Genetic transformation is widely used to improve target traits and to study gene function in wheat. However, transformation efficiency depends on the physiological status of the recipient genotype and that is affected by several factors including powdery mildew (PM) infection. The widely used recipient variety Fielder is very susceptible to PM. Therefore, it would be beneficial to develop PM resistant derivatives with high regeneration ability for use in genetic transformation. In the present study PM resistant lines CB037 and Pm97033 carrying genes Pm21 and PmV, respectively, were backcrossed to Fielder with selection for PM resistance. Five lines, NT89, NT90, NT154, and WT48 with Pm21 and line FL347 with PmV were developed, identified by molecular markers and genomic in situ hybridization (GISH) or fluorescent in situ hybridization (FISH), and further subjected to detailed assessment of agronomic traits and regeneration ability following genetic transformation capacity. Lines FL347, WT48, NT89 and NT154 assessed as being equal to, or superior, to Fielder in regeneration and transformation ability are recommended as suitable materials for the replacement of Fielder for wheat gene transfer and genome editing study.

Wheat bread-making quality can be improved by use of high-molecular-weight glutenin subunits (HMW-GSs) from wild relatives. Aegilops longissima is a close relative of wheat that contains a number of HMW-GS-encoding genes including 1S^lx2.3*. In this study, transgenic wheat lines overexpressing 1S^lx2.3* were obtained by Agrobacterium-mediated transformation and used to investigate the genetic contribution of 1S^lx2.3* to wheat flour-processing quality. The 1S^lx2.3* transgene was stably inherited and expressed over generations. Expression of 1S^lx2.3* increased the relative expression of 1Dx2 and 1Dy12 and reduced that of 1By18 during grain development. In general, integration of 1S^lx2.3* stimulated the accumulation of endogenous HMW-GSs and low-molecular-weight glutenin subunits in wheat kernels, greatly increasing the glutenin: gliadin ratio and resulting in faster formation of protein bodies in the endosperm during grain development. A wheat material with improved flour-making quality was developed in which 1S^lx2.3* improved wheat bread-making quality.

Thinopyrum intermedium and barley are two close relatives of wheat and carry many genes that are potentially valuable for the improvement of various wheat traits. In this study we created wheat double substitution lines by hybridizing different wheat–Th. intermedium and wheat–barley disomic alien substitution lines, with the aim of using genes in Th. intermedium and barley for wheat breeding and investigating the genetic behavior of alien chromosomes and their wheat homoeologs. As expected, we obtained two types of wheat double substitution lines, 2D2Ai#2(2B)2H(2A) and 2A2Ai#2(2B)2H(2D), in which different group 2 wheat chromosomes were replaced by barley chromosome 2H and Th. intermedium chromosome 2Ai#2. The new materials were characterized using molecular markers, genomic in situ hybridization (GISH), and fluorescent in situ hybridization (FISH). GISH and FISH experiments revealed that the double substitution lines harbor 42 chromosomes including 38 wheat chromosomes, a pair of barley chromosomes, and a pair of Th. intermedium chromosomes. Analysis using specific DNA markers showed that two pairs of wheat homoeologous group 2 chromosomes in the new lines were substituted by a pair of 2H and a pair of 2Ai#2 chromosomes. Chromosome 2H showed a higher transmission rate than 2Ai#2, and both chromosomes were preferentially transmitted between generations via female gametes. Evaluation of botanic and agronomic traits demonstrated that, compared with their parents, the new lines showed similar growth habits and plant type but differences in plant height, flowering date, and self-fertility. Cytological observations using different probes suggested that the double substitution lines showed nearly normal genetic behavior before and during meiosis. The novel substitution lines can potentially be used in wheat meiosis research and breeding programs.

Genome editing is one of the most promising biotechnologies to improve crop performance. Common wheat is a staple food for mankind. In the past few decades both basic and applied research on common wheat has lagged behind other crop species due to its complex, polyploid genome and difficulties in genetic transformation. Recent breakthroughs in wheat transformation permit a revolution in wheat biotechnology. In this review, we summarize recent progress in wheat genetic transformation and its potential for wheat improvement. We then review recent progress in plant genome editing, which is now readily available in wheat. We also discuss measures to further increase transformation efficiency and potential applications of genome editing in wheat. We propose that, together with a high quality reference genome, the time for efficient genetic engineering and functionality studies in common wheat has arrived.