• Journal of Practical Agriculture & Fisheries Research
• /
• v.3 no.1
• /
• pp.85-93
• /
• 2001

The inter-relationship and combining abilities of characters for leaf length, leaf width, branch number, leaf number, leaf area, fresh weight and dry weight were studied in the F₁ combination of 15 crosses from the partial six-parent diallel cross in Petunia hybrida. The leaf area, fresh weight and dry weight showed high positive correlation together with the other growth characters such as leaf length, leaf width, branch number, leaf number. The mean squares of general combining ability(GCA) and specific combining ability(SCA) were highly significant for all the growth characters. The estimates of variance components of SCA were greater than those of GCA for all the characters, showing preponderance of non-additive gene actions for these characters. GCA effect was high in the lines of D and G for leaf length and fresh weight, and in the lines of C and D for branch number, leaf number, leaf area and fresh weight. The crosses of D×E, D×G, and E×G exhibited high SCA effect for all the growth characters such as leaf length, leaf width, branch number, leaf number, leaf area, fresh weight, and dry weight. The broad sense heritability was generally high compared to narrow sense one in the 7 characters. The highest heritability of the broad and narrow sense was shown in the leaf width and dry weight.

• The Korean Journal of Mycology
• /
• v.22 no.4
• /
• pp.378-385
• /
• 1994

Interspecific somatic hybrids were obtained by protoplast fusion between Pleurotus ostreatus and Pleurotus sajor-caju. The fusion products between incompatible strains did not form clamp connections. Fruiting body of the clampless fusants was induced by light-dark cycle on saw-dust-rice bran substrate in glass bottles. Out of them, seven somatic hybrids produced fruiting bodies of intermediate morphology of the two species. Light and low temperature were the initiating factors for the development of clamped hyphae from the clampless mycelial colonies. All of these basidiocarps had clamp connections. Eight fusants from the six crosses were analysed with the segregation of genetic characters by random spore isolates. In the three combinations, unexpected alleles were shown. Somatic hybrid between P188 (P. ostreatus 2-1 + P. sajor-caju 2-53) and P. florida 2-3 by triple cross produced fruiting bodies similar to those of fusant between P. ostreatus and P. florida. All the genetic charaters from the three strains were shown to segregate and recombine.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.6 no.1
• /
• pp.45-48
• /
• 2003

We have previously cloned and characterized the complete fibroin L-chain gene from one of the silkworm races Baekok-Jam (Bombyx mori) and found two variable regions (I, intron 2 ~ exon 3; II, intron 6) with the primer sets designed to cover these variable regions. We tested the utility of these regions as genetic markers among silkworm races. For the purpose of study, Japanese race (Jam 123), Chinese race (Jam 124) and their F$_1$hybrid Baekok-Jam were used. The PCR product size of region I was 787 bp in Jam 123, 770 bp in Jam 124 and 768 bp in Baekok-Jam. The size of region II was 470 bp in Jam 123, 428 bp in Jam 124 and 429 Up in Baekok-Jam. In the extended experiment, Jam 125 (Japanese race), Jam 126 (Chinese race) and their F$_1$hybrid Daeseong-Jam were also analyzed. The sizes of region I and II in Jam 125, Jam 126 and Daeseong-Jam were similar to those of Jam 123, Jam 124 and Baekok-Jam. DNA sequence divergence between the two geographic races of Jam 123 or Jam 125 and Jam 124 or Jam 126 was substantial. The result suggests that the fibroin L-chain gene of F$_1$hybrids were inherited from Chinese races. These results are concordant with cocoon shapes of tested animals, and suggested that Baekok-Jam or Daeseong-jam is more closely related to Jam 124 or Jam 126 than to Jam 123 or Jam 125. Taken these data together, the primer sets designed from two variable regions of fibroin L-chain gene would be highly useful, as the genetic markers for silkworm races, at least in Japanese and Chinese races, although an extended study including more geographic races is required.

• Korean Journal of Weed Science
• /
• v.10 no.3
• /
• pp.179-185
• /
• 1990

Five parents which showed differential response to thiobencarb and their $F_1$ hybrids were treated with thiobencarb (S-[(4-chlorophenyl) methyl]diethylcarbamothioate) at 2 and 4 kg ai/ha in order to investigate the inheritance of rice (Oryza sativa L.) to the herbicide. In the analysis of diallel crosses for tolerance of rice cultivars to the herbicide, highly significant GCA (general combining ability) and SCA (specific combining ability) effects were observed at both herbicide rates using the parameters of plant height and dry weight ; the GCA effect being greater than the SCA effect. The additive effects appeared to be more prevalent than dominance effects, and partial dominance was recognized in relation to herbicide tolerance in the different rice cultivars. Higher heritabilities in the narrow and broad senses were observed at 4 kg ai/ha. The heritabilities in the narrow sense for plant height and dry weight were 0.726 and 0. 743, respectively. IR9660-50-3-1 which showed the highest GCA effects seemed to possess more dominant genes related to herbicide tolerance than the other rice cultivars tested.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.12 no.1
• /
• pp.29-34
• /
• 2006

