Monosomic Alien Addition Lines Research Articles

Monosomic Addition Lines of Flowering Chinese Cabbage ( B. campestris L. ssp. chinensis var. parachinensis L. H. Bailey)-Chinese Kale ( B. oleracea L. var. alboglabra L. H. Bailey)

Interspecific alien addition lines have played significant roles in gene mapping, intergenomic gene transfer and chromosomal homoeological identification between closely related species. Selection of alien addition lines was conducted by karyotype analysis and morphological observation with the reference of parents. Triploid interspecies hybrid (AAC, 2n = 3x = 29) was obtained from Brassica campestris ssp. chinensis var. parachinensis Qinglu 9601 (tetraploid, AAAA, 2n = 4x = 40) × B. oleracea var. alboglabra Baihua 9705 (diploid, CC, 2n = 2x = 18) by immature hybrid embryo culture in vitro. Five different alien monosomic addition lines (AA + C2, AA + C3, AA + C4, AA + C6, AA + C7) were obtained from the backcross progenies of AAC × AA. Each alien monosomic addition line has some specific morphological characters. It is feasible to obtain alien addition lines from the progenies of AAC × AA by karyotype analysis and morphological observation based on the reference of parents.

Progress on Transferring Elite Genes from Non-AA Genome Wild Rice into Oryza sativa through Interspecific Hybridization

The progress of research on transferring elite genes from non-AA genome wild rice into Oryza sativa through interspecific hybridization are in three respects, that is, breeding monosomic alien addition lines (MAALs), constructing introgression lines (ILs) and analyzing the heredity of the characters and mapping the related genes. There are serious reproductive barriers, mainly incrossability and hybrid sterility, in the interspecific hybridization of O. sativa with non-AA genome wild rice. These are the ‘bottleneck’ for transferring elite genes from wild rice to O. sativa. Combining traditional crossing method with biotechnique is a reliable way to overcome the reproductive barriers and to improve the utilizing efficiency of non-AA genome wild rice.

MOLECULAR APPROACHES TO CHARACTERIZING AND IMPROVING BULB COMPOSITION IN ONION

MOLECULAR APPROACHES TO CHARACTERIZING AND IMPROVING BULB COMPOSITION IN ONION

Biochemical and Genetic Analysis of Carbohydrate Accumulation in Allium cepa L

Onion and shallot (Allium cepa L.) exhibit wide variation in bulb fructan content, and the Frc locus on chromosome 8 conditions much of this variation. To understand the biochemical basis of Frc, we conducted biochemical and genetic analyses of Allium fistulosum (FF)-shallot (A. cepa Aggregatum group) alien monosomic addition lines (AALs; FF+1A-FF+8A) and onion mapping populations. Sucrose and fructan levels in leaves of FF+2A were significantly lower than in FF throughout the year, and the springtime activity of acid invertase was also lower. FF+8A showed significantly higher winter sucrose accumulation and sucrose phosphate synthase (SPS) activity. Inbred high fructan (Frc_) lines from the 'W202Ax Texas Grano 438' onion population exhibited significantly higher sucrose levels prior to bulbing than low fructan (frcfrc) lines. Sucrose synthase (SuSy) activity in these lines was correlated with leaf hexose content but not with Frc phenotype. Markers for additional candidate genes for sucrose metabolism were obtained by cloning a major SPS expressed in onion leaf and exhaustively mining onion expressed sequence tag resources. SPS and SuSy loci were assigned to chromosome 8 and 6, respectively, using AALs and linkage mapping. Further loci were assigned, using AALs, to chromosomes 1 (sucrose phosphate phosphatase), 2 (SuSy and three invertases) and 8 (neutral invertase). The concordance between chromosome 8 localization of SPS and elevated leaf sucrose levels conditioned by high fructan alleles at the Frc locus in bulb onion or alien monosomic additions of chromosome 8 in A. fistulosum suggest that the Frc locus may condition variation in SPS activity.

