• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.4
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• pp.421-426
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• 2008

Freshly harvested seed of Chinese milk vetch (Astragalus sinicus L.; CMV) was strongly dormant because of hardseedness. Seeds of freshly harvested germinated only 8% while clipping the seed coat completely overcome the innate dormancy, which indicates inhibition of germination of the seed is mainly due to seed coat (87%). The dormant (intact) hard seeds did not imbibe water whereas the non-dormant (clipped) seeds took up rapidly. In natural environment condition, the hard seed coat dormancy was broken only after 5 months after seed harvest. To break such a strong seed coat dormancy, the chemical and heat treatments were effective. Concentrated sulfuric acid was more effective than dry heat and hot water treatments. Hot water treatment improved germination but the germination percentage was less than 41%. Treatments increased germination due to its effect on the seed coat integrity. A scanning electron microscope reveled that disruption of seed coat layers and subsequent development of numerous crack in the hilum region of the seed and on the seed coat surface of concentrated sulfuric acid treatment and formation of cracks in the dry heat treatments, respectively, were observed in the seed coat surface, which served as water entry points.

• FLOWER RESEARCH JOURNAL
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• v.16 no.2
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• pp.134-142
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• 2008

This work aims to obtain basic information for seed propagation of Hydrangea serrata for. acuminata. The germination percentage of the seeds taken on 15 November, 30 December, and 23 January was $90.0{\pm}4.16%$, $84.4{\pm}5.52%$, and $88.9{\pm}2.40%$, respectively. This suggest that seeds of Hydrangea serrata for. acuminata are non-dormant seeds. The optimum temperature for germination was $25^{\circ}C$ and light was necessary. Most of the growth parameters (shoot and leaf length, stem diameter, root length, no. of roots, T/R ratio, and fresh and dry wts.) were significantly greater at $25/20^{\circ}C$ and $25^{\circ}C$ than at the other temperatures. Low T/R ratio at relatively cool temperatures (15 and $20^{\circ}C$) was caused by suppressed top growth. In light quality treatment, red light (RL) significantly enhanced stem elongation. The greatest photosynthetic pigments (total chl, chl a/b, and carotenoid) were observed in seedlings grown in blue light (BL), followed by seedlings grown in RL+BL. When blue light was added, higher pigment contents were found. Effect of plug cell size (50, 72, 128, 162 and 200 cells) on the growth of seedlings was investigated. The highest top growth was observed in seedlings grown in 50 cell trays, followed by seedlings grown in 72, 128, 162, and 200 cell trays. However, there was no significant differences between 162 and 200 cell trays. Especially, smaller size leaves were observed in seedlings grown in smaller cell trays (lower volume and high plant density).

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.437-442
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• 2015

Studies to estimate seed longevity and dormancy of creeping bentgrass (Agrostis stolonifera L.) were conducted from 2000 to 2005 at Corvallis and Hermiston, Oregon. Seeds from three transgenic glyphosate resistant creeping bentgrass lines, 48-10, 48-13, and ASR368, and one non-transgenic glyphosate susceptible line, SR1020, were used. Creeping bentgrass seeds were buried at 3, 18 and 31 cm in 2000 and removed 6, 12, 18, 24, and 51 months later. Soil type and climatic conditions were different at the two locations. At Corvallis, the soil was a Malabon silty clay loam, and the winters wet and mild. The soil at Hermiston was an Adkins fine sandy loam, and winters drier and colder. Seeds of all creeping bentgrass lines deteriorated faster at Corvallis than at Hermiston. The estimated half-lives of creeping bentgrass lines buried at Corvallis were 8.4 to 20.2 months, while those buried at Hermiston were 8.4 to 37.7 months. At both sites, seeds of the glyphosate resistant lines, 48-10 and 48-13, deteriorated faster than the susceptible line, SR1020. However, seed deterioration in the resistant line, ASR368, was slower than all other creeping bentgrass lines. Based on the germination test, exhumed intact seeds at Corvallis were more dormant than those at Hermiston. If buried, it could be expected that viable creeping bentgrass seeds will persist more than 4 years after the seeds are introduced to a site, but environmental conditions can influence both seed longevity and dormancy.

