Development of a Seedling Screening Method for Low-Temperature Tolerance in Pumpkin (Cucurbita moschata) and Selection of the Tolerant Resources for Rootstock of Cucumber

유채린,Hemasundar Alavilli,송기환 한국육종학회 2022 Plant Breeding and Biotechnology Vol.10 No.2

Pumpkin (Cucurbita moschata) has been increasingly used as bloomless rootstock for cucumber (Cucumis sativus), butit is sensitive to low-temperature, which is the major bottleneck for winter cultivation. Hence, to develop low-temperature tolerantrootstock varieties, it is needed to identify tolerant germplasm from a wide range of genetic resources. For this, we developed a selectioncriterion for a quick assessment of low-temperature tolerance in pumpkin germplasms from different geographical origins. Weconsidered various indexes for the fast evaluation of low-temperature tolerance, including seedling developmental stage, type ofseedling (excised or non-excised), growth space, etc. Under the testing condition (17℃/7℃, 8 hours light/16 hours dark, 150 μmol m-2s-1light intensity), we found a correlation (r=0.71*) in root growth between 3 weeks-cultured excised seedlings and 6 weeks-culturednon-excised seedlings. Therefore, we extrapolate that excised cotyledonary stage seedling treated for 3 weeks is sufficient todifferentiate the tolerant germplasms. Using this screening method, we identified the “S81015” could prevail low-temperature stress. Further, we tested grafting compatibility and growth of grafted cucumbers under the low-temperature condition to assess the effect ofrootstock and identify low-temperature tolerant and grafting-compatible rootstock germplasm. Upon grafting, we found a highcorrelation (r=0.97**) between the root fresh weight of 6 weeks-cultured non-excised seedlings and the shoot fresh weight of thegrafted cucumbers. In summary, we could identify the low-temperature tolerant pumpkin germplasms by screening at the earlydevelopmental stage. Further, as a rootstock, the tolerant pumpkins also fortified the low-temperature tolerance of grafted cucumbers.

저온에서 벼의 발아율 및 발아속도 관련 양적형질 유전자좌(QTL) 분석

김진희,모영준,하수경,정지웅,정종민 한국작물학회 2021 한국작물학회지 Vol.66 No.1

As rice originates from tropical regions, low temperature stress during the germination stage in temperate regions leads to serious problems inhibiting germination and seedling establishment. Identifying and characterizing quantitative trait loci (QTLs) for low-temperature germination (LTG) resistance help accelerate the development of rice cultivars with LTG tolerance. In this study, we identified QTLs for LTG tolerance (qLTG5, qLTG9) and germination coefficient of velocity under optimal conditions (OGCV) (qOGCV7, qOGCV9) using 129 recombinant inbred lines (RILs) derived from the cross between a low-temperature sensitive line Milyang23 and a low-temperature tolerant variety Gihobyeo. qLTG9 and qOGCV9 were detected at the same location on chromosome 9. At both LTG QTLs (qLTG5 and qLTG9), the alleles for LTG tolerance were contributed by the japonica variety Gihobyeo. At qOGCV7 and qOGCV9, the alleles for low temperature tolerance were derived from Milyang23 and Gihobyeo, respectively. The RILs with desirable alleles at two or more QTLs, i.e., GroupVII: qLTG5+qLTG9 (qOGCV9) and GroupVIII: qLTG5+qOGCV7+qLTG9 (qOGCV9), showed stable tolerance under low-temperature stress. Our results are expected to contribute to the improvement of tolerance to low-temperature and anaerobic stress in japonica rice, which would lead to the wide adoption of direct-seeding practices. 자포니카 벼의 저온 스트레스 내성 증진을 위하여, RIL 계통을 이용하여 저온 스트레스 내성 QTL을 탐색하였다. 이를통하여 (1) 5, 9번 염색체에서 저온발아에 관련한 ‘기호벼’ 유래 QTL, qLTG5와 qLTG9를 확인하였으며, 7, 9번 염색체에서 저온 발아속도에 관련한 ‘밀양23호’ 및 ‘기호벼’ 유래 QTL, qOGCV7, qOGCV9를 확인하였다. (2) Duncan 검정결과, 그룹Ⅶ [qLTG5+qLTG9 (qOGCV9)], 그룹Ⅷ [qLTG5+ qOGCV7+qLTG9 (qOGCV9)]의 계통들이 저온 스트레스에내성이 있는 것으로 확인 되었다. (3) 최근 발표된 RIL 집단 담수내성 계통과 비교한 결과, 저온 스트레스에도 내성이 있으면서 담수발아에도 내성이 있는 것으로 확인된 총2개의 유망 유전자원을 선발하였다. 본 연구의 결과를 통해 저온 및 혐기 관련 QTL의 집적은벼의 저온에서의 발아 및 초기 입모율을 높여 저온스트레스 내성 개선에 도움이 되는 것으로 판단 되었으며, 선발된유망 계통은 향후 직파재배 품종 육성에 유용한 유전자원으로 활용되어 직파재배의 안정성 증대에 기여할 것으로기대된다.

