Phenotypic effects of the U-genome variation in nascent synthetic hexaploids derived from interspecific crosses between durum wheat and its diploid relative Aegilops umbellulata

Abstract

Aegilops umbellulata is a wild diploid wheat species with the UU genome that is an important genetic resource for wheat breeding. To exploit new synthetic allohexaploid lines available as bridges for wheat breeding, a total of 26 synthetic hexaploid lines were generated through crossing between the durum wheat cultivar Langdon and 26 accessions of Ae. umbellulata. In nascent synthetic hexaploids with the AABBUU genome, the presence of the set of seven U-genome chromosomes was confirmed with U-genome chromosome-specific markers developed based on RNA-seq-derived data from Ae. umbellulata. The AABBUU synthetic hexaploids showed large variations in flowering-and morphology-related traits, and these large variations transmitted well from the parental Ae. umbellulata accessions. However, the variation ranges in most traits examined were reduced under the AABBUU hexaploid background compared with under the diploid parents. The AABBUU and AABBDD synthetic hexaploids were clearly discriminated by several morphological traits, and an increase of plant height and in the number of spikes and a decrease of spike length were commonly observed in the AABBUU synthetics. Thus, interspecific differences in several morphological traits between Ae. umbellulata and A. tauschii largely affected the basic plant architecture of the synthetic hexaploids. In conclusion, the AABBUU synthetic hexaploid lines produced in the present study are useful resources for the introgression of desirable genes from Ae. umbellulata to common wheat.

Phenotypic effects of Am genomes in nascent synthetic hexaploids derived from interspecific crosses between durum and wild einkorn wheat

“…tauschii (DD) and Ae. umbellulata (UU) [31,37]. The AABBA m A m synthetic lines were derived from the same mother parent, Ldn.…”

“…Phenotypic comparisons between AABBDD synthetic wheat and AABBUU synthetic hexaploids indicated that differences in phenotypic traits between these nascent synthetic hexaploids re ect the genomes of their pollen parents [31]. To test whether this observation could extend to the other nascent synthetic hexaploids, we compared phenotypic traits of the AABBDD synthetic wheat with those of the AABBA m A m and AABBAA synthetic hexaploids (Fig.…”

“…Four grain-related traits, grain hardness, weight, diameter, and moisture were evaluated using SKCS 4100 (Perten, Stockholm, Sweden). The SKCS hardness index was obtained from crushing a sample of at least 50 kernels from Ldn and each synthetic line, similar to our previous report [30,31].…”

“…Synthetic hexaploid lines were recently developed through crosses of Ldn and various accessions of Aegilops umbellulata Zhuk. [30,31]. The AABBUU synthetic lines are expected to enlarge the diversity in grain hardness, heading/ owering date, and spike/spikelet morphology in common wheat.…”

Image-Based, Organ-Level Plant Phenotyping for Wheat Improvement

“…Both packages have been widely employed in wheat research. SmartGrain has been leveraged to explore the genetics underlying yield components [98][99][100][101][102], to aid breeding and introgression [103][104][105], and to analyze drought response [106]. GrainScan has been used in the exploration of yield genetics [107,108], the evaluation of ancestral germplasm [109], and in the unraveling of wheat domestication [110].…”