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Octoploid triticale were derived from common wheat (Triticum aestivum L. 'Mianyang11') x rye (Secale cereale L. 'Kustro'), and some progeny were obtained by the backcrossing of triticale with 'Mianyang11' followed by self-fertilization. In situ hybridization using rye genomic DNA and repetitive sequences pAs1 and pSc119.2 as probes was used to analyze the mitotic chromosomes of these progeny. Three wheat-rye 1R monosomic addition lines and a wheat line (12FT-1685) containing a 1R and a 1BL.1RS translocation chromosome were identified. Abnormal mitosis was observed in the two lines. During mitosis of a 1R monosomic addition line (3-8-20-1R-2), lagging chromosomes, micronuclei, chromosomal bridges, and the one pole segregation of 1R chromosome were observed. Abnormal mitotic behaviour of chromosomes was also observed in some of the self-progeny plants of lines 12FT-1685 and 3-8-20-1R-2. These progeny contained 1R chromosome or 1R chromosome arm. In addition, 4B chromosomes were absent from one of the progeny of 3-8-20-1R-2. This abnormal mitotic behaviour of chromosomes was not observed in two other 1R monosomic addition lines. These results indicate that a single 1R chromosome added to wheat might cause abnormal mitotic behaviour of both wheat and rye chromosomes and different genetic variations might occurr among the sibling 1R monosomic addition lines. Key words: abnormal mitotic behaviour, monosomic addition line, wheat, rye. Des triticales octoploides ont ete derives du croisement entre le ble tendre (Triticum aestivum L. 'Mianyang11') et le seigle (Secale cereale L. 'Krusto'), tandis que d'autres ont ete obtenus au terme d'un retrocroisement des triticales avec 'Mianyang11' et d'une autofecondation. Des hybridations in situ a l'aide de sondes composees de l'ADN genomique du seigle ou des sequences repetees pAs1 et pSc119.2 ont ete realisees pour analyser le comportement des chromosomes mitotiques chez ces plantes. Les auteurs ont identifie trois lignees d'addition monosomique ble-seigle 1R et une lignee de ble (12FT-1685) contenant le 1R et une translocation 1BL.1RS. Des mitoses anormales ont ete observees chez les deux lignees. Au cours de la mitose chez une lignee d'addition monosomique 1R (3-8-20-1R-2), des chromosomes retardataires, des micronoyaux, des ponts chromosomiques et une segregation unipolaire du chromosome 1R ont ete observes. Un comportement mitotique anormal des chromosomes a egalement ete observe chez certains descendants de l'autofecondation des lignees 12FT-1685 et 3-8-20-1R-2. Ces progenitures contenaient le chromosome 1R ou un bras 1R. De plus, les chromosomes 4B etaient absents chez l'un des descendants de 3-8-20-1R-2. Ce comportement mitotique anormal des chromosomes n'a pas ete observe chez deux autres lignees d'addition monosomique 1R. Ces resultats indiquent que l'addition d'un seul chromosome 1R au genome du ble peut causer un comportement mitotique anormal tant des chromosomes du ble que du seigle et que differents changements genetiques peuvent survenir parmi des lignees d'addition monosomique 1R sceurs. [Traduit par la Redaction] Mots-cles: comportement mitotique anormal, lignee d'addition monosomique, ble, seigle., Introduction Wide hybridization is one of the stresses that might trigger reorganization of parental genomes (McClintock 1978) and has been widely used in cereal breeding programs (Feuillet et al. 2008; [...]

Along challenging against life-threaten from various viruses for instance avian flu, AIDS, SARS, ect., and enjoying the progresses of molecular biomedicine, it is the time for us to decipher the deep fact on virus origination and evolution. Virus is a non-cell organism existing between life and non-life. It shows a complete parasitic characteristic in its way of living. Concerning its origination and evolution, there are three different hypotheses. One is that virus was generated before cell on the earth of pre-biotic stage. As a former organism, it would evolutinate to prokaryotic cell and eukaryotic cell. The secondary is that both cell and virus were generated simultaneously in the pre-biotic stage. During evolution, virus developed its parasitism on cells. The third is that virus is a macromolecule or macromolecular complex, "being thrown out of cells". It came from cells and was parasitic to cells. Three hypotheses address that eventuaUy, virus evolutinated its complete parasitic style of living. Although the most of biologists believed the third hypothesis previously, they are paying their most attention to aH these hypotheses nowadays regarding the proceedings of medical molecular biology. Both proceedings of molecular biology and natural philosophy show that the understanding to the pluralism of virus origination would be the most credible solution to assure the position of virus on the evolution tree on the earth, which accomplished the central dogma of molecular biology. [ABSTRACT FROM AUTHOR]

