Results of crosses between Hordeum bulbosum (2x) and H. vulgare (2x) are presented. Nine H. vulgare genotypes of different crossability with H. bulbosum were treated both as female and male parents. Immature embryos were cultured in vitro according to ADAMSKI and SURMA (1994). Seeds set, embryo development and obtained haploid plants were recorded. It was shown that seed setting and haploid plant efficiency (haploids/100 florets) were about ten times lower in H. bulbosum x H. vulgare than in H. vulgare × H. bulbosum The cvs. Vada, Apex and the doubled haploid line KA7/3 (related to Apex) which showed a low crossability in H. vulgare × H. bulbosum, gave a relatively high seed setting in reciprocal crosses. The obtained results indicate that partial incompatibility of some H. vulgare genotypes with H. bulbosum could be cytoplasmatically influenced.
The androgenetic response of several selected male sterilitymaintainer genotypes of triticale was investigated. Androgenesis induction was obtained in all cultivars, but a large genotypic variation in green plant regeneration was observed. The number of regenerated triticale plants varied from 0.1 to 4.7 green plants per spike, depending on genotype. Spontaneous doubling of chromosomes varied from 14 to 60 % for particular genotypes and, on average, reached the value of 34 % for all genotypes. Fertile DH lines obtained in this study will find practical application in the development of triticale male sterile lines that are desirable in hybrid breeding.
The utility of haploids and DH lines for breeding programmes and basic research is discussed here. High effectiveness of haploid induction from random responding gametes and from valuable donor plants is not sufficient to ensure success in breeding. DH lines often appeared inferior to conventionally obtained inbred lines. One of the causes may be a very high level of homozygosity, in this paper referred to as excessive homozygosity. Besides, colchicine treatment as well as gametoclonal and somaclonal variation could have a negative effect on the agronomic performance of DH plants. Lack of natural selection in the first stages of haploid development is another important factor, negatively influencing haploid utility. On the other hand, there is a wide range of possibilities of using haploids as model plants for basic research. Among different applications, including mapping, genetic analysis, mutations, transformation, somatic hybridisation, biochemical and physiological studies, artificial seed production and germplasm storage, the first seems to be explored most effectively and give promising results.
This paper briefly cites the various procedures for the production of doubled haploids in barley and wheat. Various associated terms are defined and the factor involved in haploid production are outlined. Isolated microspore cultures offer some advantages over anther culture. Our current procedures for isolated microspore culture of barley and wheat are presented and compared.