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Breeding and Development of the Tscherskia triton in Jeju Island (제주도 서식 비단털쥐(Tscherskia triton)의 번식과 발달)

  • Park, Jun-Ho;Oh, Hong-Shik
    • Korean Journal of Environment and Ecology
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    • v.31 no.2
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    • pp.152-165
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    • 2017
  • The greater long-tail hamster, Tscherskia triton, is widely distributed in Northern China, Korea and adjacent areas of Russia. Except for its distribution, biological characteristics related to life history, behavior, and ecological influences for this species are rarely studied in Korea. This study was conducted to obtain biological information on breeding, growth and development that are basic to species-specific studies. The study adopted laboratory management of a breeding programme for T. triton collected in Jeju Island from March, 2015 to December, 2016. According to the study results, the conception rate was 31.67% and the mice in the large cages had a higher rate of conception than those in the small cages (56.7 vs. 6.7%). The gestation period was $22{\pm}1.6days$ (ranges from 21 to27 days), and litter size ranged from 2 to 7, with a mean of $4.26{\pm}1.37$ in the species. The minimum age for weaning was between $19.2{\pm}1.4days$ (range of 18-21 days). There were no significant differences by sex between mean body weight and external body measurements at birth. However, a significant sexual difference was found from the period of weaning (21 days old) in head and body length, as well as tail length (HBL-weaning, $106.50{\pm}6.02$ vs. $113.34{\pm}4.72mm$, p<0.05; HBL-4 months, $163.93{\pm}5.42$ vs. $182.83{\pm}4.32mm$, p<0.05; TL-4 months, $107.23{\pm}3.25$ vs. $93.95{\pm}2.15mm$, p<0.05). Gompertz and Logistic growth curves were fitted to data for body weight and lengths of head and body, tail, ear, and hind foot. In two types of growth curves, males exhibited greater asymptotic values ($164.840{\pm}7.453$ vs. $182.830{\pm}4.319mm$, p<0.0001; $163.936{\pm}5.415$ vs. $182.840{\pm}4.333mm$, p<0.0001), faster maximum growth rates ($1.351{\pm}0.065$ vs. $1.435{\pm}0.085$, p<0.05; $2.870{\pm}0.253$ vs. $3.211{\pm}0.635$, p<0.05), and a later age of maximum growth than females in head and body length ($5.121{\pm}0.318$ vs. $5.520{\pm}0.333$, p<0.05; $6.884{\pm}0.336$ vs. $7.503{\pm}0.453$, p<0.05). However, females exhibited greater asymptotic values ($105.695{\pm}5.938$ vs. $94.150{\pm}2.507mm$, p<0.001; $111.609{\pm}14.881$ vs. $93.960{\pm}2.150mm$, p<0.05) and longer length of inflection ($60.306{\pm}1.992$ vs. $67.859{\pm}1.330mm$, p<0.0001; $55.714{\pm}7.458$ vs. $46.975{\pm}1.074mm$, p<0.05) than males in tail length. These growth rate constants, viz. the morphological characters and weights of the males and females, were similar to each other in two types of growth curves. These results will be used as necessary data to study species specificity of T. triton with biological foundations.

Effects of Recipient Oocytes and Electric Stimulation Condition on In Vitro Development of Cloned Embryos after Interspecies Nuclear Transfer with Caprine Somatic Cell (수핵난자와 전기적 융합조건이 산양의 이종간 복제수정란의 체외발달에 미치는 영향)

