In order to develop more wheat-Haynaldia villosa translocations involving different chromosomes and chromosome segments of H. villosa, T. durum-H, villosa amphiploid was irradiated with ^60Co γ-rays at doses of 800, ...In order to develop more wheat-Haynaldia villosa translocations involving different chromosomes and chromosome segments of H. villosa, T. durum-H, villosa amphiploid was irradiated with ^60Co γ-rays at doses of 800, 1,200, and 1,600 rad. Pollen collected from the spikes 1, 2, and 3 days after irradiation were transferred to emasculated spikes of the common wheat cv. ‘Chinese Spring＇. Genomic in situ hybridization was used to identify wheat-H, villosa chromosome translocations in the M1 generation. Transmission of the identified translocation chromosomes was analyzed in the BC1, BC2, and BC3 generations. The results indicated that all three irradiation doses were highly efficient for inducing wheat-alien translocations without affecting the viability of the M1 seeds. Within the range of 800-1,600 rad, both the efficiency of translocation induction and the frequency of interstitial chromosome breakage-fusion increased as the irradiation dosage increased. A higher translocation induction frequency was observed using pollen collected from the spikes 1 day after irradiation over that of 2 or 3 days after irradiation. More than 70% of the translocations detected in the M1 generation were transmitted to the BC1 through the female gametes. All translocations recovered in the BC1 generation were recovered in the following BC2, and BC3 generations. The transmission ability of different translocation types in different genetic backgrounds showed an order of ‘whole-arm translocation 〉 small alien segment translocation 〉 large alien segment translocation＇, through either male or female gametes, In general, the transmission ability through the female gametes was higher than that through the male gametes. By this approach, 14 translocation lines that involved different H. villosa chromosomes have been identified in the BC3 using EST-STS markers, and eight of them were homozygous.展开更多
Haynaldia villosa possesses a lot of important agronomic traits and has been a powerful gene resource for wheat improvement. However, only several wheat-H, villosa translocation lines have been reported so far. In thi...Haynaldia villosa possesses a lot of important agronomic traits and has been a powerful gene resource for wheat improvement. However, only several wheat-H, villosa translocation lines have been reported so far. In this study, we attempted to develop an efficient method for inducing wheat-H, villosa chromosomal translocations. Triticum durum- Haynaldia villosa amphiploid pollen treated with 1 200 rad ^60Co-y-rays was pollinated to Triticum aestivum cv. ＇Chinese Spring＇. Ninety-eight intergeneric translocated chromosomes between T. durum and H. villosa were detected by genomic in situ hybridization in 44 of 61 M1 plants, indicating a translocation occurrence frequency of 72.1%; much higher than ever reported. There were 26, 62 and 10 translocated chromosomes involving whole arm translocations, terminal translocations, and intercarlary translocations, respectively. Of the total 108 breakage-fusion events, 79 involved interstitial regions and 29 involved centric regions. The ratio of small segment terminal translocations （W.W-V） was much higher than that of large segment terminal translocations （W-V.V）. All of the M1 plants were self-sterile, and their backcross progeny was all obtained with ＇Chinese Spring＇ as pollen donors. Transmission analysis showed that most of the translocations were transmittable. This study provides a new strategy for rapid mass production of wheat-alien chromosomal translocations, especially terminal translocations that will be more significant for wheat improvement.展开更多
Haynaldia villosa Schur. (syn. Dasypyrum villosum Candargy, 2n=14, VV) has been proved to be an important genetic resource for wheat improvement. The development of translocation with small alien chromosome segments, ...Haynaldia villosa Schur. (syn. Dasypyrum villosum Candargy, 2n=14, VV) has been proved to be an important genetic resource for wheat improvement. The development of translocation with small alien chromosome segments, especially interstitial translocation, will be helpful for better utilization of its useful genes. Up to now, most of the reported Triticum aestivum – H. villosa translocation lines are involved in a whole arm or large alien fragments. In this paper, we report a highly efficient approach for the creation of small chromosome segment translocation lines. Before flowering, the female gametes of wheat-H. villosa 6VS/6AL translocation line were irradiated by 60CO-γ ray at 160 Rad/M dosage rate and three dosages (1600, 1920, 2240 