• 한국자원식물학회지
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• 제30권6호
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• pp.612-617
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• 2017

The preservation of pear germplasm, like that of other clonal germplasms, is difficult because it requires conservation of whole plants or their tissues. Among the currently available methods for long-term conservation of clonal germplasm, cryopreservation of shoot tips is the most reliable and cost- and space-effective option. Alginate-coated axillary shoot tips from in vitro-grown pear were conserved successfully in liquid nitrogen (LN) following dehydration. Shoot recovery from cryopreserved shoot tips was improved greatly after 8 weeks of cold acclimation, but recovery decreased slightly after then. The highest regeneration rate was observed when in vitro shoot tips were preincubated in MS (Murashige and Skoog) medium with 0.3 M sucrose for 48 h, and when alginate-coated shoot tips were precultured in MS medium with increasing sucrose concentrations (0.5 M and 0.7 M) for 8 and 16 h, respectively. When the encapsulated beads were dehydrated for up to 7 h [25% water content (fresh weight basis)] under laminar flow, the highest regeneration rate was observed in "BaeYun No. 3" (55.7%) and "Whanggeum" (43.3%) after warming from LN. This technique is useful as a practical procedure to cryopreserve plant material that is sensitive to freezing of the surrounding cryoprotectant medium. Therefore, this technique appears to be promising for the cryopreservation of shoot tips from in vitro-grown plantlets of pear germplasm.

• 한국자원식물학회지
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• 제25권6호
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• pp.762-772
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• 2012

The objective of this study was to analyze the genetic diversity using SSR marker and investigate the fatty acid composition of perilla (P. frutescens var. frutescens) germplasm. Genetic diversity among 95 accessions, which consisted of 29 weedy types and 66 landrace accessions, was evaluated based on 12 SSR markers carrying 91 alleles. The mean values of observed ($H_O$) and expected heterozygosities ($H_E$) were 0.574 and 0.640, respectively, indicating a considerable amount of polymorphism within this collection. A genetic distance-based phylogeny grouped into two distinct groups, which were the landrace, moderate and weedy type, genetic distance (GD) value was 0.609. The physicochemical traits about crude oil contents and fatty acid compositions were analyzed using GC. Among tested germplasm, the total average oil contents (%) showed a range from 28.57 to 49.67 %. Five fatty acids and their contents in the crude oils are as follows: ${\alpha}$-linolenic acid (41.12%-51.81%), linoleic acid (15.38%-16.43%), oleic acid (18.93%-27.28%), stearic acid (2.56%-4.01%), and palmitic acid (7.38%-10.77%). The average oil content of wild types was lower than landrace, and the oil content of middle genotype accessions was higher than other germplasm, but no significant variation between landrace and wild types was shown. Nevertheless, IT117174, landrace of Korea, was highest in crude oil content (47.11%) and linolenic acid composition (64.58%) among the used germplasm. These traits of the selected accessions will be helped for new functional plant breeding in perilla crop.

• Asian-Australasian Journal of Animal Sciences
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• 제18권10호
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• pp.1387-1402
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• 2005

Indian subcontinent is a rich source of diverse ovine germplasm, and only very few countries have such a large number of breeds with wide genetic diversity. This vast ovine biodiversity in India is being eroded rapidly and more than 50% of sheep breeds are currently under threat. It is noteworthy that the characterization of Indian sheep breeds was last done in the first half of the century since then no recent estimates are available and surveys in majority of the regions/breeds are far from complete. Starting in 1985 National Bureau of Animal Genetic Resources (NBAGR), Karnal, India, therefore, initiated activities aimed at determining the status and compiling information on indigenous farm animals including sheep. This report represents attempts made to date on the basis of field/literature surveys and additional activities on molecular characterization to ascertain their status including distribution, population changes, breed diversities and risk status. The need, mode and mechanisms of conservation are also described. Involvement of several agencies for evaluation, improvement, conservation programmes and recommendations made for effective characterization and conservation of sheep biodiversity are highlighted. This publication would promote action particularly at national level to improve the information base on domestic Indian breeds of sheep and provide input into national domestic sheep diversity conservation policy decisions.

