Barley yellow dwarf virus(BYDV),vectored by several aphid species,is the most significant viral pathogen of wheat and other grain cereals.Significant economic losses resulting from BYDV in wheat,barley and oats have b...Barley yellow dwarf virus(BYDV),vectored by several aphid species,is the most significant viral pathogen of wheat and other grain cereals.Significant economic losses resulting from BYDV in wheat,barley and oats have been reported in many countries.The most economic means of controlling BYDV is to develop wheat varieties with resistance to BYDV. So far no BYDV resistance has been described in wheat collections except one gene in some cultivars tolerant to BYDV. However, Thinopyrum intermedium ,two octoploids Zhong 4 awnless and TAF46,and the disomic addition lines,L1,Z1,Z2 and Z6 all showed resistance to BYDV. We developed several wheat Th.Intermedium translocation lines, Yw642, Yw443 and Yw243 etc., showing good BYDV resistance from L1 by inducing homologous pairing using CS Ph1 mutant. It was found that their BYDV resistance was controlled by a single dominant gene. Characterization of these wheat lines was carried out by GISH and RFLP analysis. The results of GISH showed that the lines, Yw642, Yw443 and Yw243 etc., were homozygous wheat Th.intermedium translocation lines containing 20 pairs of wheat chromosomes and 1 pair of wheat Th.intermedium translocation chromosomes,in which the chromosome segments of Th intermedium were transferred to the distal end of a pair of wheat chromosomes. RFLP analysis indicated that the translocation chromosome of the wheat lines was T7DS·7DL 7XL translocation. The breakpoint of translocation is located on the distal end of 7DL,between Xpsr965 and Xpsr680,about 90 99 cM from the centromere. The BYDV gene is located on the distal end of 7XL around Xpsr680,Xpsr687 and Xwg380.The RFLP markers of psr680,psr687 and wg380 co segregated with the BYDV resistance and could be used for marker assisted selection(MAS)in wheat breeding program for BYDV resistance.展开更多
The barley yellow dwarf virus(BYDV)resistance lines of Z1 and Z2 were derived from Zhong 5, a partial amphiploid resulted from the cross between Triticum aestivum (wheat) and Thinopyrum intermedium . Genomic in situ h...The barley yellow dwarf virus(BYDV)resistance lines of Z1 and Z2 were derived from Zhong 5, a partial amphiploid resulted from the cross between Triticum aestivum (wheat) and Thinopyrum intermedium . Genomic in situ hybridization (GISH) was used to analyze the chromosome constitution of Zhong 5 by using genomic DNA of Pseudoregneria strigosa (StSt,2 n =14)as the probe. The GISH results showed that zhong 5 contains 42 wheat chromosomes and l4 Th.intermedium chromosomes composed of 4 St, 4 Js,4 St J translocation and 2 St Js Robertsonian translocation chromosomes. The chromosome constitution of Z1 and Z2 was analyzed by GISH using genomic DNA probes from Th.intermedium and Ps.Strigosa . The GISH results indicated that both Z1 and Z2 possess 42 wheat chromosomes and 2 Th.intermedium chromosomes that were identical to a pair of St J translocation chromosomes in Zhong 5. The Th.intermedium chromosomes,designated as 2Ai 2 chromosome derived from Zhong 5,mostly belong to the St genome except the middle region (about one third of the long arm) belonging to the E(J)genome. A detailed RFLP analysis was conducted for Z1,Z2 and their parents,St and E (J) genomes. The results of RFLP analyses demonstrated that the Th.intermedium chromosomes(2Ai 2,St J)in Z1 and Z2 are extensively homologous to the Wheat group 2 chromosomes. The results of RFLP analyses on the genome composition of the 2Ai 2 chromosome were in agreement with the GISH results. Presence of psr 928 on 2AS and 2DS but absence on 2Ai 2S suggests some internal structural differences between 2Ai 2 and the wheat group 2 chromosomes. Some RFLP markers specific to the 2Ai 2 chromosome were identified and may be effectively used to select translocation lines with small segment of the 2Ai 2 chromosome and to localize the BYDV resistance gene in wheat background.展开更多
