Genomic changes in generations of synthetic rapeseed-like allopolyploid grown under selection     

Alexandra V. Amosova  Lyudmila V. Zemtsova  Olga Yu. Yurkevich  Elena N. Zhidkova  Tomasz Książczyk  Natalia G. Shostak  Anatoly A. Muravlev  Anna M. Artemyeva  Tatiana E. Samatadze  Svyatoslav A. Zoshchuk  Olga V. Muravenko 《Euphytica》2017,213(9):217

Resynthesized Brassica napus L. is an important source for broadening genetic diversity and producing lines with desired characteristics. It is also a fine model to study the processes of genomic reorganizations in recently formed polyploids. We firstly performed molecular cytogenetic characterization of newly resynthesized rapeseed (B. rapa ssp. narinosa × B. oleracea ssp. capitata) and its parental species, and also examined genomic changes in hybrids of the succeeding generations grown under pressure of selection of yellow-seeded progeny. For karyotype studies, FISH/GISH with 45S, 5S rDNA, C genome specific BoB014O06 BAC clone and genomic DNA of parental B. rapa was performed. Synthetic S0–S2 hybrids had common rapeseed karyotypes (2n = 38) including 14 loci of 45S rDNA sites and 10 loci of 5S rDNA. Progeny selection led to gradual deletion of C genome chromosomes in hybrid karyotypes. So, in karyotypes of S6 and S7 hybrids, the chromosome number was reduced to 2n = 20–22, and only chromosomes of A genome bearing 10–13 loci of 45S rDNA and 8–10 loci of 5S rDNA, variations in chromosome number, chromosome rearrangements as well as examples of trisomy and monosomy were revealed. Our findings indicate an enhanced genome instability in resynthesized rapeseed lines developed under the pressure of selection which might lead to chromosome rearrangements or/and deletions and even elimination of the whole parental genome in hybrids in succeeding generations. The approach can be useful for the development of rapeseed lines with trisomy, chromosome addition/substitution lines important for genetics and plant breeding.  相似文献   

Karyotype analysis and physical mapping of 45S rRNA genes in Hydrangea species by fluorescence in situ hybridization     

K. Van Laere  J. Van Huylenbroeck    E. Van Bockstaele 《Plant Breeding》2008,127(3):301-307

Detailed karyotypes of Hydrangea macrophylla, Hydrangea paniculata and Hydrangea quercifolia were constructed on the basis of arm lengths and centromeric index, together with 45S rDNA fluorescence in situ hybridization. Although the chromosomes were small, they were well distinguishable for all species. Chromosome morphology and karyotypes were different for the three species. H. macrophylla had six metacentric (M), eight submetacentric (SM) and four subtelocentric (ST) chromosomes. The karyotype of H. paniculata contained seven M, 10 SM and one ST chromosomes and H. quercifolia had six M, 10 SM and two ST chromosomes. The variability among three species also was expressed by 45S rDNA signals. H. macrophylla had a nucleolar organizing region on chromosome 2, H. paniculata had 45S rDNA signals on chromosomes 2, 5 and 11 and H. quercifolia on chromosomes 3 and 8. Hybridization signal always was distally on the short arm but the strength of the signals was different for the three species. The chromosome portraits made in this study will be used to trace chromosome behaviour in interspecific hybrids resulting from breeding work between the three species.  相似文献   

Karyotype and meiotic analyses of six species in the subtribe Chrysantheminae   总被引：2，自引：1，他引：1  