Rad). Anthers were removed from the irradiated florets on the same day and the florets were pollinated with normal fresh pollens of T. aestivum cv. Chinese Spring after 2-3 days. Genomic in situ hybridization (GISH) at mitosis metaphase of root-tip cell of M1 plants was used to detect the chromosome structural changes involving 6VS of H. villosa. Among the 534 M1 plants screened, 97 plants contained small segment chromosome structural changes of 6VS, including 80 interstitial translocation chromosomes, 57 terminal translocation chromosomes and 55 deletion chromosomes. For the 2240 Rad dosage treatment, the inducement frequencies of interstitial translo-cation, terminal translocation and deletion were 21.02%, 14.01%, and 14.65%, respectively, which were much higher than those previously reported. The M2 seeds were obtained by backcrossing of 74 M1 plants involving 146 chromosomes structural changes of 6VS, and it was found that the structural aberrations in the M1 plants could be transmitted to their progenies. Irradiating mature female gametes of whole arm translocation is a new and highly efficient approach for creation of small segment chromosome struc-tural changes, especially for interstitial translocations.展开更多
To Investigate the mechanism of resistance to wheat （Triticum aestivum L.） powdery mildew, suppression subtractlve hybridization was conducted between an isogenic resistant line carrying Pm21 and its recurrent paren...To Investigate the mechanism of resistance to wheat （Triticum aestivum L.） powdery mildew, suppression subtractlve hybridization was conducted between an isogenic resistant line carrying Pm21 and its recurrent parent Yangmal 5 to Isolate the resistance relative genes. A cDNA fragment specifically expressed in the resistant line was obtained and its full length was cloned by in silico cloning and RT-PCR. This gene encoded a deduced protein of 219 amino acids with a leucine-rich repeat （LRR） motif, often found In plant resistance genes, and was designated as Ta-LRR2. Ta-LRR2 had an increased expression level in the resistant line after Inoculation with Erysiphe graminis DC. f. sp. tritici Marchal. PCR analysis with different cytogenetlc stocks suggested that Ta-LRR2 was specifically associated with chromosome arms 6VS and 6AS. Linkage analysis further showed that Ta-LRR2 could be used as a resistance gene analog polymorphism marker of Pm21 for marker-assisted selection in germplasm enhancement and breeding practice. Moreover, how to Isolate Pm21 based on the Information obtained for Ta-LRR2 is discussed.展开更多
基金supported by the National Natural Science Foundation of China (No.30270827 and 30871519)the High Tech Program of China (No.2006AA100101,2006AA10Z1F6)the Ministry of Educate 111 Project (B08025)
文摘In order to develop more wheat-Haynaldia villosa translocations involving different chromosomes and chromosome segments of H. villosa, T. durum-H, villosa amphiploid was irradiated with ^60Co γ-rays at doses of 800, 1,200, and 1,600 rad. Pollen collected from the spikes 1, 2, and 3 days after irradiation were transferred to emasculated spikes of the common wheat cv. ‘Chinese Spring＇. Genomic in situ hybridization was used to identify wheat-H, villosa chromosome translocations in the M1 generation. Transmission of the identified translocation chromosomes was analyzed in the BC1, BC2, and BC3 generations. The results indicated that all three irradiation doses were highly efficient for inducing wheat-alien translocations without affecting the viability of the M1 seeds. Within the range of 800-1,600 rad, both the efficiency of translocation induction and the frequency of interstitial chromosome breakage-fusion increased as the irradiation dosage increased. A higher translocation induction frequency was observed using pollen collected from the spikes 1 day after irradiation over that of 2 or 3 days after irradiation. More than 70% of the translocations detected in the M1 generation were transmitted to the BC1 through the female gametes. All translocations recovered in the BC1 generation were recovered in the following BC2, and BC3 generations. The transmission ability of different translocation types in different genetic backgrounds showed an order of ‘whole-arm translocation 〉 small alien segment translocation 〉 large alien segment translocation＇, through either male or female gametes, In general, the transmission ability through the female gametes was higher than that through the male gametes. By this approach, 14 translocation lines that involved different H. villosa chromosomes have been identified in the BC3 using EST-STS markers, and eight of them were homozygous.
基金Supported by the National Natural Science Foundation of China(30270827)the Program for Changjiang Scholars and Innovative Research in Universities(10418).
