The effects of chromosome 6P on fertile tiller number of wheat as revealed in wheat-Agropyron cristatum chromosome 5A/6P translocation lines

Abstract

This study explored the genetic constitutions of several wheat- A. cristatum translocation lines and determined the effects of A. cristatum 6P chromosome segments on fertile tiller number in wheat. Progress in wheat breeding is hampered by a relatively narrow range of genetic variation. To overcome this hurdle, wild relatives of common wheat with superior agronomic traits are often used as donors of desirable genes in wheat-breeding programs. One of the successfully utilized wheat wild relatives is Agropyron cristatum (L.) Gaertn (2n = 4x = 28; genomes PPPP). We previously reported that WAT31-13 was a wheat-A. cristatum 5A-6P reciprocal translocation line with higher fertile tiller number and grain number per spike compared to common wheat. However, WAT31-13 was genetically unstable. In this study, we analyzed the 43 genetically stable progenies from WAT31-13 using genomic in situ hybridization, dual-color fluorescence in situ hybridization, and molecular markers. We classified them into three translocation types (TrS, TrL and TrA) and seven subtypes, and also pinpointed the translocation breakpoint. The genotypic data, combined with the phenotypes of each translocation type, enabled us to physically map agronomic traits to specific A. cristatum 6P chromosome arms or segments. Our results indicated that A. cristatum chromosome 6P played an important role in regulating fertile tiller number, and that positive and negative regulators of fertile tiller number existed on the A. cristatum chromosome arm 6PS and 6PL, respectively. By exploring the relationship between fertile tiller number and A. cristatum chromosome segment, this study presented a number of feasible approaches for creation, analysis, and utilization of wheat-alien chromosome translocation lines in genetic improvement of wheat.

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

“…cristatum STS markers were used to determine wheat- A . cristatum 6P addition line and locate genes on different chromosome segments [8, 15–17, 42]. In this study, 56 EST-STS markers specific to chromosome 1P were screened from A .…”

“…and common wheat, but also obtained a series of stable wheat- A . cristatum addition lines and translocation lines, such as 2P disomic addition line and translocation line [5, 14], 6P disomic addition line, substitution line and translocation line [4, 7, 8, 15–17], and 7P disomic addition line and translocation line [18]. However, 1P, 3P, 4P and 5P addition lines have not been reported.…”

Chromosomal Localization of Genes Conferring Desirable Agronomic Traits from Wheat-Agropyron cristatum Disomic Addition Line 5113

“…Genomic in situ hybridization (GISH) was used to analyze the chromosomal composition of 5113 and the progenies of the genetic populations as previously described [33]. Genomic DNA was isolated using the modified CTAB method [36].…”

Molecular cytogenetic characterization of a new wheat-rye 1BL•1RS translocation line expressing superior stripe rust resistance and enhanced grain yield

“…To date, many alien genes/ QTLs conferring superior traits have been transferred into cultivated wheat by developing wheat-alien species translocation lines (Jiang et al 1994;Friebe et al 1996;Singh et al 1998;Lukaszewski 2000;Ren et al 2009;Luan et al 2010;Gill et al 2011;Kang et al 2011;Qi et al 2011;Larson et al 2012;Chen et al 2013;Niu et al 2014;Cainong et al 2015;Zhang et al 2015a, b). Some translocation lines, including 1RS of rye (Secale cereale), 6VS of Dasypyrum villosum, 2S of Aegilops speltoides, 7Ag of Thinopyrum ponticum, and 6P of Agropyron cristatum, are the most successful examples of the introgression of elite genes from the wild relatives in wheat improvement (Lukaszewski1990; Singh et al 1998;Klindworth et al 2012;Chen et al 2013;Niu et al 2014;Ye et al 2015;Zhang et al 2015a).…”