• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.3
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• pp.214-219
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• 1991

To clarify the relationship between ambient water temperature and heading characteristics of rice (Oryza sativa L.), twelve of varieties rice were grown in a cold tolerance screening field where water temperature was controlled by continuous cold water irrigation system to test the cold tolerance of rice. When cold water was continuously irrigated with 5 cm of water depth, the water had stagnated for about three hours, and the water temperature increased gradually from inlet toward outlet in the experimental plot. The fluctuation of water temperature was well synchronized with that of ambient air temperature, and the water temperature near outlet became higher than the air temperature at the vegetative phase, while became lower at the reproductive phase of rice plant community. The leaf development rates on main culm increased by increased water temperature. The rice varities, Fukuhikari, Sangpungbyeo and YR3486-16-2 were more sensitive than the others in the response of leaf development to water temperature. However, Janack and Milyang 42 were comparatively less sensitive to water temperature in leaf development. Janack and Paro -white rices required longer days to develop one leaf on main culm at reproductive phase than at vegetative phase. Varietal difference in days required to develop one leaf on main culm of rice plant was more distinctive at the reproductive phase when water temperature was relatively lower than at the vegetative phase with relatively higher water temperature condition. No difference was found between the growth phases, vegetative and reproductive, in the response of average leaf developmental rates to water temperature under the similar air temperature condition. The estimated average days required to develop one leaf on main culm decreased by 1.3 day by 1$^{\circ}C$ increase in water temperature. Varietal differences in the total number of leaves on main culm depended upon the water temperature, in which the varieties such as Fukuhikari, Gwangmyeon-gbyeo, China 988, and YR3486-16-2 showed increased one leaf by increased water temperature, while Sobaekbyeo, Paro-white, Sangpungbyeo, Pungsanbyeo, Samgangbyeo, and Milyang 42 were kept at the same leaf number regardless of water temperature. However, the total leaf number on main culm and days to heading of Janack increased by increased water temperature. The other varieties showed the shortened days to heading by the increase in water temperature with noticeable varietal differences regardless of the variation in the total number of leaves on main culm.

• Molecules and Cells
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• v.25 no.1
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• pp.70-77
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• 2008

Proteome analysis was performed to identify proteins differentially expressed in an Arabidopsis mutant, ntm1-D. In this mutant the NAC transcription factor NTM1 is constitutively expressed and the resultant phenotypic changes include dwarfism, serrated leaves, and altered floral structures, probably due to reduced cell division. Marked elevation of proteins mediating environmental stress responses, including annexin, vegetative storage proteins, beta-glucosidase homolog 1, and glutathione transferases was observed. Overexpression of annexin was confirmed by RT-PCR and Western blotting. These observations suggest that the reduced growth observed in the ntm1-D mutant is caused by enhancement of its stress responses, possibly resulting in a cost in fitness.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.6
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• pp.548-558
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• 1990

Physiology and genetics of early maturity in cereals are the subject of practical as well as scientific interest for agronomist and plant breeders, Thorough understanding of the true nature of such a complex character requires physiological and genetical knowledge about the internal factors, which are closely bound up with and react to some particular external or environmental factors. From the practical point of view. experiments should be conducted under controlled conditions. especially the day length and temperature, so that the genotypic differences pertaining to these factors may be discerned. Takahashi and Yasuda (1958, 1970) maintained that at least three physiological factors were responsible for determining earliness in barley. namely. (1) spring and winter habit of growth or vernalization requirement, (2) ogitioeruiduc response or sensitivity to short-day, and (3) earliness factor in a narrow sense or minimal vegetative growth. The same situations were true in common wheat also (Yasuda and Shimoyama, 1965), In this report. physiology and genetics of internal factors and their relations to the time of heading in the field will be presented with some problems concerning differences in mechanism of early maturity between barley and wheat.