  • 이명열;박희성
    • Reproductive and Developmental Biology
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    • v.28 no.1
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    • pp.21-27
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    • 2004
  • This study was conducted to investigate the developmental ability of caprine embryos after somatic cell interspecies nuclear transfer. Recipient bovine and porcine oocytes were obtained from slaughterhouse and were matured in vitro according to established protocols. Donor cells were obtained from an ear-skin biopsy of a caprine, digested with 0.25% trypsin-EDTA in PBS and primary fibroblast cultures were established in TCM-199 with 10% FBS. The matured oocytes were dipped in D-PBS plus 10% FBS + 7.5 $\mu$ g/ml cytochalasin B and 0.05M sucrose. Enucleation were accomplished by aspirating the first polar body and partial cytoplasm which containing metaphase II chromosomes using a micropipette with an out diameter of 20∼30 $\mu$m. A Single donor cell was individually transferred into the perivitelline space of each enucleated oocyte. The reconstructed oocytes were electric fusion with 0.3M mannitol fusion medium. After the electrofusion, embryos were activated by electric stimulation. Interspecies nuclear transfer embryos with bovine cytoplasts were cultured in TCM-199 medium supplemented with 10% FBS including bovine oviduct epithelial cells for 7∼9 day. And porcine cytoplasts were cultured in NCSU-23 medium supplemented with 10% FBS for 6 ∼8 day at $39^{\circ}C, 5% CO_2 $in air. Interspecies nuclear transfer by recipient bovine oocytes were fused with electric length 1.95 kv/cm and 2.10 kv/cm. There was no significant difference between two electric length in fusion rate(47.7 and 44.6%) and in cleavage rate(41.9 and 54.5%). Using electric length 1.95 kv/cm and 2.10 kv/cm in caprine-porcine NT oocytes, there was also no significant difference between two treatments in fusion rate(51.3 and 46.1%) and in cleavage rate(75.0 and 84.9%). The caprine-bovine NT oocytes fusion rate was lower(P<0.05) in 1 pulse for 60 $\mu$sec(19.3%), than those from 1 pulse for 30 $\mu$sec(50.8%) and 2 pulse for 30 $\mu$sec(31.0%). The cleavage rate was higher(P<0.05) in 1 pulse for 30 $\mu$sec(53.3%) and 2 pulse for 30 $\mu$sec(50.0%), than in 1 pulse for 60 $\mu$sec(18.2%). The caprine-porcine NT oocytes fusion rate was 48.1% in 1 pulse for 30 $\mu$sec, 45.2% in 2 pulse for 30 $\mu$sec and 48.6% in 1 pulse for 60 $\mu$sec. The cleavage rate was higher(P<0.05) in 1 pulse for 30 $\mu$sec(78.4%) and 1 pulse for 60 $\mu$sec(79.4%), than in 2 pulse for 30 $\mu$sec(53.6%). In caprine-bovine NT embryos, the developmental rate of morula and blastocyst stage embryos were 22.6% in interspecies nuclear transfer and 30.6% in parthenotes, which was no significant differed. The developmental rate of morula and blastocyst stage embryos with caprine-porcine NT embryos were lower(P<0.05) in interspecies nuclear transfer(5.1%) than parthenotes(37.4%).

Comparison of Growth Characteristics and Productivity of Summer Forage Crops in Sihwa Reclaimed Land (시화 간척지에서 하계 사료작물의 초종 및 품종에 따른 생육특성 및 생산성 비교)

  • Kim, Jong Geun;Jeong, Eun Chan;Kim, Meing Joong;Li, Yan Fen;Kim, Hak Jin;Lee, Su Hwan
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.41 no.2
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    • pp.110-118
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    • 2021
  • This study was conducted to investigate the effects of species and varieties of summer forage crops on growth characteristics and productivity in Sihwa reclaimed land. The summer forage crops used in the trial were silage corn, sorghum×sudangrass hybrid(SSH), and proso millet. For each forage species, Gwangpyeongok(GPO), P15453, P1952 and P2088 were used for silage corn, and 877F, Green star, Honey chew, and Turbo gold cultivars were used for SSH. For proso millet, Ibaekchal, Geumsilchal and Manhongchal developed by the National Institute of Crop Science were used. Silage corn and SSH were sown on May 21, 2019 and proso millet on June 4, and harvested on September 2. There was no significant difference in plant and ear height of silage corn among varieties. P1543 was the highest and P2088 was the lowest in yield of silage corn, but there was no significant difference among treatments. Among the SSH, the plant height of 877F was the highest and Turbo gold variety had the smallest (p<0.05). As for the dry matter(DM) yields, 877F had the highest at 3,862 kg/ha and Green star had the lowest at 2,669 kg/ha (p<0.05). The fresh matter yield of proso millet was 15,778 kg/ha, which was higher than that of corn or SSH, The average dry matter yield was 4,780 kg/ha, and Ibaekchal variety had the highest DM yield compared to other varieties (p<0.05). P2088 had the highest TDN content and GPO was the lowest (p<0.05). As for the SSH, the TDN content of Green star and Honey chew varieties was significantly higher, and the RFV value was the lowest in Turbo gold. The average crude protein content of proso millet was 7.03%, and the highest TDN and RFV values were 64.36% and 106 in Geumsilchal. In the experiment of the germination rate of summer forage crops according to salt concentration, silage corn showed a germination rate of 83.1% even at 0.4% salinity. In particular, P2088 and P1921 varieties had more than 80% germination rate even at 0.6% salt concentration. As for the SSH, the germination rate of 877F was 93.3% even at 0.8% salinity, and 88.3% with Honey chew, indicating higher resistance to salt concentration compared to other varieties. Proso millet showed a high germination rate of 84.0 to 88.7% even at a salt concentration of 0.6%. Considering the above results, proso millet was recommended as the most suitable forage crop species in the Sihwa reclaimed land with high salt concentration, and the Ibaekchal variety is recommended as a suitable forage crop due to its high yield.

