Assignment of unanchored scaffolds in genome of Brassica napus by RNA-seq analysis in a complete set of Brassica rapa-Brassica oleracea monosomic addition lines

The economically valuable oil crop Brassica napus(AACC,2 n=38),which arose from interspecific hybridization between the diploid ancestors Brassica rapa(AA,2 n=20) and Brassica oleracea(CC,2 n=18),has a complex genome.More than 10% of the assembled sequences,most of which belong to the C subgenome,have not been anchored to the corresponding chromosome.Previously,a complete set of monosomic alien addition lines(MAALs,C1–C9) with each of the nine C-subgenome chromosomes added to the extracted A subgenome was obtained from the allotetraploid B.napus donor Oro,after the ancestral B.rapa(RBR Oro) genome was restored.These MAALs effectively reduced the complexity of the B.napus genome.Here,we determined the expression values of genes on unanchored scaffolds in the MAALs and RBR Oro.Then,multiple comparisons of these gene expression values were used to determine the affiliations of the nonanchored scaffolds on which the genes were located.In total,54.68%(44.11 Mb) of the 80.67 Mb of non-anchored scaffolds belonging to the C subgenome were assigned to corresponding C chromosomes.This work highlights the potential value of these MAALs in improving the genome quality of B.napus.

The Meiotic Behavior of an Alien Chromosome in Triticum aestivum-Haynaldia villosa Monosomic Addition Lines

By the combination of cytological analysis and using genomic in situ hybridization technique to identify an alien chromosome in wheat-Haynaldia villosa monosomic addition lines, we studied the meiotic behavior of the alien chromosome. The results indicated that the frequency of bivalent pairing was lower than the value expected in PMCs of two monosomic addition lines, the frequency of wheat chromosomes unpairing increased, and the wheat homologous chromosome pairing was interfered with by the added chromosome 6V at metaphase I. The chromosome 6V lagged in 20.3% -29.3% of PMCs, sister chromatids 6V early divided in 29.0% - 34.1% of PMCs, the single chromosome 6V in 18.2% - 26.1% of PMCs went to a pole randomly, the breakage frequency of chromosome 6V was 1.2% - 2.9%. Meanwhile, it was also found that several wheat chromosomes showed earlier division, lagging and breakage in a few PMCs. It revealed that the added chromosome 6V influenced the behavior of wheat chromosomes at anaphase. It was also found that the translo-cation was produced between 6V and wheat chromosomes in 1.2% of PMCs. It offered evidence for transloca-tion between wheat and Haynaldia villosa 6V chromosomes.

Morphological characteristics and identification of new monosomic stocks for cotton (Gossypium hirsutum L.)

The presence of distinct morphological markers in monosomics is important for selection and maintenance of the monosomic plants in subsequent generations and for a well-targeted chromosome substitutions. Here we present cytological and morphological features of the cotton (Gossypium hirsutum L.) monosomic lines developed in Uzbekistan, and their identification by means of translocation tests. We report “reduced” stigma as a new phenotypic marker for cotton monosomics, which makes it possible to distinguish cytotypes without cytological analyses. We identified eleven cotton monosomes by translocation tests using our 28 translocation cotton lines. We determined such features of the cotton monosomic lines as significant lowering of the pollen fertility, genetic determination of variation in pollen fertility in different flowers of the same monosomic plants and variation of both meiotic index and tetrads with micronuclei in different buds. New features of cotton monosomic lines, described herein, should be useful for future cotton genome investigation and development of new chromosome substitution lines.

Development of New Interspecific Monosomic F_1 Substitution Stocks for Investigations in Cotton Genome

As it is known a complete coverage of cotton(Gossypium hirsutum L.) genome with hypoaneuploids is not still realized.Therefore the detection of new types of aneuploids especially in different cytogenetic collections is very useful.In Uzbekistan,long-term investigations towards development

Creating Wheat Germplasm for High Quality Breeding by Monosomic Backcrossing

By crossing bread wheat cultlvar GC8901 with the 1D monosonlc line of Xiaoyan No. 6 and backcrosslng the offsprlng with the Xlaoyan No. 6 1D monosonlc llne for 5 years, high-molecular-welght glutenin subunlts 1Dx5＋1Dy10 from GC8901 have been transferred Into wheat cultivar Xiaoyan No. 6. The BC5F1 offspring lines had been detected by using methods of cytology, marker, molecular marker and six elite single plants with high molecular-welght glutenin subunlts： lAx1, 1Bx14＋1 By15, 1Dx5＋1 Dy10 were Identified. Those lines have high-yleld potential with better agronomic characters and have been used In high quality wheat breeding processes as well.

Glucosinolates in Self-crossed Progenies of Monosomic Cabbage Alien Addition Lines in Chinese Cabbage

Brassica species have been reported to possess cancer preventive activity due to glucosinolates(GLS) and their derived properties. Many studies on GLS have focused on Brassica oleracea and Brassica rapa. However, information on GLS in progeny between Chinese cabbage(B. rapa ssp. pekinensis) and cabbage(B. oleracea var. capitata) remains limited. In this study, eight GLS were detected in the self-crossed progenies of monosomic cabbage alien addition lines in Chinese cabbage(Chinese cabbage–cabbage MAALs) and parental Chinese cabbage, and nine GLS were detected in the parental cabbage. The variation of GLS content ranges was greater in the progeny than in the parental Chinese cabbage. The nine GLS identified were subjected to PCA to evaluate the differences among progeny and parents. Eight progeny samples had a comprehensive principal component score closer to or greater than that of cabbage, and four of them exhibited glucoraphanin(GRA) and total GLS contents greater than that of Chinese cabbage with the relative content of total indolic GLS was greater than 50%. These results offered new opportunity to improve GLS-containing of Chinese cabbage using genes from cabbage.

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.

Evaluation of Aegilops tauschii for Heading Date and Its Gene Location in a Re-synthesized Hexaploid Wheat

The successful worldwide cultivation of hexaploid wheat in a diverse range of environments is because of, in part, breeding and selection for appropriate heading date. To adjust and fine-tune the heading time of hexaploid wheat to particular geographical regions and specific environment within these, there is an urgent need to evaluate and use alternative alleles for heading time. Aegilops tauschii, the donor species of D-genome of hexaploid wheat, has a wide geographic distribution. The present study revealed a wide variation for heading time among 56 Ae. tauschii accessions. All the accessions with short heading dates belonged to the ssp. tauschii, whereas most of ssp. strangulata accessions showed very long heading date. The heading date was also related to distribution of this species. The monotelosomic and monosomic analysis of a synthetic hexaploid wheat showed that chromosome 2D derived from ssp. tauschii accession AS60 had a major effect on promoting heading time with a reduction of more than 5 days. It is postulated that this Ae. tauschii genotype possess the allele Ppd-D^t1 responsible for the insensitivity to photoperiod. This allele is probably different from Ppd-D1 existing in hexaploid wheat. The new allele Ppd-D^t1 derived from Ae. tauschii might be used as a source for hexaploid wheat breeding on photoperiod response.

Cytogentic and prognostic characteristic of acute myeloid leukemia with monosomal karyotype

Objective To explore the cytogenetic and prognostic significance of monosomal karyotype(MK)in adult patients with acute myeloid leukemia(AML).Methods From September 2002 to Nevember 2014 in Blood Diseases Hospital,Chinese Academy of Medical Sciences,97Cases with AML were enrolled,including 96 cases