文摘Barley yellow dwarf virus(BYDV),vectored by several aphid species,is the most significant viral pathogen of wheat and other grain cereals.Significant economic losses resulting from BYDV in wheat,barley and oats have been reported in many countries.The most economic means of controlling BYDV is to develop wheat varieties with resistance to BYDV. So far no BYDV resistance has been described in wheat collections except one gene in some cultivars tolerant to BYDV. However, Thinopyrum intermedium ,two octoploids Zhong 4 awnless and TAF46,and the disomic addition lines,L1,Z1,Z2 and Z6 all showed resistance to BYDV. We developed several wheat Th.Intermedium translocation lines, Yw642, Yw443 and Yw243 etc., showing good BYDV resistance from L1 by inducing homologous pairing using CS Ph1 mutant. It was found that their BYDV resistance was controlled by a single dominant gene. Characterization of these wheat lines was carried out by GISH and RFLP analysis. The results of GISH showed that the lines, Yw642, Yw443 and Yw243 etc., were homozygous wheat Th.intermedium translocation lines containing 20 pairs of wheat chromosomes and 1 pair of wheat Th.intermedium translocation chromosomes,in which the chromosome segments of Th intermedium were transferred to the distal end of a pair of wheat chromosomes. RFLP analysis indicated that the translocation chromosome of the wheat lines was T7DS·7DL 7XL translocation. The breakpoint of translocation is located on the distal end of 7DL,between Xpsr965 and Xpsr680,about 90 99 cM from the centromere. The BYDV gene is located on the distal end of 7XL around Xpsr680,Xpsr687 and Xwg380.The RFLP markers of psr680,psr687 and wg380 co segregated with the BYDV resistance and could be used for marker assisted selection(MAS)in wheat breeding program for BYDV resistance.
文摘The barley yellow dwarf virus(BYDV)resistance lines of Z1 and Z2 were derived from Zhong 5, a partial amphiploid resulted from the cross between Triticum aestivum (wheat) and Thinopyrum intermedium . Genomic in situ hybridization (GISH) was used to analyze the chromosome constitution of Zhong 5 by using genomic DNA of Pseudoregneria strigosa (StSt,2 n =14)as the probe. The GISH results showed that zhong 5 contains 42 wheat chromosomes and l4 Th.intermedium chromosomes composed of 4 St, 4 Js,4 St J translocation and 2 St Js Robertsonian translocation chromosomes. The chromosome constitution of Z1 and Z2 was analyzed by GISH using genomic DNA probes from Th.intermedium and Ps.Strigosa . The GISH results indicated that both Z1 and Z2 possess 42 wheat chromosomes and 2 Th.intermedium chromosomes that were identical to a pair of St J translocation chromosomes in Zhong 5. The Th.intermedium chromosomes,designated as 2Ai 2 chromosome derived from Zhong 5,mostly belong to the St genome except the middle region (about one third of the long arm) belonging to the E(J)genome. A detailed RFLP analysis was conducted for Z1,Z2 and their parents,St and E (J) genomes. The results of RFLP analyses demonstrated that the Th.intermedium chromosomes(2Ai 2,St J)in Z1 and Z2 are extensively homologous to the Wheat group 2 chromosomes. The results of RFLP analyses on the genome composition of the 2Ai 2 chromosome were in agreement with the GISH results. Presence of psr 928 on 2AS and 2DS but absence on 2Ai 2S suggests some internal structural differences between 2Ai 2 and the wheat group 2 chromosomes. Some RFLP markers specific to the 2Ai 2 chromosome were identified and may be effectively used to select translocation lines with small segment of the 2Ai 2 chromosome and to localize the BYDV resistance gene in wheat background.