Understanding Human Nobility Epoch, the Prerequisite of the Era of Resolution of Grievances (해원시대를 전제하는 인존시대에 대한 이해)

  • Park, Yong-cheol
    • Journal of the Daesoon Academy of Sciences
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    • v.27
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    • pp.135-169
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    • 2016
  • While examining the religious ideas implied by Jeungsan's Great Works of the Reordering of Universe, we find special ideas which cannot be found in any other religions, and these ideas are presented in diverse ways. Most of all, the representative idea is that of human nobility; a distinctive idea which makes Daesoonjinrihoe different from other religions. Thus, this research focuses on the following questions: when was Human Nobility concretely realized? What kind of organic relationship does human nobility have between the divine world and the world of humanity? In light of the forthcoming Era of Human Nobility, what are some concrete images which can be drawn from the interaction between the realms of heaven and humanity wherein preordinations are plotted in heaven and then carried out by humankind? Prior to formulating my own sense of the subject matter, I consulted 43 previous discussions and dissertations and arranged them chronologically so as to examine their correlation. From these sources and my own insights, I was able to gain a sense of the starting point of the era of human nobility and its tenor. I have found the following problems in previous research on the uniqueness and distinctness of human nobility: ①The conceptual undertones of human nobility have not been adequately gleaned. ②There do not seem to be any dissertations which examine the way in which human nobility is connected with the doctrines of the creative conjunction between yin and yang, the harmonious union of divine beings and human beings, and the resolution of grievances for mutual beneficence. ③In most dissertations, not only is the starting point of the Era of Human Nobility regarded as concurrent with the start of the 50,000 years of earthly paradise in the Later World, but also the point of division between the former world and the later world is widely disputed. ④In-depth and fully realized studies dealing with the subject of human nobility are not easily found. ⑤There is little sense of progression in the research on human nobility because scholars are not sufficiently engage with one another to achieve common consensus. Therefore, in this dissertation, I have provided answers to the problems I discovered in previous research. I have developed my own tenor as follows: ①By giving priority to the Jeongyeong, I have closely investigated the period which divides the Former World and the Later World. Then, I produced a chronological timeline to demonstrate the progression: the Former World → the Era of the Resolution of Grievances → the Later World. This aids in the comprehension of human nobility. ②The Era of Human Nobility was preceeded by the opening of the Era of the Resolution of Grievances of human world which began in 1901. Human nobility is stipulated as a regulatory system for the universe set in motion by the opening the Era of Resolution of Grievances. ③While synthetically examining the aspects of transition which enable the Ear of Human Nobility to be realized, the period to be studied is stipulated as beginning from 1901 and ending at the start of the Later World. The subjects are defined as the flowing from Jeungsan, the first leader of human nobility, to the noble individuals empowered by Dao and the noble populace. In the Era of Human Nobility, studying the transition process by which human nobility is realized requires delving into the resolution of grievances. Although this method is essential to understanding Daesoon ideas, in actuality it does not hinge upon speculative exegetical theorizing but instead it was gained through eisegetical rigor.

A Study on medical Qigong mentioned in ${\ll}$Samilshingo${\gg}$ (三一神誥) (${\ll}$삼일신고(三一神誥)${\gg}$에 나타난 의료기공(醫療氣功)에 관(關)한 연구(硏究))

