Microspore growth and anther staging