Identification Of Wheat-thinopyrum Intermedium Progeny 014-459 And Its F₁ Characterized By Male Sterility

Wheat male sterility is an economical-efficient way for producing hybrid seeds.Thus,extensive study on charater and molecular mechanism of male sterility would be valuable for utilization of heterosis.Common wheat line 014-459 is obtained from cross combination beween wheat-Th.intermedium partial amphiploid(Zhong 4)and common wheat Mian 980127.Two types of hybrid F₁ were gotten when wheat line 014-459 was crossed with different common wheats.One type is fertility,while another type is male sterility.In this study,(1)seed setting percentage of male sterile hybrid F₁ was evaluated under different sowing time.Pollen fertility,molecular cytogenetic characterization of 014-459 and both its fertility and sterility hybrids were studied;(2)Segregation population was constructed by pollinating014-459 with F₁ hybrids of Chuanmai 55 with Mian 08-9 and then phenotyped.SLAF-Seq-BSA(specific-locus amplified fragment sequencing and bulked segregant analysis)was used to genotype and mapping the chromosome regions causing male sterility;(3)Transcriptomes of anthers before flowering collected from 014-459,cultivar chuanmai 55 and hybrid F₁ derived from cross 014-459/chuanmai 55 were analysed to pick potentionly candidate gene.The main results were summarized as follows:1.Reciprocal crossing hybrid F₁s between 014-459 and cultivar chuanmai 55 were stably male sterility under different sowing time and the selfing rate arrived at less than0.5%in individual exceptional sowing time.However,the hybrid F₁ between 014-459 and Mian 08-9 was partily fertility with a seed set rate 33.66%.Chromosome pairing at meiosis metaphase I of 014-459 is almost nomal.In most meiosis metaphase I cells,chromosomes paired into 21 bivalents.Micronucleus at telophase was only observed in few cells.Similar chromosome behaviour during meiosis was also observed in both male sterility(014-459/Chuanmai 55)and male fertility F₁(014-459/Mian 08-9)hybrids.Thus,defectious meiosis chromosome behaviuos was not the reason causing male sterility in hybrids.2.Two alien chromosomes from Th.intermedium in strain 014-459 were identified by genomic in situ hybridization(GISH)use DNA of Th.intermedium as probe and DNA of Chinese Spring as block.Fluorescence in situ hybridization(FISH)analysis indicated a pair of 2A chromosome had deleted.The two alien chromosomes generally paired as bivalent at meiosis metaphase I,which indicated they are a pair of homologous chromosomes.The alien chromosome was confirmed derived from St genome by in situ hybridization using St genome DNA probe and St genome specific probe St₂-80.Polymerase chain reaction(PCR)-based landmark unique gene(PLUG)makers analysis suggested it was 6St.3.SLAF-Seq-BSA was used for detecting chromosomal interval associated with male sterility.The results showed that three intervals of chromosome 2D,1.67-17.58 Mb including 539 genes,62.59-63.73 Mb including 27 genes and 64.61-64.92 Mb including one gene,were associated with male sterility.4.The differences among transcriptomes of anthers collected from three materials014-459,cultivar Chuanmai 55 and hybrid F₁ derived from cross 014-459/Chuanmai 55were analysed in order to identify genes associated with male sterility.There were 2603common genes for differentially expressed genes between 014-459 and hybrid F₁(014-459/Chuanmai55)and those between Chuanmai 55 and hybrid F₁(014-459/Chuanmai55).One gene likely assoiated with target character was 2D01G027900with GO number 0009753 which was response to jasmonic acid.