Monosomic alien addition lines: a new tool for studying and using plant genomics

Interspecies hybridization and backcrossing is a means to transfer desirable genes from one species to another in breeding programs of higher plants. Monosomic alien addition lines (MAALs) can be produced via addition of single chromosome of an alien donor species to the entire chromosome complement of the recipient species. MAALs are powerful tools for elucidating genome structure and transferring genes. Backcrossing of MAALs to the recipient parent results in plants containing short overlapping introgressions, which cover the entire donor genome. These introgression lines can be used as vectors of alien genomic libraries in a recipient genetic background. In addition, a complete set of MAALs also serves as a library of the donor genome dissected into individual chromosome entities, which facilitates high-throughput marker allocation to individual donor chromosomes, and marker assignments and syntenic relationships can be compared between the donor chromosomes and the respective orthologous recipient chromosomes. Meanwhile, MAALs can be used to study the introgression mechanism and the pairing status of homologous chromosomes. In this review, we presented the production and properties of MAALs and highlighted their advantages for genetic breeding and fundamental researches.

Using Allium alien monosomic addition lines to study chlorophyll degradation in stored Japanese bunching onion

SummaryChlorophyll (Chl) degradation and the formation of Chl derivatives in stored leaves of Japanese bunching onion (JBO; Allium fistulosum L., genome FF) were determined to elucidate the mechanism of Chl degradation by using alien monosomic addition lines (AMALs; FF+1A to FF+8A) of JBO from shallot (A. cepa L. Aggregatum group, genome AA). Year-round changes in Chl content in JBO and in the AMALs were also detected over 2 years. The Chl content in FF was significantly influenced by the alien chromosomes from shallot. In particular, the Chl contents of FF+4A or FF+5A, were higher in Winter than in FF, which suggests that chromosomes 4A and 5A from shallot had a larger influence on the formation of Chl than the other chromosomes. Chl contents in FF+3A and FF+5A decreased greatly in the leaves of AMALs and JBO during storage at 25°C, whereas in FF+4A the Chl content was the lowest compared to the control, FF. Chlorophyllide (Chlide) a, C132-hydroxychlorophyll (OHChl) a, pheophorbide a, and pheophytin (Phy) a, as derivatives of Chl a, were present mainly during storage of JBO and the AMALs. Phy alevels increased with Chl degradation, especially in FF+3A, while OHChl alevels in FF and FF+3A showed a decline during storage. In addition, Chlide alevels in all lines diminished during storage.Thus, Chl amay be degraded, in part, through Phy a, as well as Chlide aand OHChl a, in JBO and the AMALs during storage.

Cytogenetic analysis of F1, F2 and BC1 plants from intergeneric sexual hybridization between Sinapis alba and Brassica oleracea by genomic in situ hybridization

AbstractBy intergeneric sexual hybridization between Sinapis alba and Brassica oleracea, F1, F2 and BC1 progeny plants were produced. S. alba plants (genome SS, 2n = 24) were pollinated with B. oleracea (genome CC, 2n = 18), and the fertile F1 plants were pollinated with B. oleracea to obtain BC1 plants. GISH analysis showed that 10 out of 12 F1 plants had 12 S. alba chromosomes (one full S chromosome set) and nine B. oleracea chromosomes (one C chromosome sets), representing the expected hybrids. However, two F1 plants had 12 S chromosomes and 18 C chromosomes (two C chromosome sets), indicating unexpected hybrids. A maximum of three trivalents between C and S chromosomes were identified at metaphase I of semi‐fertile F1 pollen mother cells (PMCs), which indicates homology and chromosome pairing between these two genomes. The C genome had obviously been doubled in two F2 plants from selfed semi‐fertile F1 plants. BC1 plants consisted of 18 C chromosomes and different numbers of one, five and six additional S chromosomes, respectively. Monosomic alien addition lines developed in the present study can be used for B. oleracea breeding and Sinapis alba gene mapping.

Cytogenetic characterization of Solanum lycopersicoides Dun. Alien chromosome additions in cultured tomato

Cytogenetic analysis of five Solanum lycopersicoides monosomic alien addition lines of tomato was carried out. Meiotic analysis showed that additional chromosomes caused serious abnormalities. It was demonstrated that different chromosomes of S. lycopersicoides had different effects on chromosome pairing. For instance, associations formed between chromosomes II and IV of S. lycopersicoides and chromosomes of cultured tomato were trivalents, while chromosome XI in all cells was present as a univalent. Pachytene analysis showed that chromosomes of homeologous group II paired at their long arms, and their nucleolus organizer regions were of different sizes. The use of molecular markers provided accelerated identification of the introgression of S. lyvcopersicoides genetic material.

