小偃麦附加系Z1和Z2中外源染色体2Ai-2的结构组成

小偃麦附加系Z1和Z2中外源染色体2Ai-2的结构组成@张增燕$中国农业科学院作物育种栽培研究所!北京100081@辛志勇$中国农业科学院作物育种栽培研究所!北京100081@陈孝$中国农业科学院作物育种栽培研究所!北京100081小偃麦;;附加系;;染色体

Structural Organization of an Alien Group 2 Chromosome (2Ai-2)in Wheat-Thinopyum intermedium Addition Lines Z1 and Z2

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.