A breeding programme was initiated during 2001 utilizing two polyvoltine silkworm breeds viz. $BL_{69}$, an evolved breed tolerant to high temperature and MAR, comparatively resistant to Bombyx mori nuclear polyhedrosis virus (BmNPV) with the objective to develop robust polyvoltine breeds and hybrids. The breed $NP_1$ was developed by exposing the fifth instar larvae to high temperature $(36{\pm}1^{\circ}C)$, high Relative Humidity ($85{\pm}5%$ R.H.) and inoculating third instar larvae with BmNPV inoculum. At $F_{12}$, the breed was tested for hybrid forming ability utilizing six bivoltine silkworm breeds viz. $CSR_2,\;CSR_4,\;CSR_{17},\;CSR_{18},\;CSR_{19}\;and\;NB_4D_2$. The hybrid $'NP_1{\times}CSR_{17}'$ exhibited its superiority by recording 97.2% survival, 1.892 g cocoon weight, 0.406 g cocoon shell weight, 21.5% cocoon shell ratio, 16.6% raw silk percentage and 890 m filament length whereas the control $(PM{\times}CSR_2)$ has recorded 90.2% survival, 1.599 g cocoon weight, 0.304 g cocoon shell weight, 18.9% cocoon shell ratio, 13.1 % raw silk percentage and 768 m filament length. Commercial exploitation of the new $polyvoltine{\times}bivoltine$ hybrid in sericulture industry has been discussed.

• Journal of Life Science
• /
• v.17 no.4 s.84
• /
• pp.493-497
• /
• 2007

The study were performed genetic analysis for seed characters of 6 parents of rice cultivar and 15 $F_1$ hybrids. In terms of heritability, The highest value was observed in the character of No. of grains/spike. Second values was showed 1,000 grains weight and head rice ratio was high value than grain length and width. In an analysis of correlation relation of parent, significant positive coefficients were observed in head rice ratio and No. of grains/spike, grain length and 1,000 grains weight, but the negative coefficients were significantly revealed between grain length and No. of grains/spike. Phenotype coefficient was lowly observed in the relation of grain length and 1,000 grains weight, grain width and 1,000 grain weight that highly positive genetic coefficient was showed in an analysis of correlation relation of $F_1$. In terms of heterosis, highest value was showed 1,000 grains weight and second value was No. of grains per spike and 1,000 grains weight and second value was No. of grains per spike in terms of heterobeltiosis. In an analysis heterosis of among crossing combination, high ratio was observed 1st combination at seed length, 12th combination at seed width, 3rd combination at head rice ratio, 5th combination at 1,000 grains weight and 11th combination at No. of grains per spike. In an analysis heterobeltiosis of among crossing combination, high ratio was observed 1st combination at seed length, 12th combination at seed width, 3rd combination at head rice ratio, th combination at 1,000 grains weight and 11th combination at No. of grains per spike.

• Journal of Sericultural and Entomological Science
• /
• v.4
• /
• pp.63-68
• /
• 1965

This treatise was carried out to study the hereditary phenomenon of silk lousiness and the interaction of genes related with silk lousiness. It was also studied how to improve the silk lousiness of general raw silk by refining process because the selective process was found as unsatisfactory method. The conclusions reached were as follows. A. Conclusions related with genetic problem. 1. The decreased effects of the lousiness were 11 % in the F$_1$ hybrids. 2. Lousiness was considered to inherit as the incomplete dominance. 3. The effects of the lousiness gene were additive, and the lousiness of raw silk might be influenced by more than two genes. 4. The quantitative characters of cocoons were not genetically correlated with the occurrence of lousiness. 5. Lousiness could not be said to occur more in the heavy-cocoon strains. 6. The microscopic lousiness test of this paper showed the same result of the international exforiation test. B. Conclusions related with lousiness improvement. 1. Raw silk was able to be refined by the employment of 0.2% cationic softener solution for 30 minutes at 95$^{\circ}C$, supressing the occurrence of lousiness. 2. Anionic chemical softener was not available for silk refining process. 3. The above cationic softener refining prosess did not cause any physical defect for the silk fiber. 4. Soap refining process caused silk lousiness easily.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.11 no.2
• /
• pp.68-75
• /
• 1991