Analysis of F1 hybrid and BC1 monosomic alien addition line plants from Brassica oleracea × Sinapis alba by GISH

Sterile and semi-fertile F1 plants were obtained by intergeneric sexual hybridization between paternal Brassica oleracea var. alboglabra (genome CC, 2n=18) and maternal Sinapis alba (genome SS, 2n=24), BC1 plants were obtained by backcrossing between paternal B. oleracea and maternal semi-fertile F1 plants. Genomic in situ hybridization (GISH) combined with dual-colour fluorescence in situ hybridization (dcFISH) showed that sterile F1 plants contained 21 chromosomes consisting of one B. oleracea chromosome set and one S. alba chromosome set, belonging to expected hybrids, and semi-fertile F1 plants contained 30 chromosomes consisting of two B. oleracea chromosome sets and one S. alba chromosome set. It is obvious that the semi-fertile F1 plants belong to unexpected hybrids. 1–3 trivalents were detected at meiotic metaphase I of semi-fertile F1 pollen mother cells (PMCs). Different separation ratios of S chromosomes were detected at anaphase I. A monosomic alien addition line (MAAL) was identified by GISH-dcFISH from BC1 plants; it contained 19 chromosomes consisting of 18 C chromosomes and 1 S chromosome. At meiotic metaphase I, 9 divalents from B. oleracea and one univalent from S. alba could be detected. Sometimes, one putative C-S trivalent could also be detected. The achievement of B. oleracea-S. alba monosomic alien addition lines lays a foundation for gene introgression, location and cloning.

Molecular and cytogenetic characterization of an Oryza officinalis–O. sativa chromosome 4 addition line and its progenies

The wild species Oryza officinalis Wall. ex Watt (2n = 24, CC) is a valuable genetic resource for rice (O. sativa L., 2n = 24, AA) breeding and genomics research. Genomic in situ hybridization (GISH) and molecular approaches were used to determine the nature and composition of the additional chromosome in a monosomic alien addition line (MAAL) of O. officinalis and its backcross progenies. The extra wild species chromosome in the MAAL (2n = 2x = 25) was a mosaic one, comprising of the long arm of chromosome 4 from O. officinalis and the short arm from O. sativa. Comparative analysis showed that O. sativa and O. officinalis shared high synteny of restriction fragment length polymorphism (RFLP) markers and low synteny of simple sequence repeat (SSR) markers. A DNA methylation alteration was revealed at C619 in the MAAL and progenies. Analysis of progenies of the MAAL indicated that introgression segments were small in size and introgression was not evenly distributed along the long arm. One recombination hot spot between C513 and RG177 was identified, which is in a gene-rich region.

Behaviour of Sinapis alba chromosomes in a Brassica napus background revealed by genomic in-situ hybridization

Genomic in-situ hybridization (GISH) was applied to study the behaviour of addition chromosomes in first and second backcross (BC) progenies of hybrids between Brassica napus ssp. napus L. (AACC, 2n = 38) and Sinapis alba L. (SS, 2n = 24) produced by electrofusion. With GISH using genomic DNA of S. alba was used as probe it was possible to clearly distinguish both of the parental genomes and effectively monitor the fate of S. alba chromosomes in the BC(1) and BC(2) progenies. GISH analysis confirmed the sesquidiploid genome composition (AACCS) of the BC(1) progenies, which contained 38 chromosomes from B. napus and 12 chromosomes from S. alba. Genome painting in the pollen mother cells (PMCs) of the BC(1) plants revealed intergenomic association between B. napus and S. alba chromosomes, whereby a maximum of 4 trivalents between AC and S chromosomes were identified at metaphase I. In the BC(2) progenies, aneuploids with different numbers of additional chromosomes from S. alba, ranging from 1 to 7, were confirmed. Three putative monosomic alien addition lines were characterized, and the results are discussed with respect to the potential for intergenomic chromosome recombination.

Production and characterization of a complete set of individual chromosome additions from Oryza officinalis to Oryza sativa using RFLP and GISH analyses

