Isolation and application of P genome-specific DNA sequences of Agropyron Gaertn. in Triticeae

Abstract

Different types of P genome sequences and markers were developed, which could be used to analyze the evolution of P genome in Triticeae and identify precisely wheat- A. cristatum introgression lines. P genome of Agropyron Gaertn. plays an important role in Triticeae and could provide many desirable genes conferring high yield, disease resistance, and stress tolerance for wheat genetic improvement. Therefore, it is significant to develop specific sequences and functional markers of P genome. In this study, 126 sequences were isolated from the degenerate oligonucleotide primed-polymerase chain reaction (DOP-PCR) products of microdissected chromosome 6PS. Forty-eight sequences were identified as P genome-specific sequences by dot-blot hybridization and DNA sequences analysis. Among these sequences, 22 displayed the characteristics of retrotransposons, nine and one displayed the characteristics of DNA transposons and tandem repetitive sequence, respectively. Fourteen of 48 sequences were determined to distribute on different regions of P genome chromosomes by fluorescence in situ hybridization, and the distributing regions were as following: all over P genome chromosomes, centromeres, pericentromeric regions, distal regions, and terminal regions. We compared the P genome sequences with other genome sequences of Triticeae and found that the similar sequences of the P genome sequences were widespread in Triticeae, but differentiation occurred to various extents. Additionally, thirty-four molecular markers were developed from the P genome sequences, which could be used for analyzing the evolutionary relationship among 16 genomes of 18 species in Triticeae and identifying P genome chromatin in wheat-A. cristatum introgression lines. These results will not only facilitate the study of structure and evolution of P genome chromosomes, but also provide a rapid detecting tool for effective utilization of desirable genes of P genome in wheat improvement.

Chromosomal localization of genes conferring desirable agronomic traits from Agropyron cristatum chromosome 1P

“…cristatum repetitive sequence. Han et al [24] separated two A . cristatum repetitive sequence which could recognize A .…”

“…cristatum chromosomes could detect which A . cristatum chromosomes was included [24]. FISH procedure was described by Luan et al [15].…”

Construction of Agropyron Gaertn. genetic linkage maps using a wheat 660K SNP array reveals a homoeologous relationship with the wheat genome

“…Wheat– A. cristatum alien addition/substitution lines were obtained from several generations of backcrossing or selfing following the hybridization of the common wheat Fukuho with A. cristatum accession ‘Z559’ (2 n = 4 x = 28, PPPP) (Table ). Among these lines, II‐3‐1, II‐9‐1, II‐8‐1, II‐7‐1, II‐21‐2, II‐21‐6, 5113‐2, 5114‐3, 4844‐12, 4844‐8, 5038, 5043, II‐5‐1 and II‐26‐1 were identified previously (Han et al ., ; Pan et al ., ; Wu et al ., ). ‘Z1842’, ‘Z2098’ and their 119 progeny, Fukuho, ‘Z559’ and addition/substitution lines were planted in the glasshouse at the Chinese Academy of Agricultural Sciences, Beijing, China.…”

“…Subsequently, a set of additional wheat-A. cristatum lines and disomic substitution lines were produced and characterized (Han et al, 2017;Wu et al, 2006), some of which will be valuable for future wheat breeding as novel germplasms (Chen et al, 2012a;Wu et al, 2006). For example, the 6P disomic addition line 4844 shows high yield characteristics for the number of florets and kernels per spike compared with those of its wheat parent (Li et al, 1998;Wu et al, 2006), and resistance to powdery mildew and leaf rust was transferred from A. cristatum to common wheat .…”

Copy Number Variation of Transposable Elements in Thinopyrum intermedium and Its Diploid Relative Species

“…However, such approach is limited due to the complex organization of TEs and the assembly problem caused by huge TE redundancy and may not be accurate for genomes that have not been successfully assembled [77]. The dot-blot and Southern hybridization are time and labor consuming procedures [78,79] while fluorescent in situ hybridization provide only qualitative comparison between genomes [79,80]. Real-time quantitative polymerase chain reaction (qPCR) is a powerful tool that enables an accurate estimation of copy number in genomes [28,39,42,52,73,81].…”