• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.2
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• pp.9-16
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• 1979

528 Korean land races of barley were examined for IS agronomic traits to determine if any preferential trait associations with early heading and winter hardiness existed in this collection. Eight traits were non-randomly associated with the 1977～'78 cold damage levels, and seven traits were non-randomly associated with heading date. No early heading, least-cold-damaged land race lines were found. However the least-cold-damaged class preferentially associated with mid-early heading land race lines. Ten traits were preferentially associated with the mid-early heading, least-cold-damaged class. The utilization of these associations should increase the probability that genes for winter hardiness will be preserved in the mid-early heading selections from this collection.

• Proceedings of the Korean Society of Crop Science Conference
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• 1985.05a
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• pp.24.1-24.1
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• 1985

• Proceedings of the Korean Society of Grassland Science Conference
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• 2002.09a
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• pp.36-36
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• 2002

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.3
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• pp.254-260
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• 1984

As a basic study for development of early wheats an experiment was carried out at four sites of Korea by use of 60 varieties. Analysis of variance for heading and maturing dates revealed that there were highly significant among varieties, but not significant among variety x location-interactions, thus indicating the stable response for earliness at all locations of each variety. Grain filling periods of each variety showed the stable response at all locations like those of heading and maturing dates, however, there showed significance among locations for early group, and among varieties for late group. High correlations were between growth habit and winter survival for early varieties, and between shortday length and grain filling period for late one. Interior factors most closely related to heading date were growth habit and winter survival, and winter survival showed highly negative correlation with heading date. It needs to breed the early wheats adaptable for southern and/or northern areas separatively. The earlier heading and maturing dates of wheats were, the shorter internodes of culm are, appearing the outstanding phenomenon in early wheats. Heading date appeared negative correlations with test weight and with number of culm before winter, but showed positive correlation with number of kernels/spike.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.3
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• pp.209-213
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• 1991

Early maturing hybrids(Comet 80, Comet 85 and Linda) and mid-late maturing hybrid (Suwon 19) were grown at Suwon to study the influence of maturity, plant population, and sowing date (45, 55, and 65 days delayed from the recommended sowing date of Suwon 19) on the dry matter yields, percentage ears and TDN yields. Com was planted at the density of 60 x 20, 50 x 20 and 40 x 20 em. Dry matter yields were not significantly different between the early and mid-late maturing hybrids in the delayed sowing time, but significantly higher in 20 x 50cm of planting density in early maturing hybrids. As sowing was delayed to Jun. 22 ear content decreased from 40.3% (early maturing hybrid) to 6.7% (Suwon 19). This resulted in significantly 24.1% higher TDN yield in Comet 85 than in Suwon 19.

• Development and Reproduction
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• v.10 no.4
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• pp.215-225
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• 2006

Precocious puberty is defined as the appearance of secondary sex characteristics before age 8 years in girls (or menarche before age 9 years) and before 9 years in boys. The age of onset of puberty is progressing to younger age. The pubertal activation of gonadotrophin releasing hormone(GnRH) release requires coordinated changes in excitatory or inhibitory amino acids, growth factors, and a group of transcriptional regulators. A number of factors affecting precocious puberty were explored, including the role of genetic factors, nutrition(body fat) and exposure to endocrine disrupting chemicals. In addition to the psychosocial disturbances associated with precocious puberty, the premature pubertal growth spurt and the accelerated bone maturation result in reduced adult height. Precocious puberty may be gonadotrophin-dependent premature activation of the GnRH pulse generator or gonadotrophin-independent. In rapidly progressing central precocious puberty, GnRH agonists appear to increase final height. However more data on the effect and long-term safety of GnRHa are needed.

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.04a
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• pp.76-77
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• 2000

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.4
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• pp.343-349
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• 1988

In order to get informations for breeding early barley cultivars, the thermosensitivity and low temperature growth ability about the breeding materials vernalized were tested at the high '||'&'||'amp; low temperature and field conditions. The temperature coefficient (Q10), ratio and thermosensitivity for plant height were various among cultivars versus temperature treatments. The early cultivars had greater Q10 values and insensitive responses to temperature changes. The Q10 and thermosensitivity for the time of flag leaf unfolding were various among cultivars, but the coefficient of variation in the thermosensitivity was greater, so the character would be more useful for investigating the varietal differences. The Q10 and thermosensitivity for plant height were not significantly correlated with Q10 and thermosensitivity for the time of flag leaf unfolding. The periods from heading to flowering were 2 to 4 days at the high temperature plot, but 1 to 11 days at the low temperature plot, showing much greater variations. In general the cultivars with greater difference of heading time between the high and low temperature plots were Suwon 218, SB 76588, Oweolbori, and Jogangbori, showing the sensitive thermophase and early heading.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.3
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• pp.323-329
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• 1987

Five soybean varieties of two early maturing Karikei73 and SS 79168, and three late maturing Tohoku76, Baegunkong and Jangbaegkong were used and evaluated in the study. Of the varieties examined, Karikei73 was characterized by the delayed leaf senescence. The varieties were planted in the pots of 1/3500 a filled with volcanic ash soil at the experimental fields of the National Institute of Agrobiological Resources in Japan. Major agronomic characteristics including the activity of nitrogen fixation for root nodules during the grain filling period were measured. Measurements during the stages were followed by the stage of development descriptions for soybeans made by Fehr and Carviness (1977). The acetylene reducing activity (ARA) per dry weight of root nodule measured using acetylene reduction assays was the highest at R4-R4.5 with decreasing trends thereafter for the early matruing varieties, while it continuously increased up to R6 but decreased rapidly thereafter for the late maturing varieties. The dry weights of root nodules and all parts of the host plant at each stage checked were greater in the late maturing varieties being the same in ARA per pot.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.4
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• pp.298-303
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• 1981

A study was conducted to find out the varietal difference in some important agronomic characters in response to different seeding time in barely from 1975 to 1976 at Chikugo Agric. Expt. Station in Japan. Thirteen varieties which are diverse in growth period were used. Nine seeding time were tried. Seedling emergence, primary tillering, and formation of flower primodia were delayed in proportion to the seeding time. And also heading and maturing time showed the same tendency. This tendency appeared more conspicuous in the late maturing varieties. Therefore, days to heading and maturing duration were inversely shortened by the delay of seeding time and by earliness of variety. Number of spikes as well as culm length and spike length was reduced in the late seeding. Grain yield was reduced in all varieties by late seeding, easpecially with late maturing varieties. In this test, widely adaptable variety to late seeding time was not found, but earliness and high tillering in growth habit appeared more favorable to yield increase.