• Proceedings of the Korean Society of Crop Science Conference
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• 1990.05a
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• pp.46-47
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• 1990

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.2
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• pp.151-156
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• 1987

Eleven F$_1$ rice hybrids were developed by using the genetic male sterile lines having the backgrounds of Korean variety. The average heterosis, heterobeltiosis and standard heterosis for grain yield were 15.2%, 8.7% and 17.9%, respectively. Significant heterobe1tiosis for number of grains per panicle was observed. The leaf blast reaction of the hybrids was mostly similar to that of the more resistant parent. Amylose content of the hybrids ranged from 20.5% to 22.5% and protein content from 10.4% to 11.1%. The degrees of alkali digestion value, white center or white belly, clearance and heading date of the hybrids were almost same as their parents.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.4
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• pp.431-435
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• 1985

Nine hybrid rices crossed between Korean cytoplasmic-genetic male sterile rices having the WA cytoplasm and the Korean restorer lines or varieties, HR1619A/Nampungbyeo, HR1619A/Gayabyeo, HR1619A/Line234, TongilA/Nampungbyeo, TongilA/Cheongcheongbyeo, Suwon 296A/Line 209, Suwon 296A/Line 237, Suwon 296A/Line 252 and Line 201A/Line 234, and their parents were grown at Yeungnam University in 1984. The rough rice yield of the hybrids Line 201A/Line 234, TongilA/Nampungbyeo and HR1619A/Nampungbyeo were 939, 927 and 900 Kg/10a respectively. The heterosis(F$_1$/Midparent) of the above three hybrids was 40%, 20% and 19%, the heterobeltiosis(F$_1$/Better parent) was 36%, 17% and 10%, and the standard heterosis (F$_1$/Standard variety, Cheongcheongbyeo) was 19%, 17% and 14% respectively. The hybrids HR1619A/ Gayabyeo and Suwon 296A/Line 237 showed negative heterosis in grain yield. Significant heterobeltiosis for grain number per panicle was found while less or no heterobeltiosis was observed in panicle number per hill, 1000-grain weight and grain fertility. The bacterial leaf blight disease reaction of the hybrids tested was almost the same as that of one parent at least. The amylose content of the hybrids was medium to low the same as their parents. The protein content and alkali digestion value of the hybrids were almost the same as their parents.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.5
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• pp.347-351
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• 2000

Rye has been a major winter forage crop in Korea. Varietal improvement of rye has been practiced either by hybrid or population breeding systems. Hybrid breeding offers important advantages over population breeding since it is normally a cross-pollinated crop. The hybrid breeding in rye has been possible since cytoplasmically inherited forms of male sterility (CMS) and corresponding nuclear restorer genes were found. The objectives of this research were to develop the maintainer and restorer lines of Korean inbred lines and to estimate the effect of 'Pampa' type of CMS cytoplasm on yield and its related characteristics. For easy discrimination of male-sterile status of plants, anther scoring and the restore index system in which seed-setting and pollen quantity of viability were taken into account were established. High significant correlation between pollen quantity and pollen viability was found. For "Pampa" cytoplasm, four of 14 Korean inbred lines tested turned out to be a maintainer but no restorer was found. But for "235b" CMS cytoplasm, seven inbred lines acted as complete restorers. The Korean inbred rye lines acted mainly as maintainers in "Pampa" cytoplasm but acted mainly as restorer in "235b" cytoplasm. The 'Pampa' cytoplasm inducing male sterility reduced cohn length and plant height and increased the number of tiller, so forage yield and grain yield were enhanced. However, heading date was slightly delayed compared to the normal cytoplasm.elayed compared to the normal cytoplasm.

• Journal of Crop Science and Biotechnology
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• v.10 no.2
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• pp.86-91
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• 2007

A representative group of 38 improved basmati lines including maintainers of sterile lines were studied for genetic diversity utilizing Mahalanobis $D^2$ statistics. A wide diversity was observed having ten clusters with high intra- and inter-cluster distance. Heterosis was estimated utilizing the cytoplasmic male sterile lines from the clusters having high intra- and inter-cluster distance. Highly heterotic hybrids were obtained from the hybridization programme. Cross combinations IR68281A/Pusa 1235-95-73-1-1, IR68281A/RP 3644-41-9-5, Pusa 3A/UPR 2268-4-1, IR 68281A/Pusa Basmati-1, IR68281A/BTCE 10-98, and IR58025A/HKR 97-401 were found to be highly heterotic for grain yield/plant with other agronomic and quality traits. Additionally, a positive association of intra-cluster distance with heterosis was observed, which could be utilized as a guideline for predicting heterosis in basmati hybrid rice breeding program. Also, a positive association between inter-cluster distance and heterosis was observed.