  • Ban, Chang-Yul
    • Journal of Korean Medical Ki-Gong Academy
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    • v.7 no.2
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    • pp.40-94
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    • 2004
  • Recently, meditation, Zen meditation and Qigong became popular in western. For that reason, Value of Korea traditional methods for health promotion have been evaluated but theoretical evidence about that is insufficient. ${\ll}$The Yellow Emperor's Inner Classic${\gg}$ (黃帝內經). So, I reviewed history of Korea Qigong according to period, in order to produce theoretical evidence of Korea medical Qigong and investigated ${\ulcorner}$Han${\lrcorner}$ thought (${\ulcorner}$${\lrcorner}$ 思想) as theoretical evidence of Korea Qigong. I have obtained following results by comparing meaning of god, a view of human body and practice method of the ${\ll}$Samilshingo${\gg}$ (三一神誥) with ${\ll}$The Yellow Emperor's Inner Classic${\gg}$ (黃帝內經). Sinsundo(神仙道) of native to race became active during the period of the Three Kingdoms but more disappeared due to under the influence of Taoism. So only has been remained in existence since the period of the unity silla. There could accept positively the foreign ideas belonging to Confucianism, Buddhism and Taoism have been brought since the period of the Three Kingdoms because ${\ll}$Samilshingo${\gg}$ (三一神誥), one of three the scriptures as the origin of ${\ulcorner}$Han${\lrcorner}$ thought(${\ulcorner}$${\lrcorner}$ 思想) included the original form of three religion belonging to Confucianism, Buddhism, Taoism. Three common results as theoretical evidence of Qigong were found out by comparing ${\ll}$Samilshingo${\gg}$ (三一神誥) with ${\ll}$The Yellow Emperor's Inner Classic${\gg}$ (黃帝內經). First, in meaning of god, there is not only different from the gods of heaven and the gods of human but also keep understanding with each other and there was common feature of logical structure that function of god was divided into three. Second, In a view of human body, there were in common with ${\ll}$Samilshingo${\gg}$ (三一神誥) as theory of only as energy(氣一元論), theory of bisection as truth false(眞妄二分論), theory of trisection as spirit(性) destiny(命) nature(精) and mind(心) energy(氣) body(身)(性 命 精, 心 氣 身의 三分論) and ${\ll}$The Yellow Emperor's Inner Classic${\gg}$ (黃帝內經) as theory of only as energy(氣一元論), theory of bisection as shape and god(形神二分論), theory of trisection as nature(精) energy(氣) god(神) or shape(形) energy(氣) god(神)(精 氣 神, 形 氣 神의 三分論) according to formal part. Also, spirit(性) destiny(命) nature(精) as truths of three(三眞) were understand as nature(精) energy(氣) god(神) as treasure of three(三寶) by part of reason and mind(心) energy(氣) body(身) as false of three(三妄) were understand as nature(精) energy(氣) god(神) as treasure of three(三寶) by part of function. Third, In practice method, pause of thinking(止感) modulation of breath(調息). prohibition of sensibility(禁觸) mentioned in ${\ll}$Samilshingo${\gg}$ (三一神誥) as practice method each were understand regulation of an etiological cause as an internal cause, an external cause and not internal and external cause in oriental medicine. Namely, pause of thinking(止感) was understand as regulation method of emotion, mind and nature. modulation of breath(調息) was not only as modulation of energy from the inner parts of the body but also that from the internal and external parts of the body, prohibition of sensibility(禁觸) was understand as regulation method of ear, eye, mouth, and nose and posture, life style. These results suggest that ${\ll}$Samilshingo${\gg}$ (三一神誥) is worth meaning of Korea medical Qigong because meaning of god, a view of human body, practice method of mentioned in ${\ll}$Samilshingo${\gg}$ (三一神誥) is common with that of ${\ll}$The Yellow Emperor's Inner Classic${\gg}$ (黃帝內經) as theoretical evidence of Qigong.

Studies on the Productivity of Individual Leaf Blade of Paddy Rice (수도의엽신별 생육효과에 관한 연구)