Hexaploid triticale is an important genetic resource for genetic improvement of common wheat, which can broaden the genetic basis of wheat. In order to lay a foundation for the subsequent research and utilization of triticale germplasm materials, the chromosomal genetic characteristics of cross and backcross offspring of hexaploid triticale×hexaploid wheat were investigated in the process of transferring rye chromatin from hexaploid triticale to hexaploid wheat. Hybrid and backcross combinations were prepared with hexaploid triticale 16yin171 as the maternal parent and hexaploid wheat Chuanmai62 as the paternal parent. The chromosomes in root tip cells of F 1 , BC 1 F 1 and BC 1 F 2 plants were traced and identified non-denaturing florescence in situ hybridization (ND-FISH). The results indicated that the backcross setting rate of hybrid F 1 was 2.61%. The transmission frequency of 2R chromosome was the highest in BC 1 F 1 plants while the transmissibility of rye chromosome in BC 1 F 2 plant was 6R>4R>2R, and the 5B-7B wheat translocation in BC 1 F 2 plants showed severe segregation. A total of 24 structural variant chromosomes were observed both in BC 1 F 1 and BC 1 F 2 plants, including chromosome fragments, isochromosomes, translocations, and dicentric chromosomes. In addition, the seed length and 1000-grain weight of some BC 1 F 2 plants were better than that of the hexaploid wheat parent Chuanmai 62. Therefore, multiple backcrosses should be adopted as far as possible to make the rapid recovery of group D chromosomes, ensuring the recovery of fertility in offspring, when hexaploid tritriale is used as a bridge to introduce rye genetic material into common wheat. At the same time, the potential application value of chromosomal structural variation materials should be also concerned.

Variety pedigree contains a lot of information, including parental origin, breeding methods, genetic relationship, and so on. Studying them could reveal the evolution characteristics and rules of breeding and ultimately guide practice. The pedigrees of 326 wheat varieties from 1936 to 2017 in the history of the Sichuan Province was collected and analyzed in terms of breeding methods, parental composition, changes of high frequency parents and backbone parents, genetic contribution, distribution of translocation lines and synthetic germplasms. Over the past 80 years since 1930s, breeders have selected 387 direct parents from a large number of materials, made 256 combinations by means of cross breeding, and have released 314 varieties from them, which contributed directly to wheat breeding and production in Sichuan. Wheat breeding experienced a process from utilizing landraces, introducing foreign germplasm to creating breeding materials independently; high-frequency parents and backbone parents used for breeding gradually changed in different stage of the breeding history. Synthetic germplasms contributed greatly to wheat breeding in recent years. The consistency of breeding objectives will inevitably lead to the loss of genetic diversity and the fragility of genetic basis. In the future, the protection and utilization of genetic resources should be strengthened. In this review, the development of wheat breeding in Sichuan was summarized through pedigree analysis, in order to provide a reference for future research.

Rye (Secale cereale L., RR) is a valuable genetic resource for the improvement of common wheat (Triticum aestivum L., AABBDD). Transferring alien rye genes into wheat by distant hybridization and automatic chromosome doubling is an important and efficient method to boost agronomic traits, disease resistance and widening the gene pool in wheat. In this study, an octoploid triticale CD-13 (AABBDDRR) was obtained via automatic chromosome doubling by crossing landrace Penganbaimaizi (T. aestivum L., AABBDD) and rye "Qinling rye" (S. cereale cv. Qinling, RR). GISH and FISH analyses indicated that CD-13 contained a 1RS-7DS.7DL wheat-rye small segment translocation chromosome. In order to transfer the 1RS-7DS small segment translocation into hexaploid wheat, 58 lines of the F5 inbred population from the cross CD-13 x Chuanmai 42 were screened for rye chromosome segments by GISH and FISH analyses. The results showed that 13 lines contained the 1RS-7DS.7DL small segment translocation chromosome by reciprocal translocation between 1RS and 7DS. These translocation lines carrying 1RS small rye alien segment were tested for the translocation breakpoints and the presence of a storage protein locus Sec-1. The Sec-1 locus was absent in the line 811, a stable 1RS-7DS.7DL small segment translocation line. The translocation breakpoint of 1RS-7DS.7DL of this line was located in the interval of IB267-IAG95 around the telomere of 1RS chromosome. Thousand-kernel weight of the line 811 was much higher than the parent CD-13, but not significantly different from Chuanmai 42. This indicated that 1RS-7DS.7DL small segment translocation had no negative effect on thousand-kernel weight in the genetic background of Chuanmai 42. The line with 1RS-7DS.7DL translocation chromosomes can be used as a new genetic material for further studies of valuable genes and their genetic effect on 1RS small segment.