to clarify the molecular mechanisms associated with seed vigor characteristics. Functional proteins of Cupin superfamily are among the molecules in signaling pathway. Previous research has shown that in maize, a storage protein similar to the functional Cupin superfamily protein called ZmGLP is effective in seed germination. However, in the previous experiments, suitable indicators were not used to assess seed vigor and its relationship with field establishment. So, it is needed to study the performance of ZmGLP in predicting field emergence to complete the previous research.

An experiment was performed on 14 samples of commercial inbred maize lines. In this experiment, in addition to the laboratory evaluation of seed germination, field indices of physiological seed quality including the percentage of seedling emergence in the field, time to 50% seedling emergence, time to 90% seedling emergence, seedling dry weight, seedling height and coefficient of variation of seedling height was also assessed. In the polymerase chain reaction, two pairs of primers (CF / CR primers and IDF / IDR primers) were used to identify the DNA sequence of the Cupin.

The results show that the seeds were different in terms of physiological quality. The lowest percentage of germination in laboratory was related to K1264/1, while the lowest physiological quality of seeds in field indices was observed in K1263/17. The molecular test confirmed the presence of the desired allele at the InDel9 site of vigor-related genes in the three samples of B73, K1264/1, and K1264/5-1, but no amplification band of the InDel9 site was observed in all K1263/17 seed samples. Due to the fact that line K1264/1, which had the lowest germination percentage in the laboratory, had an amplification band at this related site to vigor, it is not enough to rely on the results of the laboratory germination test to investigate the relationship between this gene and seed vigor. The field emergence test and seed vigor test that have a good prediction of field emergence must be used in these studies.

According to the results of this experiment, molecular tests with functional markers based on Indel9 can be used to accelerate the evaluation of vigor, especially when the breeder is breeding a new line or hybrid. It is a useful, rapid, and effective molecular method to predict seed emergence in the field and screen the lines to ensure the genetic strength of the germination of the lines, especially in the temperate germplasms of corn. Finally, it is necessary to determine the threshold of low vigor during seed quality investigation in different cultivars, and relationship between the presence or absence InDel9 site should be considered in future research.

Highlights:

1- The feasibility of using molecular markers to determine the seed vigor of corn lines in the field was studied and optimized for the first time.
2- The results of physiological quality assessment of seeds in the field for the studies related to the relationship between molecular markers and seed vigor were exploited for the first time.
3- The Indel9 site and molecular markers related to seed vigor in the field were introduced.

Providing important and effective elements such as zinc and boron- especially in areas where the soil for some reason cannot meet the needs of the plant- will be a good solution to improve seed and seedling quality and nutrition, and community health status. A considerable part of the wheat producing regions in the country are faced with late season haet during seed development stages. Thus, the present study will investigate the effect of heat stress and mother plant nutrition with zinc and boron micronutrients on seed deterioration and physiological quality of wheat seedlings.

In a field experiment, wheat seeds were planted on two suitable planting dates (November 20) and late (January 5) to apply late-season heat stress during the seed development stage with three replications in Ramhormoz, Iran. The nutrition of mother plants with zinc and boron elements was done at three levels (nutrient-free and application of zinc and boron) as a foliar application. After harvest, the seeds were transferred to the laboratory and membrane integrity of seed cells was investigated using an electrical conductivity test as an indicator of deterioration. Another part of the seeds was planted in a factorial pot experiment based on RCBD with three replications to evaluate the quality of seeds and seedlings in the greenhouse.

The results showed that exposure of seeds to heat stress during development reduced seed quality as well as seedlings so that the cell membrane in the seeds produced under heat stress conditions was damaged and their electrical conductivity increased by 19%. Also, these seeds showed more sensitivity to deterioration. The percentage of seedling emergence in the stressed seeds decreased by 21.66%. Heat stress also reduced seedling quality indices such as chlorophyll content, shoot dry weight, and root dry weight. Application of zinc and boron on the mother plant not only led to improved quality of seeds and seedlings under normal conditions but also the negative effects of heat stress on seed and seedling quality were reduced. There was a significant negative correlation between the seed electrical conductivity test and qualitative parameters. Therefore, the use of this test is recommended to determine the quality of seeds, especially seeds produced under late-season heat stress conditions.

Noting the negative effect of heat during seed development on seed quality, planting dates should be adjusted as much as possible so that the seed development stage does not coincide with the late-season heat stress. Due to the beneficial effects of using zinc and boron in the mother plant on many traits related to the quality of seeds and seedlings, their application- especially zinc- in soils with deficiency or the possibility of heat stress at the end of the season is recommended.

