Abstract
Hyacinth, one of the five best-selling bulbous flowers in the world, is a favored flower of garden landscapes in the spring. Hyacinth has a single origin, but there are many horticultural varieties. Physical mapping of ribosomal DNA (rDNA) and telomeric repeat loci by fluorescence in situ hybridization (FISH) is helpful to understand the genetic relationship and chromosome inheritance in hyacinth breeding. In this study, 45S rDNA, 5S rDNA and telomeric repeats were used as probes, the mitotic metaphase chromosomes of 8 diploid hyacinth cultivars were analyzed by FISH location, and their karyotype parameters were analyzed by Q-type cluster analysis. The results showed that two 45S rDNA loci were detected in all eight hyacinth cultivars, four 5S rDNA loci were detected in ‘Gypsy Queen’, and three were detected in other cultivars. In addition to the presence of telomere loci at both ends of chromosomes, seven telomere loci were detected in ‘Gypsy Princess’ and ‘Yellow Stone’, and eight telomere loci were detected in other cultivars. At the same time, when the euclidean distance between groups was 20, the eight hyacinth cultivars were clustered into three groups (‘Yellow Stone’, ‘Red Pearl’ and ‘Pink Pearl’), and ‘Gypsy Prince’ was a single group; the other four cultivars were in one group. The distribution of 45S rDNA loci in diploid hyacinth cultivars was relatively conservative, while the locus number and distribution of 5S rDNA and telomeric repeats were highly polymorphic. The FISH physical mapping in this study provides a basic understanding of the karyotype evolution of hyacinth species, which could increase the understanding of the evolutionary history and phylogenetic relationships of hyacinths.
References
<p>Alexandre, M.A.V., Duarte, L.M.L., Rodrigues, L.K., Ramos, A.F. & Harakava, R. (2017) Hyacinth mosaic virus infecting <em>Hyacinthus</em> sp. plants in Brazil. <em>Tropical Plant Pathology</em> 42: 51–54. https://doi.org/10.1007/s40858-016-0121-5</p>
<p>Arano, H. Cytological studies in subfamily Carduoideae(Compositae) of Japan. IX. (1963) The karyotype analysis and phylogentic considerations on Pertya and Ainsliaca(2). <em>The Botanical Magazine, Tokyo</em> 76: 32–39. https://doi.org/10.15281/jplantres1887.76.32</p>
<p>Ba, L.J., Li, Z.M., Chen, G.F. & Deng, H.P. (2016) Karyotype and chromosome numbers of three species from <em>Elsholtzia</em>. <em>Acta Botanica Boreali-Occidentalia Sinica</em> 36: 923–929.</p>
<p>Cao, Q.Z., Lian, Y.Q., Wang, L.J., Zhang, Q., Zhao, Y.Q., Jia, G.X. & He, H.B. (2019) Physical mapping of 45S rDNA loci in <em>Lilium</em> OT hybrids and interspecific hybrids with <em>Lilium</em> regale. <em>Scientia Horticulturae</em> 252: 48–54. https://doi.org/10.1016/j.scienta.2019.03.035</p>
<p>Chester, M., Leitch, A.R., Soltis, P.S. & Soltis, D.E. (2010) Review of the application of modern cytogenetic methods (FISH/GISH) to the study of reticulation (polyploidy/hybridization). <em>Genes</em> 1: 166–192. https://doi.org/10.3390/genes1020166</p>
<p>Cox, A.V., Bennett, S.T., Parokonny, A.S., Kenton, A., Callimassia, M.A. & Bennett, M.D. (1993) Comparison of plant telomere locations using a PCR-generated synthetic probe. <em>Annals of botany</em> 72: 239–247. https://doi.org/10.1006/anbo.1993.1104</p>