저수온에 노출된 말쥐치 Thamnaconus modestus의 생존율, 혈액학적 및 조직학적 반응

김혜진,이희중,김원진,신윤경 한국어류학회 2019 韓國魚類學會誌 Vol.31 No.4

Temperature is one of the most important criteria considered in species preference for aquaculture. Acute drop in temperature during winter is a cause of disease and mass mortality in farmed fish. This study was carried out the low water temperature tolerance, oxygen consumption, hematologic and histological responses to use as basic data for the management of fish farming which frequently cause death due to winter water temperature drop. Low-lethal water temperature for 4 days of file fish Thamnaconus modestus (4day-LT50) was 6.97°C (6.69~7.27°C). Oxygen consumption rate decreased with decreasing water temperature, showing a significant difference between water temperatures. SOD activity increased significantly at 6°C experimental group than control group (10°C) (p<0.05), but CAT did not show any significant difference between experimental temperatures (p>0.05). Cortisol increased with decreasing experimental water temperature compared to control group. Histological changes in the liver include decreased blood vessels in the blood vessels, proliferation of acid cells, condensation of the nucleus, atrophy of pancreatic exocrine gland cells, and enzyme source granules. 수온은 양식어류의 생존에 영향을 미치는 가장 주요한 환경 요인이며, 겨울철 급작스런 수온하강은 양식어류의 질병과 집단폐사 발생의 요인이 되기도 한다. 본 연구는 겨울철 수온 하강으로 인해 빈번하게 폐사가 발생하고 있는 말쥐치의 양식관리를 위한 기초자료로 활용하기 위해 말쥐치의 하한수온내성 범위, 산소소비율, 혈액학적 및 조직학적 반응을 조사하였다. 수온 5°C에서 노출 3일째, 수온 6°C에서는 노출 4일째 모두 폐사하여 말쥐치의 저수온에 대한 반수치사 하한수온은 (LT50) 6.97°C (6.69∼7.27°C)였다. 산소소비율은 수온하강에 따라 감소하여 수온간 유의한 차이 (p<0.05)를 나타내었다. 혈액내 활성산소 소거효소인 SOD활성도는 대조구 10°C에 비해 수온 6°C에서 유의하게 상승하였다 (p<0.05). 반면 CAT는 실험수온 간에 유의한 변화를 나타내지 않았다 (p>0.05), 삼투질농도는 대조구와 실험수온간 유의한 차이는 나타나지 않았다 (p>0.05). 코티졸은 대조구에 비해 수온 하강에 따라 증가하였으며 수온 간 유의한 차이를 나타내었다 (p<0.05). 간의 조직학적 변화는 혈관내 혈구의 감소, 간세포의 공포화와 간세포 핵의 응축, 췌장 외분비 선세포의 위축 및 효소원과립들이 감소하였다.

돌돔(Oplegnathus fasciatus)의 생존, 산소소비 및 생리학적 반응에 미치는 저수온의 영향

신윤경,최영재,김원진 한국수산과학회 2020 한국수산과학회지 Vol.53 No.5

The sudden drop of water temperature in winter is very threatening factor that affects the productivity of farmed fish and the management in aquafarm. In this study, we investigated the effect of low temperature on the survival, oxygen consumption and stress responses of parrotfish Oplegnathus fasciatus due to acute drop of water temperature. The survival rate of parrotfish Oplegnathus fasciatus was 5% at 6°C, 95% at 8°C and 100% at 10°C on the 4th day of exposure in each experimental temperature. Low-lethal temperature for 4days of parrotfish Oplegnathus fasciatus (4 day-LT50) was 6.99°C (confidence limit, 6.55-7.42°C). Oxygen consumption rate was significantly decreased with decreasing water temperature. Temperature coefficient (Q10) was found to be 4.0 between 10°C and 8°C and 0.39 between 8°C and 6°C. As a result of investigating the stress response according to the drop in water temperature, the concentration of SOD (Superoxide dismutase), cortisol, glucose, total Ig, AST (Aspartate) and ALT (Alanine aminotransferase) increased with decreasing of water temperature. This study would be useful for the management of temperature about cultured fish.

