Induction of haploid plants for speed-up breedıng in sunflower (Helianthus annuus L.) by pollen irradiation

Abstract

The creation of homozygous plants is essential for both genetic studies and the production of hybrid seeds, particularly in plants that were pollinated by an alien species. Dihaploid (DH) technology is an important application in obtaining homozygous lines used to plant speed breeding programs. The generation of haploid embryos by pollen irradiation and pollination of female flowers with irradiated pollen has been successfully applied. The influence of irradiated pollen on the induction of haploids in sunflower (Helianthus annuus L.) has been evaluated on 16 different sunflower lines from Turkey’s National Sunflower Breeding Program. In this study, pollen grains were irradiated with varying dosages of Gamma rays (500-1000 Gy) to generate parthenogenetic haploid embryos in oilseed sunflowers. At a period of 12–20 days following the process of pollination, embryos were plated into modified MS culture media under a 16/8 h photoperiod and a temperature of 25◦C. Parthenogenetic 18457 embryos at different developmental stages were rescued in vitro and 650 were germinated. The ploidy analysis of regenerants was made with chromosome count and flow cytometry. Except for 500 Gy, all dosages were effective for inducing embryos and haploid plants. Obtained results indicate that parthenogenetic haploid embryos can be produced in K3AD SN:8, IMI 069, and IMI 044 sunflower genotypes by selecting the appropriate Gamma ray dose and embryonic developmental stage. This study was focused to recover sunflower doubled haploids to accelerate the production of non-segregating lines for breeding.

Genomics-assisted speed breeding for crop improvement: present and future

“…As a result, different strategies are required to get over these restrictions and raise the production efficiency of sunflower DH. Promising results have been obtained by authors who managed to generate haploid embryos by pollen irradiation and pollination of female flowers with irradiated pollen (Aktaş et al, 2023). Another approach could be using immature embryo culture to shorten the generation time in breeding programs.…”