Jian Li  Su-Mei Chen  Fa-Di Chen  Wei-Min Fang 《Euphytica》2008,164(1):293-301

The karyotypes and meiotic behaviour of six Chrysantheminae species are investigated. Pyrethrum coccineum (Willd.) Worosch. is a tetraploid, while the other five species (Argyranthemum frutescens (L.) Sch.-Bip., Opisthopappus taihangensis (Ling) shih, Crossostephium chinense (L.) Makino, Tanacetum vulgare L. and P. parthenium (L.) Sm.) are all diploids. Their karyotypes consist mainly of median centromere and submedian centromere chromosomes, although C. chinense also has two terminal centromere chromosomes, and P. parthenium two subterminal centromere chromosomes. No satellited chromosomes are observed in any of the six species. All the species have a 2A type karyotype, except for P. coccineum which is 3A. The meiotic behaviour in the pollen mother cells (PMCs) of all six species is essentially normal, with metaphase I chromosome pairing configurations in the diploid species predominantly showing 9II, while P. coccineum shows 18II. A low frequency of quadrivalents (and trivalents) and chromosome bridges/lagging chromosomes is observed.  相似文献   

Karyotype analysis of the genus Clivia by Giemsa and fluorochrome banding and in situ hybridization   总被引：2，自引：0，他引：2  

Y. Ran  B.G. Murray  K.R.W. Hammett 《Euphytica》1999,106(2):139-147

The karyotypes of species in the genus Clivia were analyzed by using Giemsa C-banding, fluorochrome staining, silver impregnation and in situ hybridization. Banded ideograms were established with computer aided image analysis. A chromosome number of 2n = 22 and a similar basic karyotype, based on relative chromosome length and arm ratio, was found in all the four species. There were clear differences in banding pattern between the species which allowed their karyotypes, and consequently the species, to be unambiguously identified. Apart from at the centromere, heterochromatin was mainly distributed on the short arms of the smaller chromosomes. Amounts of heterochromatin in C. miniata and C. gardenii were greater than in the other two species. The number of pairs of rDNA sites, identified by in situ hybridization, ranged from one to three. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

The biological characters and polyploidy of progenies in hybridization in 4×–2× crosses in <Emphasis Type="Italic">Dianthus caryophyllus</Emphasis>     

Xuhong Zhou  Yan Su  Xiumei Yang  Yiping Zhang  Shengchong Li  Min Gui  Jihua Wang 《Euphytica》2017,213(6):118

Crosses were carried out between tetraploid Dianthus caryophyllus cv ‘Butterfly’ (2n = 4×= 60) and seven diploid cultivars (2n = 2×= 30). Fewer seeds were obtained and the low seed germination was found which suggested the post-fertilization barrier in 4×–2× crosses. 12 progeny were obtained from 5 crossing combinations. Chromosome analysis revealed that they consisted of 5 triploid hybrid plants and 7 tetraploid hybrid plants, suggesting that unreduced male gamete maybe be involved in polyploid formation. Various flower shapes and colours were observed in the polyploid progenies, showing that sexual polyploidization results in greater variability and fitness. The hybrids obtained by 4×–2× crosses showed the flower-size intermediate between the parents or larger than the parents. Some favourable characters of parents such as flower shape, flower colour and resistance to Fusarium oxysporum, were successfully transmitted to the hybrids. Since polyploid hybrids have some of the profitable characters of the parents, they are expected to be used for future breeding in carnation.  相似文献   

玉米各亚种的核型研究     

张赞平 《华北农学报》1995,10(3):60-67

研究了玉米８个亚种，２个亚型的核型。所有材料的根尖细胞染色体数目均为２ｎ＝２０，主要由中部和近中部着丝点染色体组成，第６对染色体短臂均具随体。但臂比值不同，可区分为Ａ１（ｍ染色体）、Ａ２（ｓｍ）、Ａ３（ｓｔ）三类。在核型中具中部着丝点染色体的数目，罕见栽培或原始类型多于广泛栽培的类型。玉米各亚种的核型进化的趋势是由对称向不对称方向发展。  相似文献   

Interspecific hybridization in <Emphasis Type="Italic">Sarcococca</Emphasis> supported by analysis of ploidy level,genome size and genetic relationships     

Hanne Denaeghel  Katrijn Van Laere  Leen Leus  Johan Van Huylenbroeck  Marie-Christine Van Labeke 《Euphytica》2017,213(7):149

