• Journal of Korean Society of Forest Science
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• v.31 no.1
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• pp.48-52
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• 1976

In order to investigate the effects of seed weight, size (length and thickness), and maturation period (early maturing seed or late maturing seed) on growth of first-year seedlings in Pinus koraiensis, pot cultivation experiment with seeds collected from Gangweon University Forest was carried out under relatively controlled environment condition. At the end of one growing season, not only fresh weight, length, diameter (at underside of cotyledon) and root length of seedlings, but also number and length of cotyledon were measured. Results are as follows; 1. Germination percentage is independent of weight and size of seeds, but it was influenced by maturation period, that is, late maturing seeds surpass early maturing one in germination percentage. 2. Germination percentage is affected by maturation period of seeds in 18.3% of contribution rate. 3. Each growth of first-year seedlings is influenced considerably by the differences of weight, length and thickness of seeds, that is, heavy and large seeds produce larger seedlings than do light and small seeds. Particularly, fresh weight, diameter, length of cotyledon are significantly affected by differences of seed weight and size (length and thickness) in 50-90% of contribution rate. 4. Differences of seed weight and thickness have a tendency to affect more on growth of first-year seedlings than do differences of seed length. 5. Seedlings from late maturing seeds are superior than those from early maturing one in fresh weight, diameter of seedlings and length of cotyledon, but it's influence is a little.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.1
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• pp.66-71
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• 1980

Sesame cultivar Suweon 9 was sown at two planting time, June 19 and July 3, to study flowering and seed maturation process. Flowering began at 37-40 days after sowing at the 2-4th node and proceeded to upper node with the speed of 1.78 days (June 19 planting) and 1.56 days (July 3 planting) per node until Sept. 1. Sesame capsule reached its full size about 10 days after flowering. Number of sesame seed increased until 15 days, but seed weight gain occurred from 10 days to 35 days after flowering, that meant 25 days the actual seed filling period. The capsule flowered later than Aug. 14 remained immature. There was no more seed weight gain when average. temperature dropped below $20^{\circ}C$ (around Sept.15) and 50% of leaves had senesced. Discussion includes that sesame as an 8determinate plant may have independent source-sink relationship at each node.

• Korean Journal of Medicinal Crop Science
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• v.23 no.1
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• pp.8-12
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• 2015

Characteristic of seed for Sageretia thea fruits collected from the habitat of harvest season in Jeju and their germination ratio in different temperatures were considered. The average weight was 0.2 g, average diameter was 7.2 mm, average length was 6.5 mm, and size distribution range was 5.1 ~ 10.0 mm. The number of seeds per fruit was 1.8, and 1000 grain weight was 7.77 g with diameter of 3.7 mm and thickness of 1.7 mm in size. The fruit maturation was investigated to be from April 27 to June 1, when the best maturation period was about a week, May 11 to May 18. Also, the fruits grown on May 4 to May 11 were seen to have the bigger in transverse size and weight with a tendency of the earlier maturation date has the greater the number of seeds. S. thea seeds pretreated for 24 hours at $50^{\circ}C$ were not germinated, while most of those pretreated for 24 hours at $4^{\circ}C$ were successfully germinated at any degree of temperature (except at a temperature of $10^{\circ}C$). Particularly, the highest germination rate of 55% was made at $15^{\circ}C$, and plumule and radicle were best grown within the temperature range of $25^{\circ}C$.

• The Korean Journal of Ecology
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• v.19 no.2
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• pp.107-123
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• 1996

The position effects on the abortion of flowers, fruits, and ovules were examined in relation to the resource limitation hypothesis using a temperate legume species, Vicia cracca. Fifty plants were randomly sampled from a natural population located at the Belmont Conservation Site in Belmont, MA, USA. Due to indeterminant growth and acropetal flowering of this species, the position of flower or fruit on the plant was able to be coded by the combination of architectural levels such as plant half (lower and upper half) and inflorescence half (lower and upper half) within each plant half. Overall, only 17.3% of the flowers on an inflorescence began to develop into fruits, while overall 36.0% of the fruits initiated failed to mature. Consequently, 11.5% of the flowers successfully matured into fruits. The mean flower number per inflorescence differed significantly among plants as well as between plant halves. Although the probability of fruit initiation was higher in the lower halves of both plant and inflorescence than in the upper halves of the latter, fruit abortion rate differed significantly only between plant halves. The overall mean seed set was 33.6%, implying that about two out of six ovules in a fruit matured into seeds. The seed set was independent of both plant identity and architectural level unlike other reproductive characters examined. When the ovule developmental stage was examined on data pooled over all fruits, the proportion of ovules in varying developmental stages decreased in order of early abortion, seed maturation, late abortion, and seed predation (48.4, 34.9, 12.2, and 4.5%, respectively). A within-fruit ovule position was also used as a class variable for the analysis of position effects on ovule development. All architectural levels considered exerted singificant influence over the ovule development. In particular, ovule development was strongly affected by the within-fruit ovule position. Ovules in both extreme ends within a fruit tended to abort early, while those in the middle position were more likely to mature into seeds. The strong position effects detected from the flowering to seed maturation stage were interpreted as an indication of competitive interaction among reproductive characters which are largely constrained by plant architecture.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.3
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• pp.231-238
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• 2010

The Induction of regeneration and maturation in the free-living gametophytes of Ecklonia stolonifera Okamura was studied at four temperatures (5, 10, 15, and $20^{\circ}C$), four levels of irradiance (5, 10, 20, and 40 ${\mu}mol\;m^{-2}s^{-1}$) and three photoperiods (14:10, 12:12, and 10:14 h L:D). Female gametophyte fragments were maintained in active regeneration without reaching sexual maturity under $5{\sim}10^{\circ}C$, 10 ${\mu}mol\;m^{-2}s^{-1}$, 10:14 h (L:D), whereas the conditions for male gametophytes were slightly different at $20^{\circ}C$, 40 ${\mu}mol\;m^{-2}s^{-1}$, 10:14 h (L:D). The sexual maturation of female and male gametophytes was facilitated at $15^{\circ}C$, 20 ${\mu}mol\;m^{-2}s^{-1}$, 14:10 h (L:D). These results provide basic information for controlling the regeneration and maturation of the free-living gametophytes for artificial seed production of E. stolonifera.

• Journal of Forest and Environmental Science
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• v.38 no.4
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• pp.256-262
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• 2022

The timing of seed harvesting is an important decision in the management of seed orchards because it affects seed quality and yield. To investigate the effect of cone harvest time on seed quality and determine the optimal harvesting time, cones were regularly collected in seven times and germination tests were performed at each harvest time in two clonal seed orchards of Chamaecyparis obtusa. As cones developed, the percentage of seed germination increased before cone moisture content began to decrease significantly. The moisture contents of cones were highest at the first collection as 68.3% and 67.3% in Jeju and Gochang seed orchards respectively. At this time, germination speed was slowest, indicating poor seed vigour. The highest germination was found at the second stage in Jeju (36.5%) and at the seventh stage in Gochang (28.6%) seed orchard. The germination speed increased as cone moisture content decreased. Additionally, changes of seed vigour differed among the developmental stages in both seed orchards. Consequently, the optimal cone harvest time of C. obtusa seed orchards in Jeju was early September when high germination percentage was obtained. In Gochang seed orchards, late October was optimal cone harvest time when the germination speed was fast and the cone moisture content decreased.

• Journal of Korean Society of Forest Science
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• v.97 no.2
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• pp.135-139
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• 2008

Seed production and germination could be influenced by some factors. The picking time and climate factors are regarded as the elements to obtain sound seeds. We have observed the seed productivity and germination of seeds from trees of Chamaecyparis obtusa selected in a clonal seed orchard. Depending on picking time, various shapes from liquid material, something jellied to the fully matured one were observed. Germination aspects varied throughout the test days. After 20days of seeding in a glass petri-dish, germinal apparatuses appeared from the all seeds which had been picked from after at the end of August. The highest germination rate of about 30% was observed from the seeds picked from $20^{th}$ of September and $10^{th}$ of October. Seed production was about two times higher in 2005 than in 2006 and the average germination rate was also higher in 2005. We have also analyzed the effects of climatic factors about two consecutive years on seed productivity. Among the climatic factors, monthly sum of temperature and of precipitation were the main factors for maturation of Chamaecyparis obtusa seeds.

• Proceedings of the Zoological Society Korea Conference
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• 1999.10b
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• pp.167.2-167
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• 1999

No Abstract, See Full Text

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.3
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• pp.225-228
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• 1989

Under the different conditions of planting density, maturation dates, stem length, oil contents, stem yield and seed yield of flax were investigated in 1984. The results were as followed: Wiera and Storment Goss were earlier in the maturation dates with increasing plant density, However Taijungsung #1 was delayed. Though there is a difference between the varieties stem length was getting longer with increasing plant density., Oil contents were getting higher with increasing plant density, stem yield and seed yield were increased with increasing plant density, on the contrary those were decreased by the growth of ciliary flax in the case of 1200 plants per 1.2m$^2$. Therefore optimum planting density of flax culture was 12cm x 6cm.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.3
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• pp.147-151
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• 1998

The conductivity test is a measure of electrolytes leakage from plant tissue. The shorter the maturation period after heading was the greater electrical conductivity (EC) of rice seed. The polymer-coated seed was not different in EC compared with non-coated seed. As soaking time of rice seed increased, EC increased gradually. The EC varied from 9.9 to 20.7$\mu$S $cm^{-1}g^{-l}$ for control plots and from 21.3 to 41.7$\mu$S $cm^{-1}g^{-l}$ for heat-killed seeds which were produced by autoclaving seeds at 121$^{\circ}C$ for 20 minutes. The germination speed (the rate of 5th day) of rice seed was 94% at control plot, 83% at low temperature and 20% at high temperature. Besides, germination percentage was 95% for the control, 92% for the low temperature treatment and 39% for the high temperature treatment. The EC was negatively correlated (r=-0.771$^{**}$) with germination percentage at low temperature. Water uptake in seeds of 30, 40, 50 days after heading (DAH) was greater than that of 20 DAH. Plant height of seedlings was 9.84 cm for the control but 4.32 cm for the high temperature treatment, and the tallest for polymer-coated seed. Dry weight of seedlings was 0.841 g for the control and 0.287 g at high temperature. Besides, the polymer-coated seed was heavier than non-coated seed. The number of roots was largest from 40 to 50 DAH and polymer-coated seed, but was decreased from 20 to 30 DAH. The length of roots was 20.52 cm at control plot and 19.89 cm polymer-coated seed but 8.68 cm for the low temperature treatment and 7.28 cm for the high temperature treatment.