<p>Fang, L., Yang, B., Zhang, W.N., Xin, H.Y., Gao, T.T., Shi, J.S., Guo, J. & Xi, M.L. (2014) The Ploidy level investigation and FISH analysis of the progenies from allotriploid <em>Lilium</em> as male. <em>Molecular Plant Breeding</em> 12: 138–143.</p>
<p>Fuchs, J., Brandes, A. & Schubert, I. (1996)Telomere sequence localization and karyotype evolution in higher plants. <em>Plant Systematics and Evolution</em> 196: 227–241. https://doi.org/10.1007/BF00982962</p>
<p>He, Y.H., Su, X.Q. & Hu, F.R. (2021) The Comparative analysis of karyotype between diploid hyacinth ‘Yellow Stone’ and ‘Red Pearl’. <em>Molecular Plant Breeding</em>. Available from: http://kns.cnki.net/kcms/detail/46.1068.S.20210514.1534.016.html (accessed 14 May 2021)</p>
<p>Hont, A. D’., Paget-Goy, A., Escoute, J. & Carreel, F. (2000) The interspecific genome structure of cultivated banana, <em>Musa</em> spp. revealed by genomic DNA in situhybridization. <em>Theoretical and Applied Genetics</em> 100: 177–183.</p>
<p>Hu, F.R., He, G.R., Wang, F. & Ren, C. (2015) The identification of the Hyacinth hybrid progeny by the method of ISSR molecular marker. <em>Molecular Plant Breeding</em> 13: 1336–1342.</p>
<p>Hu, F.R., Ren, C., Bao, R.L. & Liu, G.X. (2011) Chromosomes analysis of five diploid garden hyacinth species.<em> Scientia Horticulturae</em> 131: 82–87. https://doi.org/10.1016/j.scienta.2011.09.023</p>
<p>Hu, F.R., Wang, F., Bao, R.L. & Xie, W.R. (2012) Pretreatment reagents for <em>Hyacinthus</em> root tip and karyotype analysis. <em>Acta Botanica Boreali-Occidentalia Sinica</em> 32: 2030–2034.</p>
<p>Ilnicki, T. (2014) Plant biosystematics with the help of cytology and cytogenetics. Caryologia 67: 199–208. https://doi.org/10.1080/00087114.2014.931642</p>
<p>Lan, H., Chen, C.L., Miao, Y., Yu, C.X., Guo, W.W., Xu, Q. & Deng, X.X. (2016) Fragile sites of ‘Valencia’ sweet orange (<em>Citrus sinensis</em>) chromosomes are related with active 45s rDNA. <em>PLoS ONE</em> 11: e0151512. https://doi.org/10.1371/journal.pone.0151512</p>
<p>Lan, Y., QU, L.W., Xin, H.Y., Gong, H.L., Lei, J.J. & Xi, M.L. (2018) Physical mapping of rDNA and karyotype analysis in <em>Tulipa sinkiangensis</em> and <em>T. schrenkii</em>. <em>Scientia Horticulturae</em> 240: 638–644. https://doi.org/10.1016/j.scienta.2018.06.055</p>
<p>Levan, A., Fredga, K. & Sandberg, A.A. (1964) Nomenclature for centrometic position on chromosomes. <em>Heredity</em> 52: 201–220. https://doi.org/10.1111/j.1601-5223.1964.tb01953.x</p>
<p>Li, M.X. & Chen, R.Y. (1985) On the standardization of karyotype analysis. <em>Journal of Wuhan Botanical Research</em> 3: 297–302.</p>
<p>Li, M.X. & Zhang, Z,P. (1996) <em>Plant chromosome and its research technology</em>. China Agricultural Publishing House, Beijing, China, 15 pp.</p>
<p>Li, Y. (2015) <em>Studies on the chromosome ploidy and FISH analyses of mulberry plants (Morus L.)</em>. Southwest University, Chongqing, China, pp. 51–52.</p>
<p>Lim, K.B. & Van Tuyl, J.M. (2002) Identification of parental chromosomes and detection of ribosomal DNA sequences in interspecific hybrids of <em>Lilium</em> revealed by multicolor in situ hybridization. <em>Acta Horticulturae</em> 570: 403–408. https://doi.org/10.17660/ActaHortic.2002.570.57</p>