• Korean Journal of Plant Resources
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• v.29 no.4
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• pp.385-392
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• 2016

This research was performed to develop seminal propagation method of Saururus chinensis (Lour.) Baill. by conducting a rigorous germination study. Well-selected seeds were dry-stored at 4 ± 1.0℃ during the experiment. To study dormancy type, non-stored seeds were analyzed by embryo observation, germination test and detecting for any difficulties in seed coat to absorb moisture. Then to improve germination, seeds were submerged for 24 hours in a solution of varying concentrations containing one of plant growth regulators and minerals. According to research, fleshly matured seeds had an undifferentiated embryo and had a low germination rate below 5%. In addition, water submersion led to moisture absorption, embryo in the seeds grew and germinated so it was deemed morphophysiological dormant seeds. Percent germination (PG) and germination energy (GE) was greatly improved by soaking in plant growth regulators and minerals for 24 hours. Especially, 500 ㎎/L GA₃ treatment resulted in the highest GE as 46.1%. KNO₃ meaningfully improved PG (54.3∼57.7%) at 10∼20 mM but effect of minerals on germination acceleration as GE were negatively impacted in all concentrations.

• Korean Journal of Weed Science
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• v.30 no.1
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• pp.25-33
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• 2010

Several experiments were conducted in growth chambers and a greenhouse to determine the influence of various environmental factors on seed germination and seedling emergence of Indian jointvetch. Fully matured seeds of Indian jointvetch germinated only 42%. The germination percent increased as the storage temperature increased with time. More than 90% seeds germinated when the seeds were kept at $40^{\circ}C$ for seven months, but germination was 58.9 and 55.1% when kept at 25 and $4^{\circ}C$, respectively. Non-dormant seeds of Indian jointvetch germinated 91.1 and 92.4% at 30 and $30/25^{\circ}C$, respectively. Germination percent increased with increasing both prethermal temperature and time. The prethermal temperature of $90^{\circ}C$ for 40 minutes was the best for maximum germination (94.5%). Germination and growth of Indian jointvetch tended to decrease slightly until -0.3 MPa osmotic potential (water stress induction) and then declined drastically and the seeds did not germinate at below -0.5 MPa osmotic potential. Indian jointvetch seems to grow well in moist and flooding conditions since emergence and growth of seedling increased with increasing soil moisture content and the water level.

• Korean Journal of Environmental Biology
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• v.34 no.2
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• pp.63-72
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• 2016

The objective of this study was to identify the life form characteristics, naturalized degree and introduction period of naturalized plants on upland fields in South Korea. The survey sites were selected in 222 upland fields over 9 provinces where are relatively dry soil conditions and are disturbed continuously by farming practices. It seemed that these uplands maintain good condition for the invasion and settlement of alien plants. Field surveys were carried out twice from May to June and from August to September in 2013. The vascular plants of the upland fields were listed into 539 taxa which contain 103 families, 320 genera, 448 species, 2 subspecies, 74 varieties and 15 forms. Ninety nine taxa were naturalized plants composed of 23 families, 64 genera, 91 species and 8 varieties. The urbanization index and naturalized index is 30.65% and 18.37%, respectively. Among total 99 naturalized plants, Compositae (30 taxa) was the most dominant family, and followed by Gramineae (14 taxa). On the basis of dormancy form, 78 taxa were belong to Th (Therophyte). In radicoid form, $R_5$ plants (86 taxa) and $R_3$ plants (14 taxa) were dominantly distributed. In disseminule form, $D_4$ including 63 taxa and $D_2$ containing 26 taxa were dominant. On the basis of growth form, erect form (e) containing 26 taxa was dominant. In conclusion, life form spectrum was $Th-R_5-D_4-e$ type. According to life form analysis, naturalized degree and introduction period, alien plants with unique characteristics may have high ability to settle and spread nationwide after inflow into South Korea. It needs further to observe some plant species with or without ecological features such as widely disseminated seeds by wind or water, high seed productivity, long life-span seeds, high germination rate of seeds, or non-dormant germinable seed.