factorial experiment based on completely randomized design with three replications was conducted in greenhouse of Research Institute of Forests and Rangeland, Tehran, Iran in 2015-2016. The levels of factor A were: three populations of (Thymus daenensis) originated from Lorestan, Markazi and Isfahan province, Factor B were: osmopriming (PEG 0.6 and 0.9 Mpa), hormonal priming (250 and 500 ppm of Auxin), Matrix priming (Zeolite1%), hydropriming (distilled water) and control. The primed seeds were sown on pots and growing in greenhouse. Seed emergence characteristics including of percentage and speed of emergence, root and shoot length, vigor index, seedling fresh and dry weight were measured. The mean comparison three populations of thymus showed that maximum emergence percentage and speed of emergence as (76%, 13.17/sprout/day) were observed in population of 1110-Lorestan.  The effect of treatments on the populations showed that The maximum percentage of emergence and speed of emergence (88%, 15.39/ sprout/day), seedling length  and vigor index (57mm,50), were obtained with priming technique (PEG 0.9 Mpa) in the population of 1110-Lorestan. Also percentage of emergence and speed of emergence (83%, 15/sprout/day) and seedling length, vigor index as (59 mm, 49) of the population of 110-Lorestan were maximum with matrix priming (zeolite). Regarding to result of this research work, it was proved that two priming technique including: Osmo-priming (Polyethylene glycol) and Matrix priming (perlite) were effective method compare with other method. Therefore these two method are recommending for domestication and optical establishment of medicinal plant.

Pseudo Chamomile (Tripleurospermum sevanense) is medicinal and aromatic plant. This plant is growing in natural habitats of Iran. In this study, emergence enhancement of seed and seedlings vigor of three populations, were compared with priming technique and pre-chilling treatment. A factorial experiment based on randomized complete design with three replication and six treatment was conducted in laboratory (2010) and greenhouse (2011) in Research Institute of Forests and Range Lands. The priming treatments including: [GA3 (125 and 250ppm), KNO3 (0.5 and 1%), distilled water (control)] and moist chilling at 4°C. In laboratory experiment, the results of treatments on seed germination characteristics of 17952-Fars population showed that maximum germination (96%), fresh weight (97.33 mg) were obtained with effect of potassium nitrate. With effect GA3, speed of germination (18.7 sprout/day) Vigor index (127.91) were more than control and other treatments, meanwhile in greenhouse experiment, effect of treatments on seedling appearance characteristics of above population showed that potassium nitrate treatment had more significant effect on seedling appearance percentage (85.55%), seedling length(103/46mm), seedling vigor index (88.35) control and other treatments. On the base of results, it is recommended for cultivation and domestication of medicinal species, especially in spring, priming technique would e used for uniform germination and seedling appearance

Drought is a meteorological event occurring due to the absence of rainfall in a period of time. With the occurrence of drought stress, the water available to the soil is reduced, but the loss of water through evapotranspiration increases continuously. Drought can be effective in reducing the rate of germination and germination percentage, and inadequate The necessity of moisture for germination in soil layers and consequently drought stress in seedling stage is one of the important factors in the lack of desirable seedling establishment in arid regions. Considering the importance and role of medicinal plants in different industries, as well as lack of resources Water and abundance of arid regions in the country, it is necessary by applying techniques on the seeds of these plants, proper management of the production and cultivation of these valuable species, and Increase their performance. The purpose of this study was to investigate and use nanosilver particles in increasing or improving the indices of germination of two important species of Thymus. Seeds of Thymus genotypes Thymus daenensis Celak and Thymus vulgaris L. from Isfahan Seed Packers Company were obtained. This study was carried out in a factorial experiment in 2009 in a completely randomized design with three replications in University of Kashan. Drying treatments were considered at four levels (0, 0.3, -0.6 and -0.9 MPa) and treatments of silver nanoparticles with four concentrations (0, 10, 20 and 30 mg / l).Data were analyzed by SAS statistical software (ver.9). First, the normalization of all the data from different germination traits, including germination percentage, germination speed, root length and stalk length and seedling strain, were evaluated using Kolmogorov-Smirnov test. . Then analysis of variance of data and comparison of means were done using Duncan's test at 5% level. The results showed that the interaction of species, drought stress and nanoparticles on germination rate and shoot length were significant at 5% probability level. The highest germination percentage was observed in both species in control treatment and with increasing dryness, germination percentage, germination rate and seed vigor decreased in both species. Thymus daenensis Celak had a higher rate of germination than the species of Thymus vulgaris L. The species of Thymus vulgaris L in comparison with the species of Thymus daenensis Celak has a relatively low level of roots in terms of the length of its cultivation. On the other hand, silver nanoparticles in non-dry conditions in Thymus vulgaris L.caused an increase in the length of the root, but in the species of Thymus daenensis Celak it was not observed. In general, silver nanoparticles in all traits, with the exception of stem length, had only a mild-to-moderate-particle dose of 30 MPa. Under drought stress conditions, silver nanoparticles in all traits, with the exception of stem length, had only a slight increase of -0.3 MPa, which results in the ability of silver nanoparticles to reduce the negative effects of drought stress below -0.3 MPa, especially Proof of nanoparticles with a concentration of 30 mg / l. Due to the favorable germination and rapid seedling growth, better seeding and reduced competition with other plants, the use of nanoparticles in these two important species of thyme can be a good way to produce these two species in drought conditions. In the life span of the plant, rarely favorable conditions are provided in terms of different environmental characteristics, and as a result, the actual germination in the field is less than the predicted value in germination tests. Therefore, seed vigor index can be more effective in determining the seed germination rate in the field. However, increasing the index of seed vigor with the presence of silver nanoparticles at low levels of dryness has been proved in these two species, but to check other characteristics of the above plants, we need additional testing in field conditions.

