Chen Peidu

Introduction of chromosome segment carrying the seed storage protein genes from chromosome 1V of Dasypyrum villosum showed positive effect on bread-making quality of common wheat

Key messageDevelopment of wheat-D. villosum1V#4 translocation lines; physically mapping theGlu-V1andGli-V1/Glu-V3loci; and assess the effects of the introducedGlu-V1andGli-V1/Glu-V3on wheat bread-making quality.AbstractGlu-V1 and Gli-V1/Glu-V3 loci, located in the chromosome 1V of Dasypyrum villosum, were proved to have positive effects on grain quality. However, there are very few reports about the transfer of the D. villosum-derived seed storage protein genes into wheat background by chromosome manipulation. In the present study, a total of six CS-1V#4 introgression lines with different alien-fragment sizes were developed through ionizing radiation of the mature female gametes of CS––D. villosum 1V#4 disomic addition line and confirmed by cytogenetic analysis. Genomic in situ hybridization (GISH), chromosome C-banding, twelve 1V#4-specific EST–STS markers and seed storage protein analysis enabled the cytological physical mapping of Glu-V1 and Gli-V1/Glu-V3 loci to the region of FL 0.50–1.00 of 1V#4S of D. villosum. The Glu-V1 allele of D. villosum was Glu-V1a and its coded protein was V71 subunit. Quality analysis indicated that Glu-V1a together with Gli-V1/Glu-V3 loci showed a positive effect on protein content, Zeleny sedimentation value and the rheological characteristics of wheat flour dough. In addition, the positive effect could be maintained when specific Glu-V1 and Gli-V1/Glu-V3 loci were transferred to the wheat genetic background as in the case of T1V#4S-6BS·6BL, T1V#4S·1BL and T1V#4S·1DS translocation lines. These results showed that the chromosome segment carrying the Glu-V1 and Gli-V1/Glu-V3 loci in 1V#4S of D. villosum had positive effect on bread-making quality, and the T1V#4S-6BS·6BL and T1V#4S·1BL translocation lines could be useful germplasms for bread wheat improvement. The developed 1V#4S-specific molecular markers could be used to rapidly identify and trace the alien chromatin of 1V#4S in wheat background.

Asymmetric somatic hybridization between haploid common wheat and UV-irradiated Haynaldia villosa

UV irradiated protoplasts from young embryo derived calli of Haynaldia villosa were fused with protoplasts originated from anther derived calli of Triticum aestivum cv. 24-2 by the PEG method. Regenerated calli from fusion cells were obtained but none of them differentiated into plants. The cell clones that formed early were examined for their hybrid nature, chromosome counting and isozyme analysis suggested that they were nuclear hybrid. Further unequivocal confirmation was accomplished using the technique of in situ hybridization (ISH) and RAPD analysis, which facilitated the identification of the hybrid nature in fusion products. The results revealed that UV might have played an important role in breaking donor chromosomes and ensuring the introduction of alien chromatin into the recipient via asymmetric hybridization. The failure of plant regeneration of the somatic hybrids was discussed and further investigations are being conducted.