نشریه تحقیقات بذر
پیاپی 42 (بهار 1401)

Germination and seedling establishment are critical and important stages in the life cycle of plants. Therefore, the study of germination and methods of breaking on seed dormancy in plants is of great importance. One of the corrective operations on improving the seed yield of rangeland plants is seed priming. Priming is an operation on the seed that causes the seed to absorb a sufficient amount of water to accelerate the germination process. Trifolium resupinatum is a clover. In this study, in order to germinate seeds from treatments of 100, 200 and 300 mM sodium chloride in 24, 48 and 72 hours, gibberellic acid 125 and 250 ppm during 12, 24 and 48 hours and 0.01 solution, 0.02 and 0.03% of potassium nitrate were used for 12 and 24 hours, respectively. Distilled water was also considered as a control treatment. The study was conducted in a randomized statistical design with 3 replications and two-way analysis of variance was used to analyze the data. Traits such as germination percentage, germination rate, germination index, shoot length, root length, number of germinated seeds, seedling length and seed vigor index were evaluated. The results showed that in the seed germination of Iranian clover species, three chemical treatments had better results in terms of yield of the germination process of the species than other treatments and were recommended as the most desirable pretreatments and potassium nitrate and then acid treatments. Gibberellins had the greatest effect on the seed Dormancy breaking.

Seed germination is an important stage in the life cycle of plants. Seed germination is affected by various environmental stresses such as salinity, high temperature and drought. Squill (Drimia maritima) is a medicinal plant that is used in traditional medicine and the use of seeds is one of the methods of propagation of this plant. There is no information about the effect of environmental stresses on seed germination of this plant. In this study, the effect of temperature treatments (15, 20 and 25 °C) and different salinity levels (0, 50, 100, 150, 200 and 250 mM) on seed germination and seedling growth indices were investigated. The results showed that temperature and salinity treatments have a significant effect on germination and seedling growth indices. At all three temperatures of 15, 20 and 25 °C, seed germination and seedling growth indices decreased under salinity stress and the lowest seed germination and seedling growth were obtained in 200 and 250 mM sodium chloride treatments. At all three temperatures, salinity stress had a inhibitory effect on seedling growth indices such as the length of different seedling sections and the fresh and dry weight of seedlings as well as the seedling vigor index of Squill. The results of the present experiment showed that Squill is sensitive to salinity in the germination stage and the temperature of 20°C is the appropriate temperature for the germination of the Squill’s seed.

In order to investigate the effect of hydropriming and osmopriming on emergence parameters and its interaction with interruption of irrigation at the flowering stage of lentil, experiments were performed in a factorial from completely randomized design with seven concentrations of KNO3, ZnSO4 and pure water was conducted as split plot in randomized complete block design with three replications at farm experiment, in 2017. The main irrigation factor included complete irrigation and interruption of irrigation at flowering stage and the secondary factor included seed priming with potassium nitrate solution and zinc sulfate was each with concentrations of 0.2. and 0.3 percentage distilled water for six hours and control. Seed Priming with potassium nitrate decreased 9.91 and 7.89 percentage mean germination related to control and hydropriming. Coefficient unique emergence increased compared to non-priming with priming levels.

In order to evaluate of effect the precursors of insect pesticides at different temperatures in laboratory on germination characteristics and seedling growth of downy and de linter seeds of two cotton cultivars, this research was conducted in as a factorial experiment with four-factor in the form of completely randomized design (CRD) with four replications in Seed technology laboratory of Kashmar University Jihad Institute in Kashmar in 2019-2020. In factorial experiment, the first factor includes two types of seeds (downy and de linterseeds) and the second factor is the type of cultivar (Varamin and Khorshid cultivar), the third factor is temperature at four levels (18, 20, 22 and 24 oC) and the factor Fourth, insecticide application at three levels (control, Gaucho and Cruz). The results also showed the simple effect of cultivar, temperature, insecticide and also the interaction of seed and cultivar type, effect of seed and temperature type, effect of seed and insecticide type, effect of cultivar and insecticide, effect of temperature and effects of combined cultivar, seed type and insecticide on percentage of germination and simple effect of cultivar, temperature, insecticide and also the interaction of seed and cultivar type, effect of seed and temperature type, effect of seed and insecticide type, effect of cultivar and insecticide, effects of combined cultivar, seed type and insecticide on seedling length at the probability level of 1% were significant. The results of the average comparison showed that the highest seedling length (74/16 cm) was related to de-linter seeds of Varamin cultivar with Gaucho application and lowest the seedling length (12.44 cm) was related to de-linter seeds of Khorshid cultivar with out insecticide application. The results showed that the highest percentage of germination (93.98%) was related to de-linter seeds of Khorshid cultivar and also downy seeds with Gaucho (93.43) application. Generally, in order to produce seeds with a high germination percentage, Khorshid seeds and application of Gaucho and to increase SV II index Varamin cultivar in the first crop with application of Gaucho was recommended.

In order to evaluate the effect of seed priming of Quinoa (Chenopodium quinoa Willd) on Seedling growth and germination Indexes of two varieties of Quinoa (Titicaca-Giza 1), studies in the form of a factorial experiment in a randomized complete block design (RCBD) with two factors four repetitions were conducted of Seed Technology Laboratory Shahed University in 2020. The experiment was the first factor included control ((no priming), Hydropriming, Potassium nitrate (0.02% w / v), Salicylic acid (0.6 mM), Calcium chloride (at 20 and 40 mM) and two genotypes of quinoa (TiticacaGiza 1). The best priming level for 40 mM calcium chloride was in both genotypes. Results of experiment showed that effect of priming on seed percentage at the level of one percent was significant but their interaction priming, genotyping on seed percentage not significant. Also, effect of priming, genotyping and their interaction on normal seedling percentage, seedling length, allometric coefficient and seed vigor length index, at the level of one percent was significant. Results showed that the highest seed percentage obtained in for level 20 (100 %) and 40 (100 %) mM calcium chloride priming in both genotypes (Titicaca-Giza 1). Generally, priming of 40 mM calcium chloride to highest germination indexes and of Titicaca and Giza1 genotype was recommended.

Natural biostimulants such as seaweed and humic acid may have positive effects on germination. Seaweed extract comprises high and low consumption elements, amino acids, plant growth regulators, and vitamins which increase root absorption and improve the quality and compounds of antioxidants. Humic acid is a mixture of sources such as soil, humus, oxidized lignite, coal and etc. Nutrients are essential for the growth and development of plants which are consumed in lower amounts. This current study was conducted to investigate the effects of biostimulants of seaweed and humic acid and some nutrients on seeding and other related traits in soybean. The current study showed that biostimulants of seaweed extract and humic acid and some nutrients had positive effects on germination.