  • Dong-Sam Cho
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.18
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    • pp.1-27
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    • 1975
  • Experiment I: A field experiment was conducted in an attempt to find the effect of top-dressing at heading time in different levels of nitrogen application and of different positioned leaf blades formed by the treatment of leaf defoliation at heading time on the ripening and the yield of rice. The results obtained are as follows: 1. Average number of ears per hill and average number of grains per ear in different levels of nitrogen application were increased as the amount of nitrogen applied was increased. while the rate of ripened grains the yield of rough rice and the weight of 1, 000 kernels of brown rice were decreased respectively as the amount of nitrogen applied was increased. 2. The rate of ripened grains and the weight of 1.000 kernels of brown rice in different levels of nitrogen, top-dressing at heading time were larger than those in control and increased. The yield of rough rice although statistically significant differences were not recognized, were numerically increased. 3. The rate of ripened grains, the yield of rough rice, the weight of 1, 000 kernels of brown rice and the rate of hulling in different treatments of leaf defoliation were remarkably decreased as the degree of leaf-defoliation became larger. 4. The rate of ripened grains, the yield of rough rice, the weight of 1, 000 kernels of brown rice and the rate of hulling in different combinations of number of remained leaves positioned differently, formed the order of $L_1(flag leaf)>L_2>L_3>L_4$ when only one leaf blade was remained, and were increased as the positions of leaves were higher when two leaf blades. were, remained. 5. In case of decrease in the number of leaf blades positioned differently, by the treatment of leaf. defoliation, rate of ripened grains, the yield of rough rice, the weight of 1, 000 kernels of brown rice and the rate of hulling were increased as the area of remained leaves became larger and the nitrogen content of a leaf blade was increased. 6. There was a tendency that the increase in the amount of fertilizer application made the rate of ripened grains and the weight of 1, 000 kernels of brown rice reduced in any number of remained leaf blades, but the application of top-dressing at heading. time resulted in the reverse tendency. The yield of rough rice showed a tendency to be increased as the amount of basal dressing and top-dressing increased and for the application of top-dressing at heading time, the yield of rough rice was less at the smaller number of those. 7. The productivity effect of the rate of ripened grains and the yield of brown rice covered by leaf blades was more than 50 per cent and that of the. weight of 1, 000 kernels of brown rice was not more than 1.0 percent. As the amount of nitrogen application increased the. effect of leaf blades on the rate of ripened. grains and the weight of 1, 000 kernels of brown rice was increased. The effect of leaf blades on the weight of brown rice was increased as the amount of basal dressing-application, but the effect was decreased as the amount of top-dressing at heading time increased, 8. The productivity effects of different positioned leaf blades on the rate of ripened grains, the yield of rough rice and the weight of 1, 000 kernels of brown rice were in order of $L_1(flag leaf)>L_2>L_3>L_4$ the productivity effects of $L_1$ and $L_2$ had a tendency to be increased as the amount of nitrogen applied was increased. Experiment II: A field experiment was done in order to disclose the effect of the time of nitrogen application on yield component and the effect of different positioned leaves formed by leaf defoliation at heading time on the rate of ripened grains and the yield of rice. The results obtained are as follows: 1. Average number of ears per hill was increased in the treatment of nitrogen application from basal dressing to 22 days before heading and in the treatment of application distributed weekly. Number of grains was increased in the treatment of nitrogen application from 36 days to 15 days before heading. The rate of ripened grains was, lower in the treatment of nitrogen application from top-dressing to 15 days before heading than in that of non-application, was higher in the treatment of nitrogen application within 8 days before heading, and was the lowest in that of application 29 days before heading. The yield of rough rice was the highest in the treatment of nitrogen application from 29 days to 22 days before heading. The weight of 1, 000 kernels of brown rice was a little high in the treatment of application from 29 days to 8 days before heading. 2. The rate of ripened grains the yield of rough rice, the weight of 1, 000 kernels of brown rice and the rate of hulling in different treatments of leaf defoliation were remarkably decreased as the degree of leaf defoliation got larger and there were highly significant differences among treatments. There was also a recognized interaction between the time of nitrogen application and leaf defoliation. 3. In relation to the rate of ripened grains, the weight of 1. 000 kernels of brown rice and the rate of hulling in different numbers of remained leaves positioned differently and their combinations, the yield components were in order of $L_1(flag leaf)>L_2>L_3>L_4$ when only one leaf was remained, which indicated that the components were increased as the leaf position got higher. When two laves were remained, the rate of ripened grains, the yield of rough rice and rate of hulling were high in case of the combinations of upper positioned leaves, and the increase in the weight of 1, 000 kernels of brown rice appeared to be affected most]y by flag leaf. When three leaf blades were remained similarly the components were increased with the combination of upper positioned leaf blades. 4. In case of decreased different positioned leaf blades by treatment of leaf defoliation, there was a significant positive regression between the leaf area, the dry matter weight of leaf blades and the nitrogen contents of leaf blades, and rate of ripened grains and the yield of rough rice, but there was no constant tendency between the former components and the weight of 1. 000 kernels of brown rice. 5. The closer the time of fertilizer application to heading time, the more the rate of ripened grains and the weight of 1, 000 kernels was decreased by defoliation, and the less were the remained leaf blades, the more remarkable was the tendency. The rate of ripened grains and the weight of 1. 000 kernels was increased by the top-dressing after heading time as the number of remained leaf blades. When the number of remained leaf blades was small the yield of rough rice was increased as the time of fertilizer application was closer to heading time. 6. Discussing the productivity effects of different organs in different times of nitrogen application, the productivity effect of a leaf blade on the rate of ripened grains was higher as the time of nitrogen application got later, and in the treatment of non-fertilization the productivity effect of a leaf blade and that of culm were the same. In the productivity effect on the yield of brown rice, the effect of culm covered more than 50 percent independently on the time of nitrogen application, and the tendency was larger in the treatment of non-fertilizer. The productivity effect of culm on the weight of 1. 000 kernels of brown rice was more than 90 percent, and the productivity effect of a leaf blade was increased as the time of application got later. 7. The productivity effect of a leaf blade in different positions on the rate of ripened grains, the yield of rough rice and the weight of 1, 000 kernels of brown rice had a tendency to be increased as the time of application got later and as the position of leaf blades got higher. In the treatment of weekly application through the entire growing period, the rate of ripened grains and the yield of rough rice were affected by flag leaf and the second leaf at the same level, the but the weight of 1, 000 kernels of brown rice was affected by flag leaf with more than 60 percent of the yield of total leaves.