• 한국작물학회지
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• 제49권4호
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• pp.354-357
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• 2004

A simplified technique which cryoprotects zygotic embryos by encapsulation-dehydration was developed for the germplasm conservation of herbaceous peony (Paeonia lactiflora Pall.). The highest survival rate $(85\%)$ was obtained from embryos treated by encapsulation-dehydration. The zygotic embryos were precultured on MS medium containing 0.3mg/L $GA_3$ for 1 day. The precultured embryos were encapsulated in $3\%$ (w/v) alginate beads and immersed for 1 h in MS medium containing 2 M glycerol and 0.5 M sucrose. The encapsulated embryos were dehydrated for 5h by air drying prior to direct immersion in liquid nitrogen. This encapsulation-dehydration method appears to be a promising technique for germplasm cryopreservation of a herbaceous peony.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.82-82
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• 2017

The production of spring wheat, the major crop in Mongolia, is accounting for 98% of the cultivated area. Collection, conservation and utilization of wheat germplasm resources play an important role in wheat breeding and production in Mongolia. Understanding genetic variability in the existing genebank accessions is important for collection and conservation of wheat germplasms. To determine the genetic diversity and population structure among a representative collection of Mongolian local wheat cultivars and lines, 200 wheat accessions were analyzed with 15 SSR markers distributed throughout the wheat genome. A total of 85 alleles were detected, with 3 to 5 alleles per locus and a mean genetic diversity value of 5.66. The average genetic diversity index was 0.68, with values ranging from 0.37 to 0.80. The 200 Mongolian wheat accessions were divided into two subgroups based on STRUCTURE, un-rooted NJ cluster and principal coordinate analyses. The results from this study will provide important information for future wheat germplasm conservation and improvement programs with Mongolian genebank.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2021년도 춘계학술대회
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• pp.38-38
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• 2021

The seeds of rice with variable status were examined the germination rate after 10 years of long-term storage (-18℃) conservation. For seeds of wild relatives, 2 accessions were examined and germination rate of all accessions showed no changed after freezing conservation. For seeds of native germplasm, 1,259 accessions were examined and germination rate of 696 accessions was increased or showed no change after 10 years of long-term storage. Germination rate of 432 accessions was decreased with below 15% of initial germination rate. For 79 accessions of native germplasm, germination rate of seeds was decreased with above 15% of initial germination rate after 10 years of long-term storage, which is needed to be rejuvenated. For seeds of developed varieties, 873 accessions were examined and germination rate of 486 accessions of developed varieties was increased or showed no change after 10 years of long-term storage. Germination rate of 251 accessions was decreased with below 15% of initial germination rate. For 25 accessions of developed varieties, germination rate of seeds was decreased with above 15% of initial germination rate after 10 years of long-term storage, which is needed to be rejuvenated. For seeds of developed line, 2,131 accessions were examined and germination rate of 1,245 accessions of developed line was increased or showed no change after 10 years of long-term storage. Germination rate of 588 accessions was decreased with below 15% of initial germination rate. For 96 accessions, germination rate of seeds was decreased with above 15% of initial germination rate, which is needed to be rejuvenated.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 추계학술대회
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• pp.43-43
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• 2019

The collection, evaluation and conservation of crop germplasm have been treated as one of the basics to breeding program. An understanding of genetic relationships among germplasm resources is vital for future breeding process like yield, quality, and resistance. In the present study, EST-SSR markers were employed to assess the polymorphism and genetic diversity of 192 accessions of Proso millet preserved in the National Agrobiodiversity Center of RDA. We evaluated the efficiency of EST-SSR markers developed for proso millet species. A total of 98 alleles were detected with an average allele number of 4.5 per locus among 192 proso millet millet accessions using 22 EST-SSR markers. The averaged values of gene diversity ($H_E$) and polymorphism information content (PIC) for each EST-SSR marker were 0.362 and 0.404 within populations, respectively. Our results showed the moderate level of the molecular diversity among the proso millet accessions from diverse countries. A phylogenetic tree revealed three major groups of accessions that did not correspond with geographical distribution patterns with a few exceptions. The less correlation between the clusters and their geographic location might be considered due to their type difference. Our study provided a better understanding of genetic relationships among various germplasm collections, and it could contribute to more efficient utilization of valuable genetic resources. The EST-SSR markers developed here will serve as a valuable resource for genetic studies, like linkage mapping, diversity analysis, quantitative trait locus/association mapping, and molecular breeding.