• Molecules and Cells
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• v.39 no.10
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• pp.715-721
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• 2016

Plants have become physiologically adapted to a seasonally shifting environment by evolving many sensory mechanisms. Seasonal flowering is a good example of adaptation to local environmental demands and is crucial for maximizing reproductive fitness. Photoperiod and temperature are major environmental stimuli that control flowering through expression of a floral inducer, FLOWERING LOCUS T (FT) protein. Recent discoveries made using the model plant Arabidopsis thaliana have shown that the functions of photoreceptors are essential for the timing of FT gene induction, via modulation of the transcriptional activator CONSTANS (CO) at transcriptional and post-translational levels in response to seasonal variations. The activation of FT transcription by the fine-tuned CO protein enables plants to switch from vegetative growth to flowering under inductive environmental conditions. The present review briefly summarizes our current understanding of the molecular mechanisms by which the information of environmental stimuli is sensed and transduced to trigger FT induction in leaves.

• Journal of Bio-Environment Control
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• v.18 no.2
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• pp.142-147
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• 2009

The effects of short-term waterlogging on physiological responses, fatty acid compositions and yield components of rapeseed at both the vegetative growth and the reproductive growth stages were assessed in this study. Waterlogged plants were treated for a period of 10 days at the vegetative growth stage and 4 days at the reproductive growth stage. The results show that photosynthesis and stomatal conductance at both the vegetative growth and the reproductive growth stage were significantly reduced during the waterlogging period and after the recovery period. When the plants were removed from water, photosynthesis and stomatal conductance progressively restored similar values to those of control plants within $2{\sim}3$ days. Fatty acid compositions were unaffected by waterlogging treatment. However, yield components (pod number and pod length) of the waterlogged treated plants at the reproductive growth stage were significantly reduced. These results suggest that short-term waterlogging may thus influence oilseed yield component.

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.11a
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• pp.28-45
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• 2000

It was unusual crop weather for 1998 and 1999 compared with normal in Korea. The consecutive days of the optimum ripening period for rice plant that had daily mean temperature 21-23C for 40 days after heading, increased with long anomalies in 1998-99. The air temperature during ripening period was much higher than the optimum temperature and lower sunshine hour than normal in the local adaptability tests of newly developed rice lines during those years. In response of rice cultivation to warming and cloudy weather during crop season, the yield shall be decreased. Most scientists agree that the rate of heating is accelerating and temperature change could become increasingly disruptive. Weather patterns should also become more erratic. Agrometeorologists could be analyzed yearly variations of temperature, sunshine hour and rainfall pattern focused on transient agroclimate change for last a decade. Rice agronomists could be established taking advantage of real time agricultural meteorology information system for fertilization, irrigation, pest control and harvest. Also they could be analyzed the characteristics of flowering response of the recommended and newly bred rice cultivars for suitable cropping plan such as cultural patterns and sowing or transplanting date. Rice breeders should be deeply considered introducing the characteristics of basic vegetative type of flowering response like Tonsil rices as prospective rice cultivars corresponding to global warming because of the rices needed higher temperature at ripening stage than Japonica rices, photoperiod sensitive and thermo-sensitive ecotypes

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.4
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• pp.273-278
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• 1998

Carbohydrate metabolism and partitioning are dependent on relationships between sources and sinks which can be affected by rates of photosynthesis and respiration. Fructan, the major form of stored carbohydrate in tall fescue (festuca arundineacea Schreb.), changes in concentration during growth and in response to the environment. Objectives of this study were i) to examine the content and the composition of carbohydrates in five tissues (mature leaf blade, immature leaf blade, leaf elongation zone, terminal meristem, and root tips) of two tall fescue genotypes, one with high yield per tiller (HYT) and one with low yield per tiller (LYT), and ii) to compare the reserved and utilized carbohydrates among above five different tissues, particularly between the leaf elongation zone and root tips. The established vegetative tillers of the HYT and LYT genotypes were grown in a controlled-environment growth chamber. Water-soluble carbohydrate (WSC) in the leaf elongation zone was about 22% of dry weight in the HYT and about 19% in the LYT genotype. The root tip also had high WSC, about 12% of dry weight in the HYT and 6% in the LYT genotype. Hexoses and sucrose were the major components of total WSC in all tissues except the leaf elongation zone. The growing tissues (sinks), i.e., the leaf elongation zone and root tip, had a high proportion of low degree of polymerization fructan, i.e., 3 to 8 hexose units.

• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.3
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• pp.162-168
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• 1991

Iterbicide resduc. cauicd ~rljul-y to ovcrsown pasture grasses \\hen herbicide appliccl for use in pasturc est;~blish~nt~nt lo gro~vth contro! ol n;rtivc ~r ~:cds and shrubs. 'l'hih L~sperirnel~t was conducted to cv;lluati. (he herbicidr residue anti its ph!:totosical ~riiiuence on the growth of introtluccd pasturts species. Esperimcmtal soils was treated with buthitlazolc, ~ o d l ~ l m chlorate, glyphosatc. U-46 anti paraquat each at twt) applici~tion rates. Lhcf~1i.s glowl~mlc~ including othrr pasture grasses and le~urnes were evaluatrd for tolerance to herbicide. IIerbicide residue in the amount ot injury caused to introduced pasture grasses was found in order of buthidazole, sodium chlorate, U-46 and glyphosate. Euthidazole was not available for use in pasture establishment because of their long persist of toxic herbicide residues. A great stand redl~ction of subseq ~ ~ c n t oversown pastures was also observed In sodium chlorate treatment. However, normal vegetative stand and grass production was obtained, when thc pasture grasses seeded 45-60 days later herbicide treatments. Glyphosate did not affect subsequent oversown pasture species in both grasses and legumes. fistuccr arundinc~cea and Pou pratensis were the most tolerant pasture species to herbicide residue while 7'rzfi,lium pyatense and Medicugo suti~u showed a wsceptible response regardless of herbicide.

• Plant Resources
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• v.5 no.2
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• pp.155-160
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• 2002

The heading date is known to be controlled by two kinds of genetic constituent, photosensitivity and basic vegetable phase. For the latter, the effect of temperature in early growth period is critical to determine the shortness of vegetative growth periods in plant's life. A phytotron experiment on 55 rice cultivars, consisting of two ecotypes of rices, indica and japonica, was conducted at high and low temperature treatments at early growth stage to investigate the possible role of plant growth stimulus by high temperature to associate with shortening of heading date. The high temperature during the early growth stage stimulated the rice growth as measured by plant height with much difference of the growth response between indica and japonica. The conclusive finding that these growth stimulus in early growth stage was highly correlated with the acceleration of heading is, more or less, correlated with the heading of the late growth stage although we could not conclude the genes for early plant growth stimulus by high temperature is the same genes as the genes for accelerating of heading in the late growth stage of plants.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.2
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• pp.81-88
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• 2003

Soybeans [Glycine max (L.) Merr.] are frequently exposed to unfavorable environments during growing seasons and water is the most important factor limiting for the production system. The purpose of this study was to determine the leaf water potential changes by irrigation, and to evaluate the relationships of leaf water potential, growth and yield in soybeans. Three soybean cultivars, Hwangkeumkong, Shinpaldalkong 2, and Pungsannamulkong, were planted in growth chamber and field with irrigated treatments. Leaf water potential of three soybean cultivars was positively correlated with leaf water content during vegetative and reproductive growth stages in growth chamber and field experiments. Leaf water potentials measured for three soybean cultivars under growth chamber were higher than those of under field conditions. Higher leaf water potential with irrigated plots under field was observed compared to conventional plots during reproductive growth stages. Leaf water potentials of three soybean cultivars were continually decreased during reproductive growth stages under field and there was no significant difference among them. Number of leaves, leaf water content, pod dry weight, number of seeds and seed dry weight with irrigated plots were higher than those of conventional plots. The results of this study suggested that leaf water potential could be used as an important growth indicator during the growing season of soybean plants.