Genetic Analysis Of Breeding Related Traits Of Fan6 And Development And Validation Of Specific Molecular Markers For Chromosome 7EL From Thinopyrum Elongatum

Wheat ?Triticum aestivum? is one of the most important crop in the world. In China, founder parents played great roles in wheat breeding because many of their excellent characters, and good combining ability with other strains during hybridization, producing a series of offspring which were planted widely. Founder parent Fan6 ?Yibo1828/India824/3/Sichuanwuyimai//Chengduguangtou/Zhonnnong483/4/Zhongnong-28B/Yibo1828//India824//Afu? was born through convergent hybriding by professor Yen-C., with good abilities such as strip rust resistance. Fan6 was widly planted in Sichuan in 1970s, with annual planting area of more than 3.5hm2. Most characteristics of Fan6 delivered well in its derivatives and many derivatives were planted in Sichuan wheat region widely. Therefore, it is important to analyze breeding traits of Fan6 geneticly and identify good loci related with different traits for wheat breeding in Sichuan province. Diploid Thinopyrum elongatum?also called Lophopyrum elongatum, Agropyron elongatum and Elytrigia elongatum? ?2n=14, EE genome? has many excellent features, and the successful bridization of its E genome with wheat promoted genes from Thinopyrum elongatum transferring to wheat, leading to wheat improvement in genetic level. Cytologh and molecular studies showed that there were FHB resistant gene in the long arm of Thinopyrum elongatum chromosome 7E, therefore, exploring and validating specific markers for 7EL will provide effect basis for future study about resistant loci in chromosome 7EL. In this study, we tested agronomic, yield and qualitic traits of Fan6 and its derivatives accurately to identify phenotypes of Fan6. Meanwhile, SNP markers were used to analyze genetic effects of breeding related traits in Fan6. On the other hand, we constructed cDNA library of Th. Elongatum 7EL chromosome after infecting by Fusarium, and developed and validated 7EL specific molecular marker through bioinformatics methods. The results obtained in this study are shown as follows:1. Based on two-year-one-location identification of agronomic traits and yield components of Fan6 and its derivatives, we wanted to make clear of characteristics and trend of these traits. We found that most traits delivering stably from Fan6 to its derivatives based on average value comparation of plant height, spike length, spikelets number per spike, kernel number per spikelet, kernel weight per spike, thousand kernel weight and effect tilling number, proving that good combining ability of Fan6 with many traits. In addition, we found through correlation analysis of agronomic and yield traits of Fan6 and its derivatives that many traits such as yield per plant and tilling number correlated significantly, which may lead to well development of Fan6 in Sichuan wheat area.2. Based on two-year-one-location identification of qualitative traits of Fan6 and its derivatives, we want to make clear of characteristics of these traits. Because,of natural conditions, the average level of protein content of Sichuan wheat was low. Most of flour from Fan6 and its derivates belonged to low-gluten and medium-gluten flour, which was inextricably affected by the content and quality of wheat grain protein. Gluten content and sedimentation value were affected by environment significantly, and garinogragh parameters were impacted by environment slightly.3. Genetic analysis of agronomic traits and yield components was processed using SNP markers. Stucture analysis showed that there were 5 subpopulations for Fan6 and its derivatives, LD distance in total group was 1.3cM. Based on Fan6 specific markers and MLM,371 marker-trait-associations ?MTAs? were found with 16 traits ?p<0.05?,31 of which repeated in two environments or more, locating on chromosome 1D,2B,3A,3B,3D, 4A,4B,5A,5B,6A,6B,7A and 7D, and associating with 11 traits:plant height, uppermost internode length, spike lenth, flag leaf width, tilling number, effect tilling number, thousand kernel weight, kernel width, kernel length, spikelets number per spike and sterile spikelets number. Besides,3 MTAs wsnp_Ra_c2842₅399988, wsnp_Ku_c2562₄879681 and wsnp_JD_rep_c48937₃3188230 were associated with two traits or more. There was a region, wsnp_RFL_Contig4307₅006558 -wsnp_Ex_c1279 2451582, on chromosome 5A relating with plant height, flag leaf with, sterile spikelets number and spikelets number per spike, indicating that this region may be important relationg with agronomic traits in Fan6 and its derivatives.4. Genetic analysis of qualitative traits was processed using SNP markers. Based on GLM and MLM,4614 SNP markers were used for association with 6 qulity traits. Result showed that 134 MTAs were found with all traits ?p< 0.01?, on chromosome 1A, 1B,2A, 2B,2D.3A,3B,4A,4B,4D,5A,5B,5D,6A,6B,7A,7B and 7D, beside,10 MTAs on chromosome 2A,2B,4A,5A,6A,7A and 7D were associated with more than two traits. Besides, a MTA on chromosome 4A, wsnp_Ku_c9746₁6265584, associationg with dry gluten content ?p< 0.01? wet gluten content ?p<0.05?, was Fan6 specific.5. cDNA library was constructed based on RNA-Seq data of Chinese Spring ?CS? and Chinese Spring-Th. Elongatum 7EL addition line ?CS-7EL?, from which 135 candidate 7EL specific expressed genes were screened by comparing with public date. Primers were designed for these 135 genes and PCR amplification were then prosessed, and 47 7EL specific markers. Specificity of these markers were tested through Chinese Spring-Th. elongatum disomic addition lines ?chromosomes 1E to 7E? and stability of markers were tested though Chinese Spring-Th. elongatum disomic substitution lines ?with 7E replacing 7A,7B, or 7D?. Meanwhile, effect of markers were tested using 47 meterials of BC1F2 ?CS-7E?7D?×CSphIb?.