A series of tests was carried out to determine the purity and germination of pasture plant and forage crop seeds imported in 1986 and 1987 at the grassland and forage laboratory, College of Agriculture, Seoul National University, Suweon. At the same time, the results obtained were compared with the National Livestook Cooperatives Federation(NLCF1's seed standards as a guide for determining seed quality. 1. The germination percentages of Potomac orchardgrass, Fawn tall fescue, Aquila Ky bluegrass and California ladino clover among grasses and legumes tested were lower than those of the N1,CF's standards, but the germination percentages of forage crops were higher than those of the NLCF's standards. 2. The purity of Potomac orchardgrass and Aquila Ky bluegrass were relatively lower than those of the NLCF's standards. 3. The percentages of other crop seeds in Potomac orchardgrass, Fawn tall fescue, Aquila Ky bluegrass and Cayuse oats were lower than those of the NLCF's standards. 4. Percentage of inert matter in the seeds was lower compared with the NLCF's standards except Akela ' forage rape. 5. The seeds of Potomac orchardgrass, NK 367 sorghum hybrid and sorghum x sudangrass hybrids such as NC+855, G83F and TE Haygrazer were contaminated with one or more weed seeds. Rumex spp. was by far the most common weed in the seeds imported. The other weeds occurred at a low level were Rumex acestosella, Senecio jacobaea, Cirsium arvense and Cuscicta spp. 6. There were many variations in 1,000 seed weight among different species. A thousand seed weight of Aquila Ky bluegrass was 0.263g, but that of Tetrone Italian ryegrass, Akela forage rape and Pioneer 3160 sorghum x sudangrass hybrid was 3.875, 3.476 and 242.4578, respectively. 7. According to the fluorescence test of ryegrass seed, Tetrone Italian ryegrass was known as a true annual type, but an unknown cultivar produced in Cheju was contaminated with 6% of perennial ryegrass seed.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.47 no.5
• /
• pp.361-367
• /
• 2002

In order to determine the optimum harvest time for the seed production of inbreds and hybrids in silage corn, the ears of sib-pollinated 'KS5', 'KS7rhm', and 'Ga209' and cross-pollinated 'KS5' $\times$ 'KS6' (Suwon19), 'KS7 rhm' $\times$ 'KSl17' (Suwonok), and 'Ga209' $\times$ 'DB544'(Kwanganok) were harvested at the one-week intervals from 4 to 10 weeks after silking. The optimum harvest time for the seed production for 'KS5', 'KS5' $\times$ 'KS6', 'KS7 rhm', and 'KS7rhm' $\times$ 'KS117' was 7 weeks after silking considering both emergence rate and plumule growth in cold test. Although earlier harvested seeds showed similar germination rate as the seeds harvested at the optimum time at $25^{\circ}C$, their emergence rate were lower in cold test. Seed weight and $\alpha$-amylase activity of earlier harvested seeds were lower compared to those of seeds harvested at the optimum time, while leakage of total sugars and electrolytes were higher. However, the later harvested seeds showed lower germination rates at $25^{\circ}C$ and emergence rates in cold test probably due to the lower $\alpha$-amylase activity although they showed increased seed weight and reduced leakage of total sugars and electrolytes. In contrast, the emergence rate of 'Ga209' and 'Ga209' $\times$ 'DB544' in cold test increased up to 10 weeks after silking probably due to the increased seed weight and $\alpha$-amylase activity and reduced sugar and electrolyte leakages during the germination. The cross-pollinated F$_1$ hybrid seeds showed higher germination and emergence rates at $25^{\circ}C$ and in cold test, and higher plumule growth and $\alpha$-amylase activity compared to those of sib-pollinated inbreds.

• Horticultural Science & Technology
• /
• v.30 no.1
• /
• pp.64-72
• /
• 2012

Phytophthora root rot has been causing a serious yield loss in pepper production. Since 2004, the year in which commercial cultivars resistant to the disease were firstly commercialized, it has been necessary to introduce the resistance into domestic pepper cultivars for dried red pepper. Therefore, developing molecular markers linked to the resistance is required for an accurate selection of resistant plants and increasing breeding efficiency. Until now, several markers associated with the major dominant gene resistant to Phytophthora root rot have been reported but they have some serious limitations for their usage. In this study, we aimed to develop molecular markers linked to the major dominant gene that can be used for almost of all genetic resources resistant to Phytophthora root rot. Two segregating $F_2$ populations derived from a 'Subicho' ${\times}$ 'CM334' combination and a commercial cultivar 'Dokyacheongcheong' were used to develop molecular markers associated with the resistance. After screening 1,024 AFLP primer combinations with bulked segregant analysis, three AFLP (AFLP1, AFLP2, and AFLP3) markers were identified and converted into three CAPS markers (M1-CAPS, M2-CAPS, and M3-CAPS), respectively. Among them, M3-CAPS marker was further studied in ten resistants, fourteen susceptibles, five hybrids and 53 commercial cultivars. As a result, M3-CAPS marker was more fitted to identify Phytophthora resistance than previously reported P5-SNAP and Phyto5.2-SCAR markers. The result indicated that the M3-CAPS marker will be useful for resistance breeding to Phytophthora root rot in chili pepper.