Fine Identification And Genetic Analysis Of 5AL/6P Alien Transloction Lines Between Triticum Aestivum L. And Agropyron Cristatum (L.) Gaertn. By Molecular And Cytological Techniques

Agropyron cristatum (L.) Gaertn is a perennial cross-pollinate grass family and one of the important wild relatives of wheat, which possesses good resistance to cold,drought, saline-alkaline, powdery mildew, yellow dwarf,scab and rust disease of wheat. According to our previous researches, A.cristatum contained the genes conferring more tillers,superior numbers of florets and kernels per spike, which were from chromosome 6P. 4844-12 was a wheat-A. cristatum 6P disomic addition line, which produced from the hybridization between A.cristatum accession Z559 and T.aestivumcv.’Fukuhokomugi’ (AABBDD) by professor Lihui Li. The SM2-244 with superior numbers of florets and kernels per spike was one fragmental reciprocal translocation line identified by Luanyang, which was produced from the Fi hybridization between 4844-12 and’Gaocheng8901’by the ionizing radiation method. T. aestivumcv.’Gaocheng8901’is a high quality wheat with strong gluten. Some translocation lines of M6 and M7 progenies from SM2-244 were identified by Daicheng, and also 6P-specific molecular markers were developed. On this basis, the M8 and M9 progenies from SM2-244 were studied further and systematically in this article. Genomic in situ Hybridization (GISH), Fluorescence in situ Hybridization (FISH), molecular marker were carried out, and agronomic traits were evaluated from different years as replication.The results were as follows:1. Forty-three translocation lines were identified from 97 M8 and M9 progenies from self-pollination of SM2-244 using the GISH, These forty-three translocation lines were divide them into 7 types(Typel-Type7) based on the size, number and location of translocated fragment:Typel was homozygous fragmental reciprocal translocation with 44 chromosomes, type2 was homozygous terminal and small fragment translocation with 44 chromosomes, type3 was homozygous large fragmental translocation with 44 chromosomes, type4 was homozygous terminal translocation with 44 chromosomes, type5 was homozygous terminal translocation with 42 chromosomes, type6 was one large fragmental translocation with 42 chromosomes, and type7 was one terminal translocation with 42 chromosomes.2. Seven homozygous translocation types(Typel,Type2,Type3,Type4,Type5,Type6 and Type 7) were analyzed using FISH-GISH technology, and the results showed that the homozygous translocation chromosomes occurred between chromosome 5A of wheat and chromosome 6P of Agropyron cristatum L. Gaertn. The Tpye 1, type2, type3, type 4, type 5,Type6 and Type 7 could be described as T5AS5AL-6PL+T6PS 6PL-5AL (homo), T5AS 5AL-6PL+T6PL-5AL(homo), T6PS 6PL-5AL(homo), T5AS 5AL-6PL (homo) (44chromosome),T5AS 5AL-6PL(homo) (42chromosome), T6PS 6PL-5AL, T5AS 5AL-6PL,respectively. Besides, Type 2 was further detected with Probe CRW, and no signal of wheat chromosome centromere was discovered, which suggested that the centromere could be from. Agropyron cristatum L. Gaertn rather than wheat.3. The breakpoint of the Type5 translocation line was detected using the cytological diagnostic and molecular marker., and the resulted showed that 6PL0.32-1.00 fragment of Agropyron replaced 5AL12-0.35-1.0 fragment of wheat in chromosome 5A.The breakpoint of wheat chromosome was located within bin 5AL12-0.35-0.57 between the marker KsuM5 and KsuM56, and the breakpoint of 6P of Agropyron was closed to the point 6PL0.32.4. Agronomic traits were evaluated from different years as replication(2012 and 2013).The results showed that Typel,Type3 and Type6 significantly contained more tillers than that of control materials (P<0.01). The spikelet number per spike of Type2 was significantly more than that of negative control materials(P<0.05); the 1000-kernel weight of Type4 was significantly higher than that of negative control materials(P<0.05); The kernel number per spikelet of Type7 was significantly more than that of negative control materials(P<0.05). Analyzed the agronomic traits with translocated fragment and molecular marker,it suggested that there properly existed positive regulators of fertile tiller numbers and other yield traits on the 6PS and 6PL of A. cristatum chromosome, respectively.The study will not only provide the fundamental materials for improving wheat yield by transfering these elite yield genes by back-cross and molecular assisted selection, but also lay the foundation for the elucidation of the molecular mechanism of yield genes of A.cristatum.