<p>Lim, K.B. (2000) <em>Introgression breeding through interspecific polyploidisation in lily</em>. Wageningen University and Research center, Wageningen, the Netherlands, pp. 21–23.</p>
<p>Linnaeus, C. (1753) <em>Species Plantarum</em>. Laurentius Salvius, Sweden, 317 pp.</p>
<p>Liu, Y.L., Liu, L.J. & Peng, R.H. (2018) Development of FISH and its application in plant genome research. <em>Molecular Plant Breeding</em>. 16: 5696–5703.</p>
<p>Liu, Z.L., Zhang, D., Hong, D.Y. & Wang, X.R. (2003) Chromosomal localization of 5S and 18S-5.8S-25S ribosomal DNA sites in five Asian pines using fluorescence in situ hybridization. T<em>heoretical and Applied Genetics</em> 106: 198–204. https://doi.org/10.1007/s00122-002-1024-z</p>
<p>Miyamoto, K., Kotake, T., Boncela, A.J., Saniewski, M. & Ueda, J. (2015) Hormonal regulation of gummosis and composition of gums from Bulbs of hyacinth (<em>Hyacinthus orientalis</em>). <em>Journal of Plant Physiology</em> 174: 1–4. https://doi.org/10.1016/j.jplph.2014.10.007</p>
<p>Nguyen, T.X., Lee, S.I., Rai, R., Kim, N.S. & Kim, J.H. (2016) Ribosomal DNA locus variation and REMAP analysis of the diploid and triploid complexes of<em> Lilium lancifolium</em>. <em>Genome</em>59: 551–564. https://doi.org/10.1139/gen-2016-0011</p>
<p>Qu, M.M. (2018) <em>Comparative localization of 5S and 45S rDNA in strawberry species</em>. Jiangsu Normal University, Xuzhou, China, 22 pp.</p>
<p>Richards, E.J. (1988) Ausubel M. Isolation of a higher eukaryotic telomere from <em>Arabidopsis thaliana</em>. <em>Cell</em> 53: 127–136. https://doi.org/10.1016/0092-8674(88)90494-1</p>
<p>Rosato, M., Moreno-Saiz, J.C., Galián, J.A. & Rosselló, J.A. (2015) Evolutionary site-number changes of ribosomal DNA loci during speciation: complex scenarios of ancestral and more recent polyploid events. <em>AoB Plants</em> 7: plv135. https://doi.org/10.1093/aobpla/plv135</p>
<p>She, C.W. & Jiang, X.H. (2015) Detection of 45S rDNA and telomere sequences and karyotype analysis of <em>Sagittaria trifolia </em>L.. <em>Journal of Wuhan Botanical Research</em> 33: 507–512.</p>
<p>She, C.W. & Luo, Y. (2019) Detection of 45S rDNA and karyotype analysis of <em>Caesalpinia decapetala</em> (Roth) Alston. <em>Acta Botanica Boreali-Occidentalia Sinica </em>39: 911–916.</p>
<p>Shibata, F., Matsusaki, Y. & Hizume, M. (2016) A comparative analysis of multi-probe fluorescence in situ hybridisation (FISH) karyotypes in 26 <em>Pinus</em> species (Pinaceae). <em>Cytologia </em>81: 409–421. https://doi.org/10.1508/cytologia.81.409</p>
<p>Stebbins, G.L. (1971) <em>Chromosomal Evolution in Higher Plants</em>. Edward Arnold Ltd, London, the UK, pp. 72–123.</p>
<p>Su, X.Q., Wang, F. & Hu, F.R. (2019) Karyotype analysis of 3 diploid hyacinth cultivars. <em>Acta Agriculturae Zhejiangensis</em> 31: 1509–1515.</p>
<p>Su, X.Q., Wang, F. & Hu, F.R. (2020) Karyotypes comparative analysis of different hyacinth horticultural varieties. <em>Molecular Plant Breeding</em>18: 4053–4059.</p>
<p>Tan, J.R., Wang, J., Gao, H.B., Yi, X.W., Jiang, S. & Pan, H.T. (2019) Distribution of 45S and 5S rDNA in 17 <em>Rosa</em> species of China. <em>Acta Botanica Boreali-Occidentalia Sinica</em> 39: 1333–1343.</p>
