• Journal of Crop Science and Biotechnology
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• v.10 no.2
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• pp.106-111
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• 2007

Increasing genetic variability with mutagenic agents has been broadly employed in plant breeding because it has the potential to alter one or more desirable traits. In this study, a molecular analysis assessed by Amplified Fragment Length Polymorphisms(AFLPs) and a morphological analysis based on seedlings subjected to aluminum stress were compared. Also, an analysis of allelic frequencies was performed to observe unique alleles present in the pool. Genetic distances ranging from 0.448 to 0.953 were observed, suggesting that mutation inducing was effective in generating variability. The genetic distances based on morphological data ranged from 0(genotypes 22 and 23) to 30.38(genotypes 15 and 29). In the analysis of allelic frequency, 13 genotypes presented unique alleles, suggesting that mutation inducing was also targeting unique sites. Mutants with good performance under aluminum stress(9, 15, 18 and 27) did not form the same clusters when morphological and molecular analyses were compared, suggesting that different genomic regions may be responsible for their better performance.

• The Plant Pathology Journal
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• v.35 no.6
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• pp.644-653
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• 2019

The genetic variability of 'Candidatus Liberibacter asiaticus' (CLas) population associated with huanglongbing (HLB) disease of citrus in North Eastern (NE) region of India, a geographically locked region, and home for the diversity of many citrus species was analyzed on the basis of tandem repeat numbers (TRN) in variable CLIBASIA_01645 genomic loci. Fifty-five CLas strains sampled from different groves of NE Hill (NEH) region of India were in single amplicon group, but there was remarkable genetic variability in TRNs. The TRN in HLB-associated CLas strains varied from 0-21 and two novel repeat motifs were also identified. Among the NE population of CLas, TRN5 and TRN9 were most frequent (total frequency of 36.36%) followed by TRN4 (14.55%) and TRN6, TNR7 with a frequency of 12.73% each. Class II type CLas genotypes (5 < TRN ≤ 10) had highest prevalence (frequency of 60.00%) in the samples characterized in present study. Class I (TRN ≤ 5) genotypes were second highest prevalent (29.09%) in the NEH region. Further analysis of genetic diversity parameters using Nei's measure (H value) indicated wide genetic diversity in the CLas strains of NE India (H value of 0.58-0.86). Manipur CLas strains had highest genetic variability (0.86) as compared to Eastern, Southern and Central India. The R₁₀ values (TRN ≤ 10/TRN > 10) of NE CLas population was 10.43 (73/7), higher from other regions of India. Present study conclusively reported the occurrence of high genetic variability in TRN of CLas population in North East Indian citrus groves which have evolved to adapt to the specific ecological niche.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.6
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• pp.755-761
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• 2005

Blood samples were collected from eight native Japanese breeds of chickens (Miyadi-dori, Ohiki, Onaga-dori, Shoukoku, Tosa-Jidori, Tosa-Kukin, Toutenkou and Uzurao) and two foreign breeds of chickens (White Leghorn and Rhode Island Red) to examine the genetic variability and relationships among the breeds by using a microsatellite DNA technique. Except for the Shoukoku breed, the other Japanese chicken breeds all originate from Kochi Prefecture. Ohiki, Onaga-dori, Tosa-Jidori, Toutenkou and Uzurao are fancy fowl, and Miyadi-dori and Tosa-Kukin are utility fowl. Among the fancy fowl, Ohiki, Onaga-dori, and Toutenkou males have thick and long feathers in the saddle and tail. Genetic variabilities of the 20 microsatellites examined, varied depending on the breed: the mean number of alleles per locus ranged from 2.05 (Miyadi-dori) to 3.90 (Rhode Island Red); proportion of polymorphic loci ranged from 0.75 (Miyadi-dori) to 1.00 (Rhode Island Red, Shoukoku and Uzurao); and mean expected heterozygosity ranged from 0.330 (Miyadi-dori) to 0.607 (Rhode Island Red). Unique microsatellite alleles were detected in each breed. Using the neighbour-joining method, phylogenetic trees were constructed based on the genetic distances of D$_{A}$ and D$_{ST}$. Among the breeds originating from Kochi Prefecture, fancy and utility breeds belonged to different clusters. Among the fancy breeds, those having thick and long feathers in the tail and saddle showed a close genetic relationship to the Shoukoku breed, which also has thick and long feathers in the tail and saddle.