文摘Haynaldia villosa possesses a lot of important agronomic traits and has been a powerful gene resource for wheat improvement. However, only several wheat-H, villosa translocation lines have been reported so far. In this study, we attempted to develop an efficient method for inducing wheat-H, villosa chromosomal translocations. Triticum durum- Haynaldia villosa amphiploid pollen treated with 1 200 rad ^60Co-y-rays was pollinated to Triticum aestivum cv. ＇Chinese Spring＇. Ninety-eight intergeneric translocated chromosomes between T. durum and H. villosa were detected by genomic in situ hybridization in 44 of 61 M1 plants, indicating a translocation occurrence frequency of 72.1%; much higher than ever reported. There were 26, 62 and 10 translocated chromosomes involving whole arm translocations, terminal translocations, and intercarlary translocations, respectively. Of the total 108 breakage-fusion events, 79 involved interstitial regions and 29 involved centric regions. The ratio of small segment terminal translocations （W.W-V） was much higher than that of large segment terminal translocations （W-V.V）. All of the M1 plants were self-sterile, and their backcross progeny was all obtained with ＇Chinese Spring＇ as pollen donors. Transmission analysis showed that most of the translocations were transmittable. This study provides a new strategy for rapid mass production of wheat-alien chromosomal translocations, especially terminal translocations that will be more significant for wheat improvement.
基金the National Natural Science Foundation of China (Grant No. 30270827)Project of Higher Education for Innovation and Introduction of Resourcefullness (111 Project) (Grant No. B08025)
文摘Haynaldia villosa Schur. (syn. Dasypyrum villosum Candargy, 2n=14, VV) has been proved to be an important genetic resource for wheat improvement. The development of translocation with small alien chromosome segments, especially interstitial translocation, will be helpful for better utilization of its useful genes. Up to now, most of the reported Triticum aestivum – H. villosa translocation lines are involved in a whole arm or large alien fragments. In this paper, we report a highly efficient approach for the creation of small chromosome segment translocation lines. Before flowering, the female gametes of wheat-H. villosa 6VS/6AL translocation line were irradiated by 60CO-γ ray at 160 Rad/M dosage rate and three dosages (1600, 1920, 2240 Rad). Anthers were removed from the irradiated florets on the same day and the florets were pollinated with normal fresh pollens of T. aestivum cv. Chinese Spring after 2-3 days. Genomic in situ hybridization (GISH) at mitosis metaphase of root-tip cell of M1 plants was used to detect the chromosome structural changes involving 6VS of H. villosa. Among the 534 M1 plants screened, 97 plants contained small segment chromosome structural changes of 6VS, including 80 interstitial translocation chromosomes, 57 terminal translocation chromosomes and 55 deletion chromosomes. For the 2240 Rad dosage treatment, the inducement frequencies of interstitial translo-cation, terminal translocation and deletion were 21.02%, 14.01%, and 14.65%, respectively, which were much higher than those previously reported. The M2 seeds were obtained by backcrossing of 74 M1 plants involving 146 chromosomes structural changes of 6VS, and it was found that the structural aberrations in the M1 plants could be transmitted to their progenies. Irradiating mature female gametes of whole arm translocation is a new and highly efficient approach for creation of small segment chromosome struc-tural changes, especially for interstitial translocations.
基金Supported by the Hi-Tech Research and Development(863) Program of China(2001 AA222152,2003AA207100,and 2004AA222140)the National Natural Science Foundation of China and the Program for Changjiang Scholars and Innovative Research Team in University
文摘To Investigate the mechanism of resistance to wheat （Triticum aestivum L.） powdery mildew, suppression subtractlve hybridization was conducted between an isogenic resistant line carrying Pm21 and its recurrent parent Yangmal 5 to Isolate the resistance relative genes. A cDNA fragment specifically expressed in the resistant line was obtained and its full length was cloned by in silico cloning and RT-PCR. This gene encoded a deduced protein of 219 amino acids with a leucine-rich repeat （LRR） motif, often found In plant resistance genes, and was designated as Ta-LRR2. Ta-LRR2 had an increased expression level in the resistant line after Inoculation with Erysiphe graminis DC. f. sp. tritici Marchal. PCR analysis with different cytogenetlc stocks suggested that Ta-LRR2 was specifically associated with chromosome arms 6VS and 6AS. Linkage analysis further showed that Ta-LRR2 could be used as a resistance gene analog polymorphism marker of Pm21 for marker-assisted selection in germplasm enhancement and breeding practice. Moreover, how to Isolate Pm21 based on the Information obtained for Ta-LRR2 is discussed.