Knowledge of ploidy level differences, genome size and genetic relationships between species facilitates interspecific hybridization in ornamentals. For Sarcococca (Buxaceae) only limited (cyto)genetic information is available. The aim of this study was to determine the genome size and chromosome number and to unravel the genetic relationships of a breeder’s collection using AFLP marker analysis. Based on these results, interspecific crosses were made and the efficiency and hybrid status was verified. Two groups of diploid plants (2n = 2x = 24) were observed, with either a genome size of 4.11–4.20 or 7.25–9.63 pg/2C. All the tetraploid genotypes (2n = 4x = 48) had genome sizes ranging from 7.91 to 8.18 pg/2C. In crosses between parents with equal ploidy level and genome size a higher crossing efficiency (on average 58% of the hybridizations resulting in fruits) and more true hybrids (on average 96% of the offspring) were obtained compared to crosses between plants with different genome size and ploidy level (on average 23% fruits and 24% hybrids, respectively). In none of the cross combinations, the ploidy level or genome size was found to be a complete hybridization barrier, although unilateral incongruity was found in some cross combinations. Distant genetic relationships did not hamper the hybridization within Sarcococca genotypes. Our findings will contribute to a more efficient breeding program and a faster achievement of hybrids with an added value.  相似文献   

Slow-growing pollen-tube of colchicine-induced 2n pollen responsible for low triploid production rate in <Emphasis Type="Italic">Populus</Emphasis>     

Chenguang Zhao  Mengdi Tian  Yanjie Li  Pingdong Zhang 《Euphytica》2017,213(4):94

To reveal the mechanism of low triploid production, meiotic observation, induction of 2n pollen by colchicine, hybridization of colchicine-induced 2n pollen and pollen germination were conducted in Populus tomentosa clone 5088. Meiosis of the PMCs was initiated 24 h after it was cultured in the greenhouse. Results showed that the meiosis developed in a consecutive, asynchronous process. Analysis of the occurrence rate of colchicine-induced 2n pollen using the GLM-univariate revealed significant differences among the dominant meiotic stages (F = 45.822, P = 0.000). Significant differences also occurred among various colchicine injection times (F = 10.150, P = 0.004). The most effective stage for colchicine-induced 2n pollen occurred between the zygotene to diakinesis substages. Sixty-eight triploids were confirmed with both flow cytometric analysis and chromosome number-counting among the 3346 offspring. The highest triploid induction rate was 13.2%—significantly lower than the expected triploid production rate of 47.0%—indicating that the colchicine-induced 2n pollen was weak during fertilization. We found positive correlation between the efficiency of triploid production and the frequency of colchicine-induced 2n pollen (r = 0.961, P = 0.001) which suggests that the triploid production rate increased as the occurrence rate of colchicine-induced 2n pollen increased. Analysis using the GLM-univariate indicated that both pollen types (F = 87.50, P < 0.001) and durations of pollen germination (F = 7.61, P = 0.002) did have significant effects on the lengths of pollen-tubes. Haploid pollen-tubes were significantly longer than colchicine-induced 2n pollen-tubes. This suggests that haploid pollen has an advantage during fertilization.  相似文献   

Karyotype analysis of eight wild <Emphasis Type="Italic">Tulipa</Emphasis> species native to China and the interspecific hybridization with tulip cultivars     

Lianwei Qu  Li Xue  Guimei Xing  Yanqiu Zhang  Juanjuan Chen  Wei Zhang  Jiajun Lei 《Euphytica》2018,214(4):65