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Studies on Ecological Variation and Inheritance for Agronomical Characters of Sweet Sorghum Varieties (Sorghum vulgare PERS) in Korea (단수수(Sorghum vulgare PERS) 품종의 생태변이 및 유용형질의 유전에 관한 연구)

  • Se-Ho Son
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.10
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    • pp.1-43
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    • 1971
  • Experiment I: The objective of this study was to know variation in some selected agronomic characters of sweet sorghum when planted in several growing seasons. The 17 different sweet sorghum varieties having various maturities, and plant, syrup and sugar types were used in this study which had been carried out for the period of two years from 1968 to 1969 at Industrial Crops Division of Crop Experiment Station in Suwon. These varieties were planted at an interval of 20 days from April 5 to August 25 both in 1968 and 1969. The experimental results could be summarized as follows: 1. As planting was made early, the number of days from sowing to germination was getting prolonged while germination took place early when planted at the later date of which air temperature was relatively higher. However, such a tendency was not observed beyond the planting on August 25. In general, a significant negative correlation was found between the number of days from sowing to germination and the average daily temperature but a positive correlation was found between the former and the total accumulated average temperature during the growth period. 2. The period from sowing to heading was generally shortened as planting was getting delayed. The average varietal difference in number of days from sowing to heading was as much as 30.2 days. All the varieties were grouped into early-, medium and late-maturing groups based upon a difference of 10 days in heading. The average number of days from sowing to heading was 78.5$\pm$4.5 days in the early-maturing varieties, 88.5$\pm$4.5 days in the medium varieties and 98.5$\pm$4.5 days in the late-maturing varieties, respectively. The early-maturing varieties had the shortest period to heading when planted from July 15 to August 5, the medium varieties did when planted before July 15 and the late-maturing varieties did when planted before June 5. 3. The relationship between the sowing date (x) and number of days from sowing to heading could be expressed in an equation of y=a+bx. A highly positive correlation was found between the coefficient of the equation(shortening rate in heading time) and the average number of days from sowing to heading. 4. The number of days from sowing to heading was shortened as the daily average temperature during the growth period was getting higher. Early-maturing varieties had the shortest period to heading at a temperature of 24.2$^{\circ}C$, medium varieties at 23.8$^{\circ}C$ and late-maturing varieties at 22.9$^{\circ}C$, respectively. In other words, the number of days from sowing to heading was shortened rapidly in case that the average temperature for 30 days before heading was 22$^{\circ}C$ to $25^{\circ}C$. It prolonged relatively when the temperature was lower than 21$^{\circ}C$. 5. There was a little difference in plant height among varieties. In case of early planting, no noticeable difference in the height was observed. The plant height shortened generally as planting season was delayed. Elongation of plant height was remarkably accelerated as planting was delayed. This tendency was more pronounced in case of early-maturing varieties rather than late-maturing varieties. As a result, the difference in plant height between the maximum and the minimum was greater in late-maturing varieties than in early-maturing varieties. 6. Diameter of the stalk was getting thicker as planted earlier in late-maturing varieties. On the other hand, medium or early-maturing varieties had he thickest diameter when they were planted on April 25. 7. In general, a higher stalk yield was obtained when planted from April 25 to May 15. However, the planting time for the maximum stalk yield varied from one variety to another depending upon maturity of variety. Ear]y-maturing varieties produced the maximum yield when planted about April 25, medium varieties from April 25 to May 15 and late-maturing varieties did when planted from April 5 to May 15 respectively. The yield decreased linearly when they were planted later than the above dates. 8. A varietal difference in Brix % was also observed. The Brix % decreased linearly when the varieties were planted later than May 15. Therefore, a highly negative relationship between planting date(x) and Brix %(y) was detected. 