<p>Thomas, H.M., Harper, J.A. & Morgan, W.G. (2001) Gross chromosome rearrangements are occurring in an accession of the grass <em>Lolium rigidum</em>. <em>Chromosome Research</em> 9: 585–590. https://doi.org/10.1023/A:1012499303514</p>
<p>Van Tuyl, J.M. (1982) Breeding for resistance to yellow disease of <em>Hyacinths</em>. II. Influence of flowering time, leaf characters, stomatnd chromosome number on the degree of resistance. <em>Euphytica</em> 31: 621–628. https://doi.org/10.1007/BF00039200</p>
<p>Wang, D.R., Du, P., Pei, Z.Y., Zhuang, L.F. & Qi, Z.J. (2017) Development and application of high resolution karyotypes of wheat “Chinese Spring” aneuploids. <em>Acta Agronomica Sinica</em> 43: 1575–1587. https://doi.org/10.3724/SP.J.1006.2017.01575</p>
<p>Wang, J.,Yang, B.J., Pan, L.Y., Cai, M., Ding, X.L., Pan, H.T. & Zhang, Q.X. Karyotype analysis of <em>Lagerstroemia</em> species with 45S rDNA-FISH. <em>Acta Botanica Boreali-Occidentalia Sinica</em> 36: 30–36.</p>
<p>Wang, L.J., Ren, X.L., Sheng, M.Y., Du, J.Y. & Wen, P.C. (2017) Study on karyotype, C-banding and rDNA chromosome locus in <em>Nicotiana alata.</em> <em>Acta Tabacaria Sinica</em> 23: 95–101.</p>
<p>Wang, Y., Nan, H., Wang, X.R., Zhang, L., Liu, Y., Chen, Q. & Tang, H.R. (2012) Research progress on physical mapping to chromosome and phylogenetic inference of 45S and 5S rDNA in fruit trees. <em>Journal of Fruit Science</em> 29: 253–261.</p>
<p>Xie, M.M. & Wu, Q.S. (2018) Arbuscular mycorrhizal fungi regulate flowering of <em>hyacinths orientalis</em> L. Anna marie. <em>Emirates Journal of Food and Agriculture</em> 30: 144–149. https://doi.org/10.9755/ejfa.2018.v30.i2.1614</p>
<p>Xie, M.M. & Wu, Q.S. (2017) Mycorrhiza modulates morphology, color and duration of flowers in hyacinth. <em>Biotechnology</em> 16: 116–122. https://doi.org/10.3923/biotech.2017.116.122</p>
<p>Xu, Y.H. & Li, L.J. (2010) Physical mapping of the 45S rDNA and 5S rDNA in the peanut(<em>Arachis hypogaea</em> L.). <em>Journal of Wuhan Botanical Research</em> 28: 649–653.</p>
<p>Yukio, A., Hitomi, Y.A. & Masumi, E. (2010) Morphological diversity of chromosomes bearing ribosomal DNA loci in Brachiaria species. <em>Grassland Science</em> 56: 217–223. https://doi.org/10.1111/j.1744-697X.2010.00197.x</p>
<p>Zhao, Q., Chen, Z., Yang, X., Dang, J.B., Wang, W.X., Sun, H.Y., Liang, L.G. & Xiang, S.Q. (2016) Chromosome localization of 5S rDNA of natural tetraploids and their corresponding diploids in <em>Citrus</em> by fluorescence in situ hybridization. <em>Journal of Southwest University (Natural Science Edition)</em> 38: 34–39.</p>
<p>Arano, H. Cytological studies in subfamily Carduoideae(Compositae) of Japan. IX. (1963) The karyotype analysis and phylogentic considerations on Pertya and Ainsliaca(2). <em>The Botanical Magazine, Tokyo</em> 76: 32–39. https://doi.org/10.15281/jplantres1887.76.32</p>
<p>Ba, L.J., Li, Z.M., Chen, G.F. & Deng, H.P. (2016) Karyotype and chromosome numbers of three species from <em>Elsholtzia</em>. <em>Acta Botanica Boreali-Occidentalia Sinica</em> 36: 923–929.</p>