An optimized index for cold tolerance assessment in rice during germination and early seedling stage

Monzón Daisy Leticia Ramirez,Cantero Jorge,Danielowski Rodrigo,da Luz Viviane Kopp,Venske Eduardo,Mota Monalize Salete,da Silva Raissa Martins,de Oliveira Victoria Freitas,de Oliveira Antonio Costa,de 한국작물학회 2023 Journal of crop science and biotechnology Vol.26 No.2

Cold tolerance at germination and seedling stage is one of the most seeked traits in Southern Brazilian rice (Oryza sativa L.) cultivars, thus, the availability of improved methods for germplasm assessment is of high importance for breeding programs. The aim of this study was to validate an optimized Average Tolerance Index (ATI) for rice germplasm assessment under cold at germination and early seedling stage. A diverse panel composed by 124 rice accessions was assayed. Four genotypes with known performance under cold were used as controls (two tolerant and two sensitive). The genotypes were sown in roll papers, and evaluated at 13 °C for 28 days (cold stress) and 25 °C for seven days (control). Four traits were measured, germination percentage, coleoptile length, root length and shoot length, which were converted in terms of relative perfor‑ mance (cold/control). A PCA analysis was carried out. The ATI was calculated as a linear combination of all trait’s relative performance, weighted by the importance of each trait in explaining the genetic variability in the set, through including the PC1 vectors as trait coefcients. K means was applied for genotype classifcation. The panel showed expressive genetic variability for performance under low temperature. The ATI successfully distinguished the controls regarding their cold tolerance and allowed the formation of four classes of genotypes, sensitive, moderately sensitive, moderately tolerant and tolerant. The assessment of rice germplasm for cold tolerance at germination and seedling stage through ATI is a viable alternative for the identifcation of tolerant genotypes.

Effect of Low Temperature on Heterosis for Traits Related to Cold Tolerance in Japonica Rice

안상낙,정응기,예종두 한국육종학회 2004 한국육종학회지 Vol.36 No.3

Forty-four F1 hybrids derived from crosses among eleven temperate japonica rice cultivars were grown and evaluated for traits related to cold tolerance including days to heading and spikelet fertility in the cold-water irrigated plot (17oC) and the control plot. Cold water treatment had highly significant influences on all traits measured in the parents and F1 hybrids. Significant positive correlation (r=0.58**) was observed between culm length and spikelet fertility in the cold water plot whereas poor correlation (r=0.25) was detected between spikelet fertility and culm length in the control. This finding indicates that spikelet fertility is affected by culm length and the cold water depth in the cold-water irrigated plot. The amount of heterosis showed variation from trait to trait. Fertility showed the highest heterosis among the five traits in the cold-water irrigated plot. In contrast, all the traits except for panicles per plant displayed negligible heterosis in the control plot. Sizes of heterosis under both field conditions were compared. In the cold- water irrigated plot midparent and better parent heterosis for spikelet fertility and heading date and midparent heterosis for culm length were significantly higher than those in the control. For panicles per plant, in contrast, midparent and better parent heterosis were significantly higher in the control than that in the cold-water irrigated plot. Our observation that heterosis can be expressed under low temperature conditions supports the idea that japonica hybrids can be grown in low temperature-prone areas where the limited growing period due to low temperature poses a ceiling on the cultivation of productive, cold-susceptible and medium-to late maturing japonica cultivars.

저온 충격에 노출된 참돔 Pagrus major 치어의 임계 저 수온 및 행동 내성 반응

윤성진(Sung Jin Yoon) 한국산학기술학회 2021 한국산학기술학회논문지 Vol.22 No.1

본 연구는 연속행동모니터링시스템(CBMS)을 사용하여 저온 충격에 노출된 참돔 Pagrus major 치어의 행동반응에 대한 임계 수온 및 행동 내성 반응을 규명하였다. 실험생물의 행동은 8.0~20.0℃ 수온구간에서 12시간과 24시간 마다 각각 2.0℃와 4.0℃씩 하강시키며 관찰하였다. 참돔 치어는 12.0℃ 이하로 수온이 하강한 경우 수온노출시간과 변동 폭에 관계없이 유영활동이 감소하고 정지가 반복되는 불안정한 행동패턴이 관찰되었다. 또한 8.0~10.0℃ 수온에 노출된 생물의 유영능력은 급격히 저하되어 수조 바닥에서 머무르는 아치사 반응 행동을 보였다. 실험어류는 저 수온 스트레스 영향을 받아 생물의 50 %만 생존하였으며, 저온 충격(cold shock) 후 6시간 이내에 모든 개체가 사망하였다. 또한 행동지수(BI)는 급격히 감소하였으며 변이계수(CV)의 진폭변화는 타 수온보다 변동 폭이 큰 것으로 분석되었다(p <0.05). 참돔 치어의 저온 스트레스는 12.0℃를 경계로 촉진되며, 8.0~10.0℃의 저온 충격에 노출된 생물의 아치사 반응을 유발시키는 내성한계인 것으로 해석된다. The critical low temperature and response of the behavioral tolerance of red sea bream Pagrus major fingerlings were determined using the continuous behavior monitoring system (CBMS). The behavior of the experimental organisms was observed by decreasing the water temperature by 2.0℃ and 4.0℃ every 12 hours and 24 hours in the range of 8.0-20.0℃. An unstable behavior pattern was observed in red seabream fingerlings exposed to water temperatures below 12.0℃, in which the swimming activity decreased and repeatedly stopped, regardless of the exposure time and water temperature fluctuation. The swimming ability of the organisms exposed to 8.0-10.0℃ decreased sharply, and the behavior of staying at the bottom of the test tank was observed. Only 50 % of the organisms survived due to the low-temperature stress, and all individuals died within six hours after the cold shock. In addition, the behavior index (BI) decreased rapidly, and the amplitude change of the coefficient of variation (CV) was found to have a greater variation than the other water temperatures (p<0.05). Low-temperature stress of red sea bream is promoted at 12.0℃, and it is interpreted as the tolerance limit, which can induce a sublethal response of the organisms exposed to cold shock of 8.0-10.0℃.