9. The Brix % during 40 to 45 days after leading was the highest at the 1st to the 3rd internodes from the top while it decreased gradually from the 4th internode. It increased again somewhat at the 2nd internode from the ground level. However, it showed a reverse relationship between the Brix % and position of internode before heading. 10. Sugar content in stalk decreased gradually as planting was getting delayed though one variety differed from another. It seemed that sweet sorghum which planted later than June had no value as a sugar crop at all. 11. The Brix % and sugar content in stalk increased from heading and reached the maximum 40 to 45 days after heading. The percentage of purity showed the same tendency as the mentioned characters. Accordingly, a highly positive correlation was observed between. percentage of purity and Brix % or sugar content in stalk. 12. The highest refinable sugar yield was obtained from the planting on April 25 in late-maturing varieties and from that on May 15 in early-maturing varieties. The yield rapidly decreased when planted later than those dates. Such a negative correlation between planting date(x) and refinable sugar yield(y) was highly significant at 1% level. 13. Negative correlations or linear regressions between delayed planting and the number of days from sowing to germination. accumulated temperature during germination period, number of days to heading, accumulated temperature to heading, plant height, stem diameter, stalk weight, Brix %. sugar content, refinable sugar yield or Purity % were obtained. On the other hand, highly positive correlations between the number of days from sowing to heading(x) and Brix %, sugar content, purity %, refinable sugar yield, plant height or stalk yield, between Brix %(x) and purity %, refinable sugar yield or stalk yield, between sugar content(x) and purity% or refinable sugar yield(y), between purity %(x) and refinable sugar yield and between daylength at heading(x) and Brix %. number of days from sowing to heading, sugar content, purity % or refinable sugar yield (y), were found, respectively. Experiment II: The 11 varieties were selected out of the varieties used in Experiment I from ecological and genetic viewpoints. Complete diallel cross were made among them and the heading date, stalk length, stalk yield, Brix %, syrup yield, combining ability and genetic behavior of F$_1$ plants and their parental varieties were investigated. The results could be summarized as follows: 1. In general, number of days to heading showed a partial dominance over earliness or late maturity or had a mid-value, though there were some specific combinations showing a complete dominance or transgressive segregation in maturity. Some combinations showed relatively high general or specific combining abilities in maturity. Therefore, a 50 to 50 segregation ratio in heading date could be estimated in this study and it might be positive to have a selection in early generation since heritability of the character was relatively high. 2. A vigorous hybrid vigor was observed in stalk length. A complete or partial dominant effect of long stalk was obtained. The general combining ability and specific combining ability of stalk length were generally high. Long and short stalks segregated in a ratio of 50:50 and its heritability was relatively low. 3. Except for several specific combinations, high stalk yield seemed to be partial dominant over the low yield. Some varieties demonstrated relatively high general as well as specific combining abilities. It was assumed that several recessive genes were involved in expression of this character. The interaction among regulating recessive genes was also obtained. Accordingly, the heritability of stalk yield seemed to be rather low. 4. The Brix % of hybrid plants located around mid-parental value though some of them showed much higher or lower percentage. It could be explained by the fact that such behavior might be due to partial dominance of Brix %. The varieties with, relatively higher Brix % were high both in general. and specific combining abilities. Therefore, it could be recommended to use the varieties having higher sugar content in order to develop higher-sugar varieties. 5. The syrup yield seemed to be transgressively segregated or completely dominant over low yield. Hybrid vigor of syrup yield was relatively high. No-consistent relationship between general combining ability and specific combining ability was observed. However, some cases demonstrated that the varieties with relatively higher general combining ability had relatively lower specific combining ability. It was assumed that the frequencies of dominant and recessive alleles were almost same.

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