The information of ploidy, karyotype and genetic relationship is useful for interspecific hybridization in ornamental plants. For Tulipa species native to China, very limited cytological information is available now. The objective of this study was to verify the chromosome number, karyotype and genetic relationship of the eight Tulipa species: T. edulis, T. schrenkii, T. iliensis, T. thianschanica, T. altaica, T. sinkiangensis, T. heterophylla and T. buhseana. And the interspecific crosses were made between T. altaica and ten tulip cultivars to obtain novel germplasm. The ovary-swelling, fruit-setting and bulblet formation rates were surveyed when different ploidy cultivars were used as female parents. This work confirmed that all eight species collected in China were diploid (2n?=?2x?=?24), among which chromosome numbers of T. thianschanica, T. sinkiangensis and T. heterophylla were firstly reported and the karyotypes of all any other species except for T. edulis were determined for the first time. The karyotypes of eight Tulipa species were classified as 3A, 4A or 3B. The results of interspecific hybridization showed significant difference when different ploidy cultivars were used as female parents. The highest fruit-setting rate was obtained when diploid cultivars were used as female parents crossed with diploid T. altaica, whereas the ovary swelling was observed in two out of four triploid cultivars as female parents, and no seeds were harvested when tetraploid cultivars were used as female parents. Our findings provided an effective means of cultivar improvement in tulip.  相似文献   

Overcoming obstacles to interspecific hybridization between <Emphasis Type="Italic">Gossypium hirsutum</Emphasis> and <Emphasis Type="Italic">G. turneri</Emphasis>     

Yu Chen  Yu Chen  Shouli Feng  Ting Zhao  Baoliang Zhou 《Euphytica》2018,214(2):35

Gossypium turneri, a wild cotton species (2n = 2X = 26, D₁₀D₁₀) originating from Mexico, possesses invaluable characteristics unavailable in the cultivated tetraploid cotton gene pool, such as caducous involucels at anthesis, resistance to insects and tolerance to abiotic stresses. However, transferring desired characteristics from wild species into cultivated cotton is often fraught with diverse obstacles. Here, Gossypium hirsutum (as the maternal parent) and G. turneri were crossed in the Hainan Province of China, and the obtained hybrid seeds (2n = 3X = 39, ADD₁₀) were treated with 0.075% colchicine solution for 48 h to double the chromosome complement in order to overcome triploid F₁ sterility and to generate a fertile hexaploid. Chromosome doubling was successful in four individuals. However, the new synthetic hexaploids derived from these individuals were still highly sterile, and no seeds were generated by selfing or crossing. Therefore, an embryo rescue technique was employed in an attempt to produce progenies from the new synthetic hexaploids. Consequently, a total of six large embryos were obtained on MSB2K medium supplemented with 0.5 mg l^?1 KIN and 250 mg l^?1 CH using ovules from backcrossing that were 3 days post-anthesis. Four grafted surviving seedlings were confirmed to be the progenies (pentaploids) of the new synthetic hexaploids using cytological observations and molecular markers. Eight putative fertile individuals derived from backcrossing the above pentaploids were confirmed using SSR markers and generated an abundance of normal seeds. This research lays a foundation for transferring desirable characteristics from G. turneri into upland cotton.  相似文献   

Cytological data on some wild tropical Vigna species and cultivars from cowpea and asparagus bean     

J. A. Frahm-Leliveld 《Euphytica》1965,14(3):251-270

A number of wild species of the genus Vigna were examined as to their chromosome numbers and mitotic metaphase plate configurations. Both the reported diploid numbers 20 and 22, were found or confirmed in a number of wild African species and one originating from East Asia. In species with the chromosome number 20 no deviations from this chromosome number were found. The identification of individual chromosomes is generally limited by their extremely small size. Moreover, the results did not tally with those of other authors. Therefore we abandoned the subject. Thirty-six cultivars of V. unguiculata and V. sesquipedalis of various tropical and subtropical sources were investigated, together with wild or subspontaneous types of V. unguiculata and some closely allied forms. The diploid chromosome numbers 22 and 24 have been mentioned in literature. The following results have been obtained:

1. 1
   A deviation of the chromosome number 22 ranging from 20 to 24 is noted in almost 10% of the cases analysed. Twenty-four chromosomes were found in the majority of these cascs.  相似文献