• 한국자원식물학회지
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• 제36권6호
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• pp.562-570
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• 2023

The droplet-vitrification technique for cryopreservation has proven successful across a diverse range of germplasm, ensuring safe and effective long term preservation. In this study, we investigate an effective cryopreservation protocol using the droplet-vitrification technique for shoot tips of Freesia hybrida cultivars 'Sunny Gold' and 'Sweet Lemon'. To determine optimal conditions for Freesia cryopreservation, we employed a carefully selected standard procedure along with additional treatments and alternative solutions. For 'Sunny Gold', the highest regrowth rate of 24% was achieved when shoot tips underwent dehydration with PVS3 solution for 120 minutes before direct immersion in liquid nitrogen (LN) for 1 hour, coupled with a standard protocol involving a two-step preculture with 0.3 M - 0.5 M sucrose, loading with C4 for 40 minutes, and unloading with 0.8 M sucrose for 40 minutes. In the case of 'Sweet Lemon,' regrowth of cryopreserved shoot tips was observed with dehydration treatments, including PVS2 (A3) for 60 minutes and PVS3 (B1) for 60 minutes, as well as longer exposure. The results reflect the distinct sensitivity of shoot tips to chemical toxicity and osmotic stress in these two genotypes. This study provides valuable evidence to consistently enhance the effectiveness of cryopreservation methods for the long-term conservation of Freesia germplasm.

• 한국작물학회지
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• 제63권1호
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• pp.1-7
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• 2018

Information on the patterns of genetic diversity and population structure is essential for the rational use and efficient management of germplasms; accurate information aids in monitoring germplasms, and can also be used to predict potential genetic gains. In this study, we assessed genetic diversity, focusing on Korean rice accessions for theand their sustainable conserved diversity. Using DNA profiling with 12 simple sequence repeat (SSR) markers, we detected a total of 333 alleles among 2,016 accessions. The number of alleles ranged from 21 to 53, with an average of 27.8. Average polymorphism information content was 0.797, with the lowest being 0.667 and the highest 0.940. CA cluster analysis and the model-based population structure revealed two main groups that could be subdivided into five subgroups. Analysis of the molecular variance study based on the SSR profile data showed 5% variance among the profiles, whereas we recorded 93% variance among individuals and 2% variance within individuals. Specifically, the utilized diversity for of the breeding program is restricted in that cultivars were located in limited clades. These results revealed that preserving the diversity of Korean landraces could be useful sources for breeding new rice cultivars, and cwould be the basis for the sustainable conservation and utilization of a Korean rice germplasm.

• 한국작물학회지
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• 제60권1호
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• pp.75-84
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• 2015

Sesame (Sesamum indicum L.) is one of the most important oilseed crops with high oil contents and rich nutrient value. The development of a core collection could facilitate easier access to sesame genetic resources for their use in crop improvement programs and simplify the genebank management. The present study was initiated to the development and evaluation of a core collection of sesame based on 5 qualitative and 10 quantitative trait descriptors on 2,751 sesame accessions. The accessions were different countries of origin. About 10.1 percent of accessions were selected by using the power core program to constitute a core collection consisting of 278 accessions. Mean comparisons using t-test, Nei's diversity index of 10 morphological descriptors and correlation coefficients among traits indicated that the existing genetic variation for these traits in the entire collection has been preserved in the core collection. The results from this study will provide effective information for future germplasm conservation and improvement programs in sesame.