Monosomic alien addition lines (MAALs) are valuable materials for comparative analyses of two distinct genomes, for elucidating introgression mechanisms, and for dissecting genes controlling complex traits. In the study reported here, MAALs of rice containing the complete genome of Oryza sativa and individual chromosomes of Oryza officinalis were produced. Interspecific hybridizations were made between O. sativa L. ssp. Japonica (CV, Hejiang 19, 2 n = 24, AA) and O. officinalis (Acc. HY018, 2 n = 24, CC). Two backcrosses were made to the cultivated rice to obtain BC2F1 plants. Through RFLP and GISH analyses, 25 MAALs (2 n = 25, AA + 1C) were identified and divided into 12 syntenic groups, designated MAALs 1-12. MAALs 1, 2, 3, 5, 7 and 10 were each represented by one plant, MAALs 8, 11 and 12 by two plants, MAALs 6 and 9 by four plants, and MAAL 4 by five plants. An ideogram of the C-genome of O. officinalis was constructed, based on GISH analysis of the interspecific hybrid and the MAALs. Comparative RFLP maps showed strong syntenic associations between the A-genomes and C-genomes. Chromosomal arrangements such as translocations and duplications were detected in different alien chromosomes of the MAALs. The complete set of O. officinalis MAALs generated here provides a novel manipulation platform for exploiting and utilizing the O. officinalis genome and carrying out genetic studies.

Morphological and molecular characterization of twoG. somalense monosomic alien addition lines (MAALs)

TwoG. somalense monosomic alien addition lines were identified from the derived backcross progenies of allohexaploid betweenG. hirsutum andG. somalense through cytological and morphological observation. Furthermore, the alien addition chromosome was identified and distinguished by RAPD analysis. A total of 160 RAPD primers were used for PCR amplification. Primer SBSG11 could produce a specific molecular marker (600 bp) for monosomic alien addition line I (MAAL I). Primer SBSC03 could produce a specific molecular marker (700 bp) for monosomic alien addition line II(MAAL II). SBSE07 and SBSE08 could respectively produce common molecular marker for monosomic alien addition lines I and II.G. somalense alien addition lines could be important for cotton improvement.

Morphological and molecular characterization of two G. somalense monosomic alien addition lines (MAALs)

Morphological and molecular characterization of two G. somalense monosomic alien addition lines (MAALs)

Introduction of Australian Diploid Cotton Genetic Variation into Upland Cotton

Genetic barriers often prevent exploiting diploid cotton germplasm for the improvement of tetraploid cotton. The objective of this study was to investigate mating schemes to achieve introgression of Gossypium sturtianum J.H. Willis and G. australe F. Muell diploid cottons into tetraploid G. hirsutum L. Gossypium hirsutum × G. sturtianum and G. hirsutum × G. australe hexaploids were backcrossed to G. hirsutum to produce BC1 pentaploids and BC2 and BC1S1 euploid and aneuploid plants. The use of G. hirsutum × G. australe pentaploids as male parent in backcrosses with G. hirsutum allowed the production of an important progeny of BC2 self fertile plants that were euploid or carried one chromosome of G. australe in addition to the 52 chromosomes of G. hirsutum The only two BC2 fertile plants issued from G. hirsutum × G. sturtianum hybrids were monosomic addition materials. Both of them were obtained with the pentaploid as female parent in the backcross to cv. Stam F. These results confirm that cotton male gametes are more limited than female gametes in the number of supernumerary chromosomes they can carry. This provides a means of developing alien monosomic addition lines in the G. hirsutum background from all the diploid species of Gossypium whose chromosomes do not carry genes preventing their individual male transfer. The analysis of the monosomic addition plants produced from the G. hirsutum × G. australe hexaploid with simple sequence repeat (SSR) markers allowed us to distinguish seven lines carrying different single chromosomes of G. australe These lines constitute valuable materials with which to carry out fundamental and applied genetic investigations.

Chromosome pairing in haploid plants of radish derived from alien monosomic addition lines

AbstractSix haploid plants of radish were obtained via alien monosomic addition lines (2n = 19). One plant was derived from anther culture of an Raphanus sativus‐Brassica oleracea addition line, one plant from the selected smaller seed of an R. sativus‐Sinapis arvensis addition line and four plants from an R. sativus‐B. rapa addition line. During metaphase I of pollen mother cells, two plants exhibited the chromosome pairing of (0‐3)II+ (3‐9)I, three showed (0‐1)III + (0‐3)II + (3‐9)I and the remaining plant (0‐2)II + (5‐9)I. Trivalents seemed to be formed by the pairing between two larger chromosomes and the smaller one with somewhat loose pairing. All haploid plants were inferior to the radish cv. ‘Shogoin’ (2n = 18) with respect to vegetative growth. Their flowers were smaller, with sterile pollen grains, but a few normal flowers with fertile pollen sporadically developed and then produced a few seeds. It is suggested that the radish genome (R, n = 9) might comprise three pairs of homoeologous chromosomes, with the remaining three chromosomes carrying the homologous region(s) that results in a trivalent formation.