<p>Cao, Q.Z., Lian, Y.Q., Wang, L.J., Zhang, Q., Zhao, Y.Q., Jia, G.X. & He, H.B. (2019) Physical mapping of 45S rDNA loci in <em>Lilium</em> OT hybrids and interspecific hybrids with <em>Lilium</em> regale. <em>Scientia Horticulturae</em> 252: 48–54. https://doi.org/10.1016/j.scienta.2019.03.035</p>
<p>Chester, M., Leitch, A.R., Soltis, P.S. & Soltis, D.E. (2010) Review of the application of modern cytogenetic methods (FISH/GISH) to the study of reticulation (polyploidy/hybridization). <em>Genes</em> 1: 166–192. https://doi.org/10.3390/genes1020166</p>
<p>Cox, A.V., Bennett, S.T., Parokonny, A.S., Kenton, A., Callimassia, M.A. & Bennett, M.D. (1993) Comparison of plant telomere locations using a PCR-generated synthetic probe. <em>Annals of botany</em> 72: 239–247. https://doi.org/10.1006/anbo.1993.1104</p>
<p>Fang, L., Yang, B., Zhang, W.N., Xin, H.Y., Gao, T.T., Shi, J.S., Guo, J. & Xi, M.L. (2014) The Ploidy level investigation and FISH analysis of the progenies from allotriploid <em>Lilium</em> as male. <em>Molecular Plant Breeding</em> 12: 138–143.</p>
<p>Fuchs, J., Brandes, A. & Schubert, I. (1996)Telomere sequence localization and karyotype evolution in higher plants. <em>Plant Systematics and Evolution</em> 196: 227–241. https://doi.org/10.1007/BF00982962</p>
<p>He, Y.H., Su, X.Q. & Hu, F.R. (2021) The Comparative analysis of karyotype between diploid hyacinth ‘Yellow Stone’ and ‘Red Pearl’. <em>Molecular Plant Breeding</em>. Available from: http://kns.cnki.net/kcms/detail/46.1068.S.20210514.1534.016.html (accessed 14 May 2021)</p>
<p>Hont, A. D’., Paget-Goy, A., Escoute, J. & Carreel, F. (2000) The interspecific genome structure of cultivated banana, <em>Musa</em> spp. revealed by genomic DNA in situhybridization. <em>Theoretical and Applied Genetics</em> 100: 177–183.</p>
<p>Hu, F.R., He, G.R., Wang, F. & Ren, C. (2015) The identification of the Hyacinth hybrid progeny by the method of ISSR molecular marker. <em>Molecular Plant Breeding</em> 13: 1336–1342.</p>
<p>Hu, F.R., Ren, C., Bao, R.L. & Liu, G.X. (2011) Chromosomes analysis of five diploid garden hyacinth species.<em> Scientia Horticulturae</em> 131: 82–87. https://doi.org/10.1016/j.scienta.2011.09.023</p>
<p>Hu, F.R., Wang, F., Bao, R.L. & Xie, W.R. (2012) Pretreatment reagents for <em>Hyacinthus</em> root tip and karyotype analysis. <em>Acta Botanica Boreali-Occidentalia Sinica</em> 32: 2030–2034.</p>
<p>Ilnicki, T. (2014) Plant biosystematics with the help of cytology and cytogenetics. Caryologia 67: 199–208. https://doi.org/10.1080/00087114.2014.931642</p>
<p>Lan, H., Chen, C.L., Miao, Y., Yu, C.X., Guo, W.W., Xu, Q. & Deng, X.X. (2016) Fragile sites of ‘Valencia’ sweet orange (<em>Citrus sinensis</em>) chromosomes are related with active 45s rDNA. <em>PLoS ONE</em> 11: e0151512. https://doi.org/10.1371/journal.pone.0151512</p>
<p>Lan, Y., QU, L.W., Xin, H.Y., Gong, H.L., Lei, J.J. & Xi, M.L. (2018) Physical mapping of rDNA and karyotype analysis in <em>Tulipa sinkiangensis</em> and <em>T. schrenkii</em>. <em>Scientia Horticulturae</em> 240: 638–644. https://doi.org/10.1016/j.scienta.2018.06.055</p>
<p>Levan, A., Fredga, K. & Sandberg, A.A. (1964) Nomenclature for centrometic position on chromosomes. <em>Heredity</em> 52: 201–220. https://doi.org/10.1111/j.1601-5223.1964.tb01953.x</p>
<p>Li, M.X. & Chen, R.Y. (1985) On the standardization of karyotype analysis. <em>Journal of Wuhan Botanical Research</em> 3: 297–302.</p>
