Transfer of useful variability of high grain iron and zinc from Aegilops kotschyi into wheat through seed irradiation approach

Abstract

Purpose To transfer the 2S chromosomal fragment(s) of Aegilops kotschyi (2S^k) into the bread wheat genome which could lead to the biofortification of wheat with high grain iron and zinc content.

Materials and methods Wheat-Ae. kotschyi 2A/2S^k substitution lines with high grain iron and zinc content were used to transfer the gene/loci for high grain Fe and Zn content into wheat using seed irradiation approach.

Results Bread wheat plants derived from 40 krad-irradiated seeds showed the presence of univalents and multivalents during meiotic metaphase-I. Genomic in situ hybridization analysis of seed irradiation hybrid F₂ seedlings showed several terminal and interstitial signals indicated the introgression of Ae. kotschyi chromosome segments. This proves the efficacy of seed radiation hybrid approach in gene transfer experiments. All the radiation-treated hybrid plants with high grain Fe and Zn content were analyzed with wheat group 2 chromosome-specific polymorphic simple sequence repeat markers to identify the introgression of small alien chromosome fragment(s).

Conclusion Radiation-induced hybrids showed more than 65% increase in grain iron and 54% increase in Zn contents with better harvest index than the elite wheat cultivar WL711 indicating effective and compensating translocations of 2S^k fragments into wheat genome.

Keywords:

• Biofortification
• iron
• zinc
• wheat
• seed irradiation

Acknowledgements

The authors are thankful to the Institute of Nuclear Medicine and Allied Sciences (INMAS), New Delhi, for providing gamma chamber facility. The authors are highly grateful to the Department of Biotechnology, Govt. of India, for supporting the work through a network project “Biofortification of Wheat for enhanced Iron and Zinc content by conventional and molecular breeding- Phase-II”. Shailender Kumar Verma is highly grateful to Council of Scientific and Industrial Research for providing fellowship.

Disclosure statement

The authors report no conflict of interest. The authors alone are responsible for the content and writing of the paper.