Transmission and recombination of homeologous Solanum sitiens chromosomes in tomato.

The goal of the present experiments was to transfer the chromosomes of Solanum sitiens (syn. Solanum rickii) into cultivated tomato ( Lycopersicon esculentum). By crossing an allotetraploid L. esculentum x Solanum sitiens hybrid to sesquidiploid L. esculentum x S. lycopersicoides, a trigenomic hybrid (2n+14=38) was obtained. Analysis of the latter by GISH (genomic in situ hybridization) indicated it contained a full set of 12 S. sitiens chromosomes, plus two extras from S. lycopersicoides. This and other complex hybrids were pollinated with Lycopersicon pennellii-derived bridging lines to overcome unilateral incompatibility. A total of 40 progeny were recovered by embryo rescue, including diploids and aneuploids (up to 2n+8). In order to determine the origin of chromosomes and the location of introgressed segments, progeny were genotyped with RFLP markers. S. sitiens-specific markers on all chromosomes, except 6 and 11, were detected in the progeny. Several S. sitiens chromosomes were transmitted intact, either through chromosome addition (i.e., trisomics) or substitution (i.e., disomics). Recombination between S. sitiens and L. esculentum was detected on most chromosomes, in both diploid and aneuploid progeny. A monosomic alien addition line for S. sitiens chromosome 8 was identified, and the extra chromosome was stably transmitted to approximately 13% of the backcross progeny. This study demonstrates the feasibility of gene transfer from S. sitiens to L. esculentum through chromosome addition, substitution, and recombination in the progeny of complex aneuploid hybrids.

A genetic linkage map of Nicotiana plumbaginifolia/ Nicotiana longiflora based on RFLP and RAPD markers

We have constructed a genetic linkage map for Nicotiana plumbaginifolia/Nicotiana longiflora (2n= 2x=20), based on the segregation of 69 RFLP and 102 RAPD loci in 99 F2 plants from the cross N. plumbaginifolia×N. longiflora. The map consists of nine major linkage groups, each containing more than nine marker loci, and spans 1062 cM. Twenty of the RFLP markers were mapped previously to Nicotiana sylvestris (2n=2x=24) chromosomes using monosomic alien addition lines. Taxonomically, N. plumbaginifolia and N. sylvestris belong to the same section, namely the Alatae; however, cytogenetic evidence indicates that they are not closely related. Comparison of the distribution of markers common to both maps suggests that genome reorganization has occurred during the evolution of these two species. Evidence is also presented that genome reorganization may be accompanied by gain and loss of specific classes of DNA sequences in their genomes.

Interspecific chromosomal rearrangements in monosomic addition lines of Allium

Monosomic alien addition lines (MAALs) are useful for assigning linkage groups to chromosomes. We examined whether the chromosomal rearrangements following the introduction of a single onion (Allium cepa) chromosome into the Allium fistulosum genome were produced by homeologous crossing over or by a nonreciprocal conversion event. Among the monosomic lines available, 17 were studied by fluorescent genomic in situ hybridisation, using total A. cepa genomic DNA as the probe and total A. fistulosum genomic DNA as the competitor. In this way, rearrangements such as chromosomal translocations between A. cepa and A. fistulosum were identified as terminal regions consisting of tandem DNA repeats. Homeologous crossing over between the two closely related genomes occurred in 4 of the 17 lines, suggesting that such events are not rare. On the basis of a detailed molecular cytogenetic characterisation, we identified true monosomic alien addition lines for A. cepa chromosomes 3, 4, 5, 7, and 8 that can reliably be used in genetic studies.

Introgression of isozyme genes utilizing monosomic alien addition lines (MAALs) of Oryza officinalis in O. sativa

Starch gel electrophoresis was carried out on ten monosomic alien addition lines (MAALs) of Oryza officinalis (CC genome) in O. sativa (AA genome) at Punjab Agricultural University, Ludhiana, India during 1993–1995. The diploid progeny from MAALs were studied for possible gene transfer of isozyme genes. Analysis showed introgression for alleles of wild species for peroxidase, esterase and acid phosphatase isozymes in progeny of MAAL 2, esterase in MAAL 7 and acid phosphatase in MAAL 6, indicating partial homology between the two genomes. MAAL 2 yielded the highest number of recombinants. The potential of addition lines for alien gene transfer as well as for linkage mapping is discussed.