<p>Li, M.X. & Zhang, Z,P. (1996) <em>Plant chromosome and its research technology</em>. China Agricultural Publishing House, Beijing, China, 15 pp.</p>
<p>Li, Y. (2015) <em>Studies on the chromosome ploidy and FISH analyses of mulberry plants (Morus L.)</em>. Southwest University, Chongqing, China, pp. 51–52.</p>
<p>Lim, K.B. & Van Tuyl, J.M. (2002) Identification of parental chromosomes and detection of ribosomal DNA sequences in interspecific hybrids of <em>Lilium</em> revealed by multicolor in situ hybridization. <em>Acta Horticulturae</em> 570: 403–408. https://doi.org/10.17660/ActaHortic.2002.570.57</p>
<p>Lim, K.B. (2000) <em>Introgression breeding through interspecific polyploidisation in lily</em>. Wageningen University and Research center, Wageningen, the Netherlands, pp. 21–23.</p>
<p>Linnaeus, C. (1753) <em>Species Plantarum</em>. Laurentius Salvius, Sweden, 317 pp.</p>
<p>Liu, Y.L., Liu, L.J. & Peng, R.H. (2018) Development of FISH and its application in plant genome research. <em>Molecular Plant Breeding</em>. 16: 5696–5703.</p>
<p>Liu, Z.L., Zhang, D., Hong, D.Y. & Wang, X.R. (2003) Chromosomal localization of 5S and 18S-5.8S-25S ribosomal DNA sites in five Asian pines using fluorescence in situ hybridization. T<em>heoretical and Applied Genetics</em> 106: 198–204. https://doi.org/10.1007/s00122-002-1024-z</p>
<p>Miyamoto, K., Kotake, T., Boncela, A.J., Saniewski, M. & Ueda, J. (2015) Hormonal regulation of gummosis and composition of gums from Bulbs of hyacinth (<em>Hyacinthus orientalis</em>). <em>Journal of Plant Physiology</em> 174: 1–4. https://doi.org/10.1016/j.jplph.2014.10.007</p>
<p>Nguyen, T.X., Lee, S.I., Rai, R., Kim, N.S. & Kim, J.H. (2016) Ribosomal DNA locus variation and REMAP analysis of the diploid and triploid complexes of<em> Lilium lancifolium</em>. <em>Genome</em>59: 551–564. https://doi.org/10.1139/gen-2016-0011</p>
<p>Qu, M.M. (2018) <em>Comparative localization of 5S and 45S rDNA in strawberry species</em>. Jiangsu Normal University, Xuzhou, China, 22 pp.</p>
<p>Richards, E.J. (1988) Ausubel M. Isolation of a higher eukaryotic telomere from <em>Arabidopsis thaliana</em>. <em>Cell</em> 53: 127–136. https://doi.org/10.1016/0092-8674(88)90494-1</p>
<p>Rosato, M., Moreno-Saiz, J.C., Galián, J.A. & Rosselló, J.A. (2015) Evolutionary site-number changes of ribosomal DNA loci during speciation: complex scenarios of ancestral and more recent polyploid events. <em>AoB Plants</em> 7: plv135. https://doi.org/10.1093/aobpla/plv135</p>
<p>She, C.W. & Jiang, X.H. (2015) Detection of 45S rDNA and telomere sequences and karyotype analysis of <em>Sagittaria trifolia </em>L.. <em>Journal of Wuhan Botanical Research</em> 33: 507–512.</p>
<p>She, C.W. & Luo, Y. (2019) Detection of 45S rDNA and karyotype analysis of <em>Caesalpinia decapetala</em> (Roth) Alston. <em>Acta Botanica Boreali-Occidentalia Sinica </em>39: 911–916.</p>
<p>Shibata, F., Matsusaki, Y. & Hizume, M. (2016) A comparative analysis of multi-probe fluorescence in situ hybridisation (FISH) karyotypes in 26 <em>Pinus</em> species (Pinaceae). <em>Cytologia </em>81: 409–421. https://doi.org/10.1508/cytologia.81.409</p>
