نشریه علوم و فناوری بذر ایران
سال یازدهم شماره 3 (پیاپی 27، پاییز 1401)

In spite of optimal qualitative traits of sweet corn plant, its cultivation is limited due to some problems in germination, poor vigor, seed wrinkling and seedling weak establishment in the soil, using mineral compounds in seed coating could improve germination and seedling growth indices, and physical characteristics of sweet corn seeds. In order to improve efficacy of sweet corn seed using seed coating, this experiment was conducted based on three-factor factorial in a completely randomized design with four replications of 25 seeds at the laboratory at the Department of Agronomy and Plant Breeding, Yasouj University, Iran, in 2018. The first factor included the concentrations of chitosan solutions (zero- 0.3% acetic acid, 0.5 and 0.75%), the second factor was gum arabic (zero- distilled water and 0.4%) and the third factor was V10K2.5P5 coating composition (10, 2.5 and 5 fold to seed weight respectively in Vermiculite (V), kaolin (K) and perlite (P)) and no coating treatment. The interaction effect showed that that the highest seedling length vigor index (183.24) was related to the coating treatment of gum arabic 0.4% and coating composition of V10K2.5P5 that had a significant difference with a treatment that had the lowest seedling length vigor index (85.70) from the coating treatment gum arabic 0.4% and no coating composition. The overall results showed that the coating treatment of chitosan 0.5% + coating composition of V10K2.5P5 + gum arabic 0.4% was more effective treatment on germination indices and seedling and physical characteristics of sweet corn seeds compared to other treatments.

To investigate the effect of the maternal plant's growth environment on qualitative characteristics and germination of borage seeds after storage, an experiment was carried out in a randomized complete block design with three replications at the University of Mohaghegh Ardabili. The treatments included seeds resulting from maternal plants sprayed with humic acid (0.5 g L-1), chitosan (1 g L-1), and the combination of humic acid and chitosan (0.5 g L-1 + 1 g L-1), salicylic acid. (4 mM), ascorbic acid (0.85 mM), potassium nitrate (20 mM) and control.The results showed that under non-storage conditions, the seeds that resulted from the maternal plants treated with bio-stimulants and growth regulators exhibited higher seed germination and seedling growth than those from the control plants. In this condition, foliar application of the maternal plants with humic acid+chitosan had the highest effect on the seed germination and seedling growth characteristics by increasing the germination percentage and rate, vigor index, seedlings dry weight and length. Although five years of dry seed storage reduced the seed viability and vigor, foliar application of maternal plants reduced the negative effects of storage on germination and enhanced the seed germination percentage and seedlings length, and dry weight by increasing the seed viability and seed vigor index. In general, among the foliar spraying treatments of the maternal plants, the combined foliar application of humic acid+chitosan, maybe due to the synergistic effects, can be considered the best treatment to improve the borage seed longevity, germination characteristics, and seedling growth.

In order to investigate the effect of cold plasma on seed germination characteristics and seedling growth of soybean commercial cultivars, an experiment in the form of a nest-factorial design with four replications was performed at the Plasma Physics Research Center of Islamic Azad University, Tehran Research Sciences Branch and Seed and Plant Certification and Registration Institute (SPCRI) in 2021. Seeds were exposed to cold plasma for 30, 60, 180, 300 and 420 seconds. In general, germination percentage from 0 to 66.97%, germination rate from 0 to 32.17%, germination index from 3.61 to 60.09%, mean germination time from 4.62 to 66.66%, root length 2.87 to 56.13%, seedling length 2.70 to 78.13%, normal seedling number 0 to 30.26% and seedling dry weight 1.36 to 36.63% increased compared to control treatment. The results of our study showed that 60 seconds treatment had the most positive effect on seed germination characteristics and seedling growth of soybean.

In order to evaluate the effect of temperature, drought and priming on the percentage and rate germination of corn seeds, a factorial experiment based on a completely randomized design with four replicates was conducted. Treatments included eight temperature (5, 10, 15, 20, 25, 30, 35, 40 and 45 ºC), four drought potential (0, -0.4, -0.8 and -1.2 MPa), and five priming (control, hydroprimin, GA priming, ABA priming and, SA ptiming). Both percentage and rate of germination were inhibited at osmotic potentials ≤−0.8 MPa PEG. At 35 ºC temperature. Germination percentage of unprimed seeds was reduced from 94 to 36% in −1.2 MPa. Under these conditions, gibberellic acid hormone treatment improved seed germination. The effect of temperature on germination can be defined in terms of cardinal temperatures. We compared three non-linear regression models (Dent-like, segmented and beta). The outcome revealed that the Dent-like function was suitable for use in describing seed germination response to temperature. The base, optimum 1, optimum 2 and ceiling temperature were estimated to be 9.51, 24.12, 35 and 44.62 °C, respectively. The response of germination rate to both temperature and water potential can be described as a non-linear function of the hydrothermal model. According to the results of this study, hydropriming, gibberellic acid, and salicylic acid increased the mean deviation of the base temperature compared to non-priming treatment, increasing the standard deviation of the base temperature indicates the ability of seed germination in different osmotic potentials.

In this experiment, physical and chemical characteristics of sugar beet seed and its relationship with germination traits was studied. This traits were evaluated on 10 sugar beet singles crosses that obtained from three locations including Ardabil, Firuzkuh, and Karaj. Results showed that bulk density, true density and electrical conductivity are influenced by environment and genotype. Percentage of solids soluble in sugar beet pericarp (germination inhibitors) it was only affected by the seed production environment. Both genetics and environmental conditions on the maternal plant during seed development and maturing were effective on germination percentage, germination velocity and mean germination time. But the germination uniformity of sugar beet seeds was only affected by genotype. On the other, the correlation between bulk density, true density, electrical conductivity, porosity and percentage of solids in pericarp solution of sugar beet seeds with some germination traits was significant. But, the germination uniformity had no correlation with the physical and chemical properties of seed. Increased density of the seed pericarp caused decrease of seed quality factors including electrical conductivity and percentage of solids solution on pericarp. Therefore, germination uniformity, which is less affected by the environment, can be used in breeding programs as indicator of seed quality selection. Physical and chemical traits that was a significant correlation with germination traits, in the management of sugar beet seed production with the aim of increasing the extraction coefficient and quality of sugar beet seeds are recommended.

Research on the effect of salinity and drought stress on germination and growth pattern among pasture grass populations is very important to determine the potential of suitable species for restoration and protection as well as fodder production. For this purpose, a research was carried out to evaluate the salinity and drought stress of the Pennisetum divisum plant in the germination and seedling growth stage of 2019 in the seed laboratory of the Faculty of Agriculture of Tehran-Karaj University in the form of a completely randomized design and in 3 replications. The treatments of this experiment included 4 levels of salinity (100-150-200 and 300 mM sodium chloride), 4 levels of dryness (2-, 4-, 6- and 8-bar polyethylene glycol) and distilled water (control). The evaluated traits included germination percentage, germination speed, stem length and root length. The results showed that the germination percentage, germination speed, root length and shoot length increased with the increase of salinity stress up to 200 mM and then decreased so that practically no seeds germinated. In drought stress, the studied traits increased up to -6 times and then started to decrease. The results showed that the Pennisetum divisum plant is relatively resistant to salt and drought stress.