• The Korean Journal of Malacology
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• v.15 no.1
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• pp.13-20
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• 1999

A horizontal starch gel electrophoresis for enzyme proteins extracted from three Korean species and one Chinese species of Semisulcospira was carried out in order to elucidate their genetic relationships. A total of 10 enzymes were employed in three different of buffer systems. Two loci from each enzyme of GAPDH, GOT, ICDH, IDH and PEP(VL); three loci from each of three enzymes, EST, PEP(LGG) and PGDH; and five loci from GPI were observed. Most of the loci in three pleurocerid species employed showed homozygous monomorphic banding patterns and some of them were specific as genetic markers between two different species. However, EST-2, PEP(LGG-3) and PGDH-1 loci in Korean S. libertina and PEP(LGG-3), PGM-1 and PGM-2 loci in Chinese S. libertina showed polymorphic banding patterns. Three Korean Semisulcospira species including S. libertina were more closely clustered in a dendrogram within the range of genetic identity values of 0.818-0.936, and these clusters were lineated with Chinese S. libertina at the value of 0.621.

• Journal of Life Science
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• v.25 no.12
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• pp.1347-1353
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• 2015

The fleshy shrimp, Fenneropenaeus chinensis, is the family of Penaeidae and one of the most economically important marine culture species in Korea. However, its genetic characteristics have never been studied. In this study, a total of 240 wild F. chinensis individuals were collected from four locations as follows: Narodo (NRD, n = 60), Beopseongpo (BSP, n = 60), Chaesukpo (CSP, n = 60), and Cheonsuman (CSM, n = 60). Genetic variability and the relationships among four wild F. chinensis populations were analyzed using 13 newly developed microsatellite loci. Relatively high levels of genetic variability (mean allelic richness = 16.87; mean heterozygosity = 0.845) were found among localities. Among the 52 population loci, 13 showed significant deviation from the Hardy–Weinberg equilibrium. Neighbor-joining, principal coordinate, and molecular variance analyses revealed the presence of three subpopulations (NRD, CSM, BSP and CSP), which was consistent with clustering based on genetic distance. The mean observed heterozygosity values of the NRD, CSM, BSP, and CSP populations were 0.724, 0.821, 0.814, and 0.785 over all loci, respectively. These genetic variability and differentiation results of the four wild populations can be applied for future genetic improvement using selective breeding and to design suitable management guidelines for Korean F. chinensis culture.

• Korean Journal of Plant Resources
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• v.11 no.3
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• pp.264-271
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• 1998

This study was conducted to investigate morphological characteristics of Korean local garlic varieties and to define the genetic variability and the correlations amongthe characters associated with yield. The plant height, the leaf sheath diameter, the nubmer of leaves, and bulb weight were significantly increased in the garlic plants from heavier seed bulbs. The proportation of six clove bulbs was more than 60% in Seosan variety and this was not realted with the number of cloves in seed bulb. While more than 70% bulbs in Jeoksung and Danyang varieties cultivated in paddy field were composed of 6 or 7 cloves, majority of the bulbs of Euisung and Danyang varieties cultivated in upland were composed of bulbs with 7 cloves or more. The highest genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) were observed in bulb weight. GCV and PCV also showed high value in leaf sheath diameter. Thus, there is a greater scope for selection of these characters. The small difference between PCV and GCV values in plant height indicates that the environmental influence would be limited in this character. High heritability was observed of plant height (56.76%) and bulb weight (45.95%). And the weight per bulb (34.24%) exhibited highest genitic advance followed by leaf sheath diameter (18.8%) and plant height (9.61%), and those would be the ideal characters for selelction.