Harvesting time is one of the most important factors affecting the seed quality. In order to determine the effects of harvesting time on quantity and quality of plantago major seeds, two experiments were carried out in the Ferdowsi University of Mashhad in 2014. In the first experiment six plantain ecotypes (Birjand, Ghaen, Torbat Hydarieh, Mashhad, Kalat and Bojnord) grown in the field and plant spikes were harvested in six stages with 15 days interval (15, 30, 45, 60, 75 and 90 days after 50% pollination), then germination of harvested seed was tested in the laboratory. Number of spike per plant and its length after 50% of pollination increased and reached to the maximum in 75 and 60 days after that, respectively. Kalat ecotype had the fewest and the shortest spikes, while Birjand and Bojnoord ecotypes produced the longest spikes. The maximum seed weight per spike for Kalat and Bojnoord ecotypes was obtained at 90 days after 50% pollination, while in the other ecotypes it was observed at 75 days after that. The highest germination, speed germination length and weight vigor index in Ghaen ecotype was observed at 75 days after 50% pollination, while in the Torbat Hydarieh ecotype they were observed at 45 days after 50% pollination. In Ghaen, Torbat Hydarieh and Mashhad ecotypes delaying in harvest time of 75 days after 50% pollination causes seed losses and reduction in seed germination.

In order to effect primary germination percent of seed lot and seed size and shape hybrid maize (Zea mays L.,) single cross 704 (Sc. 704) on seed vigor was carried out in seed quality analysis laboratory and research field as factorial experiment by completely randomized design and randomized complete block design respectively with four replications at Seed and Plant Certification and Registration Institute (SPCRI) in 2012. The treatments were included at three seed size and shape flat, medium and round by seed primary germination percent 88, 90 and 92%. The seed and seedling vigor were studied at the laboratory by seedling growth analysis through standard germination test and normal seedlings percent, mean daily germination, coefficient of velocity of germination, seedling length and dry weight and seedling length and weight vigor indices determined in laboratory. Also seedling field emergence percent and rate and seedling length and weight vigor indices in field measured. The results showed that seeds having various primary germination percent had significant different related to seed and seedling vigor indices. Also flat seed shape compared with round shape and medium size seeds had higher germination ability and related to seed and seedling vigor indices. In spite of this results, studied related to seedling emergence and vigor if field indices of having various primary germination percent and size and shape seeds had not significant difference but mean daily germination with seedling emergence percent and rate in field had significant positive correlation. Generally, under this experiment conditions seeds having higher primary germination percent and flat shape had seeds had more germination ability and stronger vigor.

In order to assess seed deterioration of soybean at Ardebil province this study was conducted as a factorial experiment based on randomized complete block design in 2014. The treatments were consisted of germination ability, seed moisture content and seed storing conditions. Germination ability treatment was concluded of three germination levels: 80%, 85% and 90%. Also three rates of seed moisture content including 10%, 12% and 14%; and two seed storing conditions including seed storage of Moghan and controlled storage were considered as second and third treatments. The results indicated that seed quality significantly reduced by increasing the seed moisture content up to 14% and this moisture content was determined as inappropriate moisture for soybean seed storage. Seeds with high moisture content showed significantly lower normal seedlings percent, germination rate and seedling vigor indices. However, there was no significant difference between 12% and 10% seed moisture contents, so it can be concluded that 12% seed moisture content is proper moisture for soybean seed storage. According to the results, enhancement of seed moisture content more than 12% will result in more accelerated deterioration of soybean seed, in a way that seeds with higher moisture content, especially at inappropriate seed storage conditions will lose their quality and will cause yield reduction at field due to low plant density aroused from inadequate seedling emergence.

In order to study the effect of foliar application of zinc and iron on germination of soybaen seed under different level of irrigation, an experiment was conducted in 2009 at Shahrekord agricultural research center. Main factor was including of four levels of drought stress as irrigation (irrigation after 60, 80, 100 and 120 mm evaporation from class A evaporation basin) and sub factor was including of four levels of foliar applications (water, zinc sulfate, iron sulfate and combined of zinc and iron sulfate). Results showed that seed yield, seed zinc content, germination percent and rate and mean germination time and seedling and cotyledon dry weight were affected by the interaction of irrigation and foliar application. Irrigation after more eveporation significantly decreased 1000-seed weight. Foliar application of ironand combined of zinc and iron had significant effect on seed iron content. Germination percent in irrigation after 80 and 120 mm evaporation from the class A evaporation basin was not affected by foliar application, and iron foliar application in other levels of irrigation, let to the lowest germination percent. Foliar application of iron had the highest mean germination time. Foliar application of element. Root and shoot dry weight was increased by foliar application of zinc compared to water and combined of zinc and iron foliar application. Generally foliar application of zinc and combined zinc and iron, could improve most of the germination characteristics. High correlation coeficient between 1000-seed wieght and seed zinc content with most of the germination characteristics, showed that these traits had maximum effect on germination of soybean.