<p>Stebbins, G.L. (1971) <em>Chromosomal Evolution in Higher Plants</em>. Edward Arnold Ltd, London, the UK, pp. 72–123.</p>
<p>Su, X.Q., Wang, F. & Hu, F.R. (2019) Karyotype analysis of 3 diploid hyacinth cultivars. <em>Acta Agriculturae Zhejiangensis</em> 31: 1509–1515.</p>
<p>Su, X.Q., Wang, F. & Hu, F.R. (2020) Karyotypes comparative analysis of different hyacinth horticultural varieties. <em>Molecular Plant Breeding</em>18: 4053–4059.</p>
<p>Tan, J.R., Wang, J., Gao, H.B., Yi, X.W., Jiang, S. & Pan, H.T. (2019) Distribution of 45S and 5S rDNA in 17 <em>Rosa</em> species of China. <em>Acta Botanica Boreali-Occidentalia Sinica</em> 39: 1333–1343.</p>
<p>Thomas, H.M., Harper, J.A. & Morgan, W.G. (2001) Gross chromosome rearrangements are occurring in an accession of the grass <em>Lolium rigidum</em>. <em>Chromosome Research</em> 9: 585–590. https://doi.org/10.1023/A:1012499303514</p>
<p>Van Tuyl, J.M. (1982) Breeding for resistance to yellow disease of <em>Hyacinths</em>. II. Influence of flowering time, leaf characters, stomatnd chromosome number on the degree of resistance. <em>Euphytica</em> 31: 621–628. https://doi.org/10.1007/BF00039200</p>
<p>Wang, D.R., Du, P., Pei, Z.Y., Zhuang, L.F. & Qi, Z.J. (2017) Development and application of high resolution karyotypes of wheat “Chinese Spring” aneuploids. <em>Acta Agronomica Sinica</em> 43: 1575–1587. https://doi.org/10.3724/SP.J.1006.2017.01575</p>
<p>Wang, J.,Yang, B.J., Pan, L.Y., Cai, M., Ding, X.L., Pan, H.T. & Zhang, Q.X. Karyotype analysis of <em>Lagerstroemia</em> species with 45S rDNA-FISH. <em>Acta Botanica Boreali-Occidentalia Sinica</em> 36: 30–36.</p>
<p>Wang, L.J., Ren, X.L., Sheng, M.Y., Du, J.Y. & Wen, P.C. (2017) Study on karyotype, C-banding and rDNA chromosome locus in <em>Nicotiana alata.</em> <em>Acta Tabacaria Sinica</em> 23: 95–101.</p>
<p>Wang, Y., Nan, H., Wang, X.R., Zhang, L., Liu, Y., Chen, Q. & Tang, H.R. (2012) Research progress on physical mapping to chromosome and phylogenetic inference of 45S and 5S rDNA in fruit trees. <em>Journal of Fruit Science</em> 29: 253–261.</p>
<p>Xie, M.M. & Wu, Q.S. (2018) Arbuscular mycorrhizal fungi regulate flowering of <em>hyacinths orientalis</em> L. Anna marie. <em>Emirates Journal of Food and Agriculture</em> 30: 144–149. https://doi.org/10.9755/ejfa.2018.v30.i2.1614</p>
<p>Xie, M.M. & Wu, Q.S. (2017) Mycorrhiza modulates morphology, color and duration of flowers in hyacinth. <em>Biotechnology</em> 16: 116–122. https://doi.org/10.3923/biotech.2017.116.122</p>
<p>Xu, Y.H. & Li, L.J. (2010) Physical mapping of the 45S rDNA and 5S rDNA in the peanut(<em>Arachis hypogaea</em> L.). <em>Journal of Wuhan Botanical Research</em> 28: 649–653.</p>
<p>Yukio, A., Hitomi, Y.A. & Masumi, E. (2010) Morphological diversity of chromosomes bearing ribosomal DNA loci in Brachiaria species. <em>Grassland Science</em> 56: 217–223. https://doi.org/10.1111/j.1744-697X.2010.00197.x</p>
<p>Zhao, Q., Chen, Z., Yang, X., Dang, J.B., Wang, W.X., Sun, H.Y., Liang, L.G. & Xiang, S.Q. (2016) Chromosome localization of 5S rDNA of natural tetraploids and their corresponding diploids in <em>Citrus</em> by fluorescence in situ hybridization. <em>Journal of Southwest University (Natural Science Edition)</em> 38: 34–39.</p>