# Usefulness of alien sterilizing cytoplasms for the hybrid breeding of triticale (xTriticosecale Wittmack): preliminary results

## TL;DR

This study explores new sources of male sterility in triticale to improve hybrid breeding, finding some promising but imperfect options.

## Contribution

The paper identifies alternative cytoplasmic male sterility sources for triticale hybrid breeding beyond Triticum timopheevi.

## Key findings

- Pampa and Aegilops sharonensis cytoplasms showed moderate success in restoring male fertility in triticale hybrids.
- Triticum timopheevi and Ae. ventricosa cytoplasms maintained male sterility in hybrids.
- None of the cytoplasms were definitively ruled out for future breeding programs despite limitations.

## Abstract

To be useful for cereal breeding, cytoplasmic male sterility (CMS) should express the complete sterility of maternal lines and the full restoration of the male fertility of F1 hybrids. The most reliable source of sterilizing cytoplasm for triticale is Triticum timopheevi; however, due to the low frequency of efficient non-restorer genotypes for this cytoplasm, new sources of CMS are needed. In this study, aside from T. timopheevi (T) cytoplasm, three alternative CMS sources were tested: Pampa (P) from Secale cereale L., Aegilops sharonensis (A), and Ae. ventricosa (V). The suitability of these cytoplasms for breeding was assessed based on the male fertility/sterility of F1 hybrids obtained through the manual pollination of CMS maternal lines with 36 triticale cultivars and breeding strains. About half of the hybrids with each type of cytoplasm were fully fertile and produced more than 30 grains per bagged spike. The highest percentage was found in hybrids with P cytoplasm (58.33%) and the lowest in hybrids with A cytoplasm (44.44%). Male sterility was observed in hybrids with P cytoplasm (16.67%) and A cytoplasm (16.67%) but not in hybrids with T or V cytoplasm. In terms of practical aspects, male sterility systems with P or A cytoplasm exhibit similarity in their ability to restore male fertility that differ from the T and V cytoplasms. Although all studied cytoplasms exhibited some disadvantages for breeding purposes, none should be definitively classified as unacceptable for future breeding programs regarding the development of triticale hybrid cultivars.