Induction of Triticale (×Triticosecale Wittmack) In Vitro Androgenesis in Anther Cultures of F1 Hybrid Combinations, Varieties and Homogeneity Testing of Offspring Generation

In cereal breeding, in vitro androgenesis methods are frequently applied to achieve doubled haploid (DH) plants. The aim of this study was to determine the effects of genotype (three registered varieties and eight F1 crossing combinations) and induction medium (W14mf and P4mf) on anther cultures (ACs) of triticale (×Triticosecale Wittmack). Androgenesis was induced in the treatment of each tested genotype, and the genotype significantly influenced the efficiency of AC, including in embryo-like structures (ELSs), albinos, green plantlets, and transplanted plantlets. The utilized medium also had a significant effect on the number of ELSs, albinos, and transplanted plantlets. Both media were suitable for AC in triticale DH plant production. The efficiency of AC was higher when using the P4mf medium (103.7 ELS/100 anthers, 19.7 green plantlets/100 anthers) than when using the W14mf medium (90.0 ELS/100 anthers, 17.0 green plantlets/100 anthers). However, the green plantlet regeneration efficiency of microspore-derived structures was 18.0% when using the W14mf medium, while this value was 15.9% in the case of ELSs induced with the P4mf medium. After nursery seed evaluation and propagation (DH1), the genetic homogeneity of the offspring generation (DH2) was tested using a molecular genetic method. Most of the tested DH lines showed homogeneity and were progressed into a breeding program after agronomic selection. Some DH lines showed inhomogeneity, which could be explained by the outcross inclination of triticale. We would like to call breeders' attention to the outcross character of triticale and emphasize the vigilant propagation and maintenance of the triticale DH lines in breeding programs. Due to the outcross nature of triticale, even in self-pollinated genotypes, breeders should focus on careful maintenance, along with isolation in the case of line propagations, in triticale breeding programs.

Crop breeding for a changing climate in the Pannonian region: towards integration of modern phenotyping tools

The Pannonian Plain, as the most productive region of Southeast Europe, has a long tradition of agronomic production as well as agronomic research and plant breeding. Many research institutions from the agri-food sector of this region have a significant impact on agriculture. Their well-developed and fruitful breeding programmes resulted in productive crop varieties highly adapted to the specific regional environmental conditions. Rapid climatic changes that occurred during the last decades led to even more investigations of complex interactions between plants and their environments and the creation of climate-smart and resilient crops. Plant phenotyping is an essential part of botanical, biological, agronomic, physiological, biochemical, genetic, and other omics approaches. Phenotyping tools and applied methods differ among these disciplines, but all of them are used to evaluate and measure complex traits related to growth, yield, quality, and adaptation to different environmental stresses (biotic and abiotic). During almost a century-long period of plant breeding in the Pannonian region, plant phenotyping methods have changed, from simple measurements in the field to modern plant phenotyping and high-throughput non-invasive and digital technologies. In this review, we present a short historical background and the most recent developments in the field of plant phenotyping, as well as the results accomplished so far in Croatia, Hungary, and Serbia. Current status and perspectives for further simultaneous regional development and modernization of plant phenotyping are also discussed.

In Vitro Anther Culture for Doubled Haploid Plant Production in Spelt Wheat

Doubled haploid (DH) plant production belongs to modern biotechnology methods of plant breeding. The main advantage of DH plant production methods is the development of genetically homozygous lines in one generation, whilst in conventional breeding programmes, the development of homozygous lines requires more generations. The present chapter describes an efficient protocol for DH plant production in spelt wheat genotypes using in vitro anther culture.

Unpollinated Ovaries Used to Produce Doubled Haploid Lines in Durum Wheat

The use of doubled haploid lines improves the efficiency of cultivar development and homozygous genotypes can be obtained in one generation, as opposed to conventional line production, which requires several cycles of self-pollination. However, in durum wheat (Triticum turgidum subsp. durum Desf.), the low efficiency of green plant regeneration and the very high frequency of albino plants hinder the application of this technique.We observed the success of using gynogenesis for durum wheat and the significant influence of growing conditions on ovary and callus development, and on plant regeneration. Our results suggested that the cold pretreatment for 2 weeks is efficient for durum wheat. Furthermore, the addition of 2,4-D, vitamins and glutamine, and the use of maltose as sugar source in media improved the ovary regeneration. We describe in this work an efficient method to regenerate green plants from in vitro durum wheat gynogenesis .

Homozygous Transgenic Barley (Hordeum vulgare L.) Plants by Anther Culture

Production of homozygous lines derived from transgenic plants is one of the important steps for phenotyping and genotyping transgenic progeny. The selection of homozygous plants is a tedious process that can be significantly shortened by androgenesis, cultivation of anthers, or isolated microspores. Doubled haploid (DH) production achieves complete homozygosity in one generation. We obtained transgenic homozygous DH lines from six different transgenic events by using anther culture. Anthers were isolated from T0 transgenic primary regenerants and cultivated in vitro. The ploidy level was determined in green regenerants. At least half of the 2n green plants were transgenic, and their progeny were shown to carry the transgene. The process of dihaploidization did not affect the expression of the transgene. Embryo cultures were used to reduce the time to seed of the next generation. The application of these methods enables rapid evaluation of transgenic lines for gene function studies and trait evaluation.

Utilization of in Vitro Anther Culture in Spelt Wheat Breeding

The efficiency of in vitro anther culture was screened in a full diallel population of four spelt wheat genotypes and ten F1 hybrids. Genotype dependency was observed based on the data of embryo-like structures (ELS), green-, albino plantlets. In the diallel population and ten F1 hybrids, the green plantlets production ranged from 13.75 to 85.00 and from 6.30 to 51.00, respectively. The anther culture-derived plants of F1 hybrids were grown up in the nursery. At the harvest, 436 spontaneous doubled haploid (DH) plants were identified among the 1535 anther culture-derived transplanted and grown up individual plants. The mean of spontaneous rediploidization was 28.4% which ranged from 9.76% to 54.24%. In two consecutive years, the agronomic values of 'Tonkoly.pop1' advanced line were compared with seven DH lines of 'Tonkoly.pop1' in the nursery. The DH lines achieved competitive values in comparison with 'Tonkoly.pop1' advanced line based on the 11 measured parameters (heading date, plant height, yield, hardness, width and length of seed, TKW, hulling yield, flour yield, protein and wet gluten content). These observations presage the efficient utilization of anther culture in spelt wheat breeding.