• The Plant Pathology Journal
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• v.34 no.2
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• pp.93-103
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• 2018

Leaf blotch of wheat caused by Bipolaris sorokiniana is a major constraint to wheat production, causing significant yield reduction resulting in severe economic impact. The present study characterizes to determine and compare pathogenic variability exist/not based on components of leaf blotch disease development and level of aggressiveness due to agroclimatic condition of B. sorokiniana in wheat. A total of 169 virulent isolates of B. sorokiniana isolated from spot blotch infected leaf from different wheat growing agroclimate of Bangladesh. Pathogenic variability was investigated on a susceptible wheat variety 'kanchan' now in Bangladesh. A clear evidence of positive relationship among the components was recorded. From hierarchical cluster analysis five groups were originating among the isolates. It resolved that a large amount of pathogenic diversity exists in Bipolaris sorokiniana. Variation in aggressiveness was found among the isolates from different wheat growing areas. Most virulent isolates BS 24 and BS 33 belonging to High Ganges River Flood Plain agro-climatic zones considered by rice-wheat cropping pattern, hot and humid weather, high land and low organic matter content in soil. Positive relationship was found between pathogenic variability and aggressiveness with agro-climatic condition.

• Journal of Crop Science and Biotechnology
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• v.10 no.4
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• pp.211-222
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• 2007

Selection of the appropriate parents to be used in artificial crosses is one of the main decisions faced by plant breeders that will facilitate the exploitation of maximum genetic variability and production of superior recombinant genotypes. Several techniques have been used in aiding the identification of genotypes with promising and desirable agronomical traits for hybridization. In this way, the objective of the present review is to gather available information for the selection of parents based on different breeding designs and analytical tools showing their similarities and highlighting the main advantages and disadvantages of their use.

• Proceedings of the Botanical Society of Korea Conference
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• 1987.07a
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• pp.9-18
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• 1987

The plant breeding, a discipline of agricultural sciences, has greatly contributed to huan welfare in relieving food crisis by development of higher yielding, stronger resistant and better quality varieties. However, many conventional plant breeders, especially ones working for major crops, are facing exhaustion of useful genetic variability, which greatly limit the potentional of developing better cultivars. Therefore, the convectional plant breeders have been eagerly looking for new renovational methods in creating genetic varibility. It has been expected that biotechnology would provide the technique to create totally new genetic variability through gene transfer, chromosome manipulation and/or cell fusion. It is strongly suggested that very close interdisciplinary approaches between convectionla plant breeders and biotechnoligists is essentional for opening new era in developing better varieties.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.10
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• pp.1369-1378
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• 2006

This is the first study in which genetic variability and relationships of a large number of Japanese chicken breeds were revealed along with those of several foreign breeds by using microsatellite DNA polymorphisms. Twenty-eight breeds (34 populations) of native Japanese chickens and seven foreign breeds or varieties were analyzed. The mean number of alleles per locus, the proportion of the polymorphic loci, and the expected average heterozygosity ranged from 1.75 to 4.70, from 0.55 to 1.00, and from 0.21 to 0.67, respectively. Microsatellite alleles being unique to a particular population were detected in some populations. The $D_A$ genetic distance between populations was obtained from allele frequency for every pair of the populations to construct a neighbor-joining tree. According to the phylogenetic tree, excluding a few exceptions, native Japanese chicken breeds and foreign breeds were clearly separated from each other. Furthermore, the tree topology divided native Japanese chickens into four main classes, which was almost in accordance with the classification based on body morphology; that is, (1) Cochin type, (2) Malay type, (3) layer type, and (4) intermediate type between Malay and layer types. This is the first finding for native Japanese chickens.