QTL Analysis of Agronomic Traits and Intracellular Substances Related to Cold Tolerance in Rice (Oryza sativa L.)

박인서,박상규,김선림,송범헌,Whnzhu Jiang,조영일,고희종,조용구 한국육종학회 2004 한국육종학회지 Vol.36 No.1

Cold acclimation of plants is a highly active process resulting from the expression of a number of physiological and metabolic adaptations to low temperature. Major metabolic changes in carbohydrates, protein, nucleic acids, amino acids, and growth regulators have been documented during the acquisition of cold tolerance. Among these, water-soluble carbohydrate (WSC) and some amino acids were shown to accumulate during cold acclimation of grass species. To determine QTLs associated with agronomic traits and the intracellular substances related to cold tolerance in rice, a molecular map consisted of 106 SSR and 26 AFLP markers has been developed using a recombinant inbred population of F8 generation derived from a cross between Dasanbyeo, a Tongil type cultivar, and TR22183, a Chinese japonica variety. The total map unit was 1,275 cM with an average distance of 9.6 cM. Most of the traits examined approximately fitted in normal distribution. The number of significant QTLs (LOD??2.0) affecting each trait ranged from one to five, a total of thirty-nine QTLs were detected from 23 traits. The QTLs derived from 23 traits explained 7.4 to 26.4% of total phenotypic variance.

QTL Analysis of Agronomic Traits and Intracellular Substances Related to Cold Tolerance in Rice (Oryza sativa L.)

In Seo Park,Sang Kyu Park,Sun Lim Kim,Beom Heon Song,Wen Zhu Jiang,Young Il Cho,Hee Jong Koh,Yong Gu Cho 한국육종학회 2004 한국육종학회지 Vol.36 No.1

Cold acclimation of plants is a highly active process resulting from the expression of a number of physiological and metabolic adaptations to low temperature. Major metabolic changes in carbohydrates, protein, nucleic acids, amino acids, and growth regula

Do northern populations of Reticulitermes speratus (Kolbe) possess an additional physiological capacity to cold-acclimate that enhances cold tolerance during the winter?

BaekYong Choi,Shiji Itakura,Tsuyoshi Yoshimura 한국응용곤충학회 2016 Journal of Asia-Pacific Entomology Vol.19 No.3

We measured and compared different carbohydrates, the total lipids, and the body water content between summer- and winter-acclimatized Reticulitermes speratus (Kolbe) in three latitudinal regions to determine whether northern populations possess an additional physiological capacity to acclimate to cold temperatures. The results of supercooling points and the lower lethal temperatures of summer- and winter-acclimatized R. speratus workers revealed that these termites are adapted to cold climates by altering their carbohydrate metabolites (e.g., glucose and trehalose), and balanced their body water content and total lipids to improve their survivability by adapting the physiological strategies to tolerate inclement environment conditions.Weobserved a mean SCP of −5.1 °C for summer-acclimatized R. speratus, which is below the observed mean lower lethal temperature; their SCP slight increase to −6.9 °C with winter-acclimatized R. speratus. Within three contrasting locations, R. speratus populations in Kyoto had higher levels of carbohydrate metabolites alteration, lower supercooling points, and lower lethal temperatures. The results of this study support the null hypothesis that termite adapted the physiological strategies to tolerate cold environment. However, the geographical range of R. speratus is not necessarily dependent on only its physiological strategies. Instead, we conclude that it appears to rely on a combination of behavioral, physiological, and other competitive adaptations that ensure the survival of the whole colony under low, non-optimal temperatures. Additionally, the northern populations of R. speratus do not possess an additional physiological capacity to cold-acclimate that enhances cold tolerance during the winter.