• Horticultural Science & Technology
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• v.33 no.4
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• pp.550-558
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• 2015

To analyze the linkage relationships among molecular markers recently reported to be linked to onion (Allium cepa L.) Ms, a restorer-of-fertility locus, in onion (Allium cepa L.), three single nucleotide polymorphism markers were converted into cleaved amplified polymorphic sequence (CAPS) markers based on onion transcriptome sequences and the rice genome database. Analysis of the recombinants selected from 4,273 segregating plants using CAPS and other linked markers demonstrated the jnurf13 and jnurf610 markers to perfectly co-segregate with the Ms locus. In contrast to jnurf13, the jnurf610 marker was not in perfect linkage disequilibrium with the Ms locus in diverse breeding lines. Thus, the jnurf13 marker and the marker for identification of cytoplasm types were utilized to enhance the efficiency of onion breeding through four applications. First, 89 maintainer lines containing the normal cytoplasm and homozygous recessive Ms genotypes were successfully identified from 100 breeding lines. Second, these two molecular markers were used to analyze the main sources of male-fertile contaminants frequently found in the male-sterile parental lines during F1 hybrid seed production. The majority of the contaminants contained heterozygous Ms genotypes, indicating that pollen grains harboring the dominant Ms genotype may have been introduced during propagation of the maintainer lines. Therefore, the genetic purity of the two maintainer lines was analyzed in the third application, and the results showed that both maintainer lines contained 13-21% off-types. Finally, the two markers were used to increase the seed yield potentials of two open-pollinated varieties containing sterile cytoplasms by removing the plants harboring homozygous recessive and heterozygous Ms genotypes.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.3
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• pp.227-231
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• 1984

Chinese CGMS (Cytoplasmic-Genetic Male Sterility) is being transfered to Korean cultivars which will be used as CGMS maintainers. These maintainer lines along with the Chinese CGMS lines and their maintainer lines were crossed with another group of Korean cultivars which will be used as the fertility restorers, and their yield heterosis were examined. The yield heterosis was calculated as high as 113.0-221.1 % in terms of heterosis (F$_1$/Midparent) with the grand mean of 150.5%, and, 86.1-179.8% in terms of heterobeltiosis (F$_1$/better parent) with the grand mean of 125.3%. Among the female parent groups, Chinese mainteiners were the highest following by Chinese MS lines and the Korean maintainers were the lowest. Heterobeltiosis of yield components were 92.7%, 120.0%, 103.0% and 112.0% for number of panicles/unit area, number of grains/panicle, fertility per cent and 1000 grain weight, respectively. Path-coefficients of yield components to the yield were calculated. The highest one was number of grains per panicle ranging 0.8073-0.8649 followed by the 1000 grain weight ranging 0.2000-0.5032. The grain yield ratios to the grand mean were calculated in terms of combining ability. It was highest with the Chinese maintainers followed by Chinese MS lines and The Korean maintainers were lowest. This facts bring cautions to the breeding efforts to transfer the Chinese CGMS in to Korean maintainers.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.4
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• pp.73-80
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• 1980

To facilitate the heterosis breeding which utilizes cytoplasmic-genetic male sterile lines in rape (Brassica napus L.), 511 improved domestic lines were tested for their fertility restoration, maintaining ability and heterosis expression in agronomic characters. About 81 % of 511 lines showed complete fertility restoration and 11 lines could be used as maintainer of male sterility. All yield components except pod length showed greater heterotic effects than that of midparent in $F_1$. These heterotic effects resulted in extraordinary yielding ability as high as 5.6 T/ha in several $F_1$`s.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.1
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• pp.103-114
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• 1994

Pearl millet is a $C_4$ plant and summer crop originated from west Africa, and the sixth most important cereal in the world and the most widely cultivated millet in the semi-arid tropics as a major staple food crop. Its grain of higher quality protein is used to make unleavened bread chapatis and prepared as gruel, dumplings, couscous and beer. It is also used as animal feed and forage in both temperate and tropical regions because it has a capability to grow well not only in the fertile soil, but also in the poor and dry soil. Most of the current breeding procedures used in pearl millet are aimed at maximum exploitation of hybrid vigor for both grain and forage yields in Korea. Pearl millet is ideally suited for exploitation of heterosis using cytoplasmic male sterile lines as seed parent, and fertile inbred lines and open-pollinated cultivars as pollen parent. Pearl millet hybrids developed in Korea produced 3 to 7 tons of grain and 100 to 150 tons of green fodder per hectare.

• Molecules and Cells
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• v.25 no.1
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• pp.20-29
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• 2008

Cytoplasmic male sterility (CMS), one of the most important traits in crop breeding, has been used for commercial seed production by $F_1$ hybrid cultivars of pepper (Capsicum annuum L.). To develop reliable molecular markers for allelic selection of the Restorer-of-fertility (Rf) gene, which is known to be a major determinant of pollen fertility restoration in peppers, a sequence of approximately 10 kb flanking an RAPD fragment closely linked to the Rf locus was obtained by genome walking. A homology search revealed that this sequence contained an LTR retrotransposon and a non-LTR LINE-like retrotransposon. Sequencing of this Rf-linked region to search for polymorphisms between a dominant and recessive allele revealed 98% nucleotide sequence identity between them. A third polymorphic haplotype of the Rf-linked sequence, which has 94-96% nucleotide sequence identity with the two previously isolated haplotypes, was identified among a large number of breeding lines. Utilizing polymorphic sequences in the haplotypes, PCR markers were developed for selection of particular haplotypes and used to examine the distribution of the haplotypes in diverse breeding lines, cultivars, and C. annuum germplasms. Surprisingly, the third haplotype was the predominant type in C. annuum germplasms, while its frequency in $F_1$ hybrid cultivars was relatively low. Meanwhile, analysis of breeding lines whose Rf allele genotypes and male-sterility phenotypes were already known revealed that the third haplotype was mainly present in exotic breeding lines that cause unstable male-sterility when combined with sterile cytoplasms.