• The Plant Pathology Journal
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• v.35 no.4
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• pp.301-312
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• 2019

Sorghum is the fifth most important cereal worldwide, spreading from Africa throughout the world. It is particularly important in the semi-arid tropics due to its drought tolerance, and when cultivated in Southeast Asia commonly occurs as a second crop during the dry season. We recovered Fusarium from sorghum in Thailand and found F. proliferatum, F. thapsinum and F. verticillioides most frequently, and intermittent isolates of F. sacchari and F. beomiforme. The relatively high frequencies of F. proliferatum and F. verticillioides, suggest mycotoxin contamination, particularly fumonisins and moniliformin, should be evaluated. Genetic variation within the three commonly recovered species was characterized with vegetative compatibility, mating type, Amplified Fragment Length Polymorphisms (AFLPs), and female fertility. Effective population number ($N_e$) was highest for F. verticillioides and lowest for F. thapsinum with values based on mating type allele frequencies higher than those based on female fertility. Based on AFLP genetic variation, the F. thapsinum populations were the most closely related, the F. verticillioides populations were the most distantly related, and the F. proliferatum populations were in an intermediate position. The genetic variation observed could result if F. thapsinum is introduced primarily with seed, while F. proliferatum and F. verticillioides could arrive with seed or be carried over from previous crops, e.g., rice or maize, which sorghum is following. Confirmation of species transmission patterns is needed to understand the agricultural systems in which sorghum is grown in Southeast Asia, which are quite different from the systems found in Africa, Australia, India and the Americas.

• The Southeast Asian review
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• v.20 no.3
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• pp.147-182
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• 2010

The purpose of this study is to examine the population changes in the nine Southeast Asian countries, including Cambodia, Lao People's Democratic Republic, Philippine, Indonesia, Malaysia, Myanmar, Singapore, Vietnam, and Thailand. According to the demographic transition theory which described the transition from high birth and death rates to low birth and death rates, the demographic changes in less developed countries, including the Southeast Asian countries, follow the general pattern of the population changes that the Western countries had experienced. However, this theory does not consider the fact that the demographic behaviors such as fertility and mortality tend to be ethnocentric (or particular). Therefore, I examine in this paper both the generality and particularity of the population changes in the Southeast Asia . The analytic results are consistent with my assumptions. Every country in the Southeast Asia will soon reach the third phrase of the demographic transition and meet population ageing process. However, the timings arriving at the third phrase can differ. Singapore which is the most developed country had firstly passed through the demographic transition and the highest level of population ageing. Cambodia and Lao People's Democratic Republic, the least developed countries, will lastly arrive at the third phrase and the ageing society. In addition, among the three countries which had experienced war or civil war, only Cambodia had experienced babyboom.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.2
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• pp.129-136
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• 2009

The incidence of ectopic pregnancy is increased since in vitro fertilization-embryo transfer (IVF-ET) has started. And because of the possibility of combined pregnancy after IVF-ET, bilateral adnexal area and other portion of pelvis should be examined carefully by transvaginal ultrasonography during follow-up period. The rate of combined pregnancy after IVF is estimated to be as high as 0.2~1%. Since the incidence of combined pregnancies is markedly higher with IVF, special attention to this possibility after ET is warranted. According to a recent report, the occurrence of interstitial pregnancy is estimated to be 1:3600 for all pregnancies achieved with IVF. The prevalence of interstitial pregnancies is 2~4% of ectopic pregnancies. Interstitial pregnancies tend to be diagnosed later than most other ectopic pregnancies, and if uterine rupture occurs, the resulting hemorrhage can be severe. Currently, about 2% to 3% of interstitial pregnancies are thought to carry a maternal death, which is twice that of other tubal gestations. We report a case of simultaneous left tubal and right interstitial pregnancies after IVF-ET with a brief review of literature.

• Korea journal of population studies
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• v.30 no.3
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• pp.179-205
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• 2007

Demography has grown as an independent academic discipline in Korea during past 30 years by describing and examining changes of population components such as fertility, mortality, migration, and census, and the "Population Association of Korea" stands on the midst of the growth. High fertility of the 1960s and 70s, which was considered as a hurdle of economic growth, particularly boosted the prosper of demography in Korea by inviting a number of non-demographers as well as demographers to population-related research projects. However, as fertility gradually decreases and becomes no-threat anymore beginning the early 1990s, social interests in demography has withered to lose its academic soils in Korea. A recent phenomenon of the lowest low fertility has revived social need and interest in demography. Unfortunately, once curtailed capacity of Korean demography is not sufficient enough to provide academic and/or practical resources now. This research is conducted to cerebrate the 30th anniversary of "Population Association of Korea" and to seek ways to cultivate academic soils again and to rebuild the capacity of demography in Korea. To do this, this research examines the causes of current struggles of Korean demography by comparing its academic environments with that of America, and offers suggestions for its brighter future.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.4
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• pp.73-80
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• 1980

To facilitate the heterosis breeding which utilizes cytoplasmic-genetic male sterile lines in rape (Brassica napus L.), 511 improved domestic lines were tested for their fertility restoration, maintaining ability and heterosis expression in agronomic characters. About 81 % of 511 lines showed complete fertility restoration and 11 lines could be used as maintainer of male sterility. All yield components except pod length showed greater heterotic effects than that of midparent in $F_1$. These heterotic effects resulted in extraordinary yielding ability as high as 5.6 T/ha in several $F_1$`s.

• Journal of Plant Biology
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• v.14 no.1
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• pp.33-35
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• 1971

After topping, axillary buds of haploid plants derived from cultured anthers were treated with 0.4% aqueous solution of colchicine. Due to the high temperature and dry air at the time of treatment, most of the buds perished. A few months after the colchicine application, however, several shoots arose from the places where the dead buds were originally located. These shoots were mostly diploid. Induction of adventive shoots from the colchicine-treatedaxils was supposed to be rather effective method of obtaining diploid shoots from haploid plants. The diploid plants had larger floral organs than the haploid plants, and had good pollen fertility and seed setting. 24 bivalent chromosomes were observed at MI of the PMC's.

• Journal of Animal Reproduction and Biotechnology
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• v.35 no.2
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• pp.190-197
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• 2020

The effects of the number of frozen-thawed ram sperm per single and double intra-cervical artificial insemination (AI) on fertility in ewes were studied. A total of 89 non-pregnant ewes were synchronized for oestrus with two doses of 100 ㎍ PGF_2α (Cloprostenol) 9 days apart. The ewes were randomly assigned to one of four groups; D200 (n = 23; double AI with 200 × 10⁶ sperm), S200 (n = 24; single AI with 200 × 10⁶ sperm), D100 (n = 24; double AI with 100 × 10⁶ sperm) and S100 (n = 18; single AI with 100 × 10⁶ sperm). Ewes were inseminated within 12 to 18 h for single AI and, within 10 to 12 h and 16 to 18 h for double AI after the onset of oestrus. The onset of oestrus ranged from 28 to 76 h (54.33 ± 1.28 h). The high percentage (29.2%) of ewes showed oestrus between 51 to 60 h. The non-return rates were highest in group D200 (56.5%) and differed significantly (p < 0.05) from group S100 (11.1%). No ewes were pregnant in group S100, and the pregnancy rates among the remaining groups did not differ. The mean gestation period was 152.8 ± 0.5 days and no difference was observed among the groups. The lambing and multiple birth rates were 100% in group D200. The single and twin lambing was highest in group D100 (33.3%) and group D200 (83.3%), respectively. Only one triplet lambing and the highest lambing size (2.2 ± 0.2) was recorded in group D200. In conclusion, double AI with 200 × 10⁶ sperm showed comparatively most practical for achieving high pregnancy rates and lambing performances in Bangladeshi ewes under field conditions.

• Korean Journal of Ecology and Environment
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• v.36 no.1 s.102
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• pp.57-65
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• 2003

The algal growth potential test (AGPT) bioassay were conducted to assess the water quality and fertility in the Chinyang Reservoir and the lower part of the Nam River from August 2000 to July 2001, The AGPT value of the Chinyang Reservoir ranged from 0 to 23.4 mg dw $1^{-1}$, while 79% of the algae cultivation have not grown. The AGPT value was in proportion to phosphorus concentration of the water, and it was less when chlorophyll-a was high. This value was higher in the middle and lower layers than in the upper layer, and in the inflow part where the water is shallower than in the lacustrine. The AGPT value has increased in the whole reservoir in August${\sim}$September when the water volume is high. In contrast, the AGPT value in the Nam River varied greatly compared to that of the reservoir, and ranged from 0 to 252.0 mg dw $1^{-1}$ and 65% of the algae cultivation have grown. The value was less than 10 mg dw $1^{-1}$ in the upstream, over the point where the treated wastewater discharged. It was 57 mg dw $1^{-1}$ on the average in the downstream, except in March and July when the discharged water influenced greatly, exceeding the hypertrophic condition. The result of AGPT shows the differences in the time and space on the reservoir and the streams. The AGPT value has increased in July${\sim}$September, and in December in the inflow part of the reservoir; in March and August${\sim}$December in the lower part; and in January, May, and November in the streams. AGPT is useful not only in defining the influence of the limiting nutrients on the algal growth, but also in evaluating the nutrients fertility in the inland water.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.1
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• pp.63-69
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• 1986

1. Chemical components of fresh tobacco leaves at topping stages were affected variously by fertilizer application level. The more fertilizers were applicated, the higher nitrogen content of leaves was shown regardless of the soil fertility, but phosphorus content was not affected either by phosphorus rate or soil fertility. Potassium content was higher in the leaves grown in fertile soil than infertile at the same application rate. 2. Maturation of tobacco leaves was delayed by applying high level of nitrogen fertilizer, especially in fertile soil. The excessive accumulation of nitrogen in tobacco leaves at later stage of growth resulted in poor quality index for the high content of nicotine and low content of reducing sugar in cured leaves. 3. Nicotine content of cured leaf was increased significantly as nitrogen content increased, regardless of soil fertility, but reducing sugar content was reduced. Nicotine and reducing sugar content of cured leaf were higher in fertile than in infertile soil. 4. Resulting from the facts that nicotine contents were negatively correlated and reducing sugar contents were positively correlated with grading value (Won/Kg), authors suggested that grading index (Won/Kg) of the Office of Monopoly be based on quality index from chemical components of cured leaves.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.4
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• pp.310-318
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• 1991

This experiment was carried out to obtain the information on the variation of chromosome number in pollen mother cell (PMC) and somatic cell of the progeny from the cross between hexaploid triticale cv. Sinkihomil and five hexaploid wheat varieties. The results were summarized as follows: Number of uni-, bi- and tri-valent in PMC was 11.9, 14.4 and 0.44, respectively, in the F$_1$ between triticale and wheat. Significant positive correlation between the pollen fertility and seed set rate, pollen fertility and bivalent number of PMC, and seed set rate and bivalent number of PMC, and negative correlation between pollen fertility and uni-or tri-valent of PMC in the cross between triticale and wheat were detected. F$_1$ (crossed seed) had 42 chromosomes, F$_2$ and F$_1$/P$_1$ showed high frequency of hyperploid (42-49) and F$_1$/P$_2$ showed high frequency of hypoploid (36- 42), which suggest non-random segregation for somatic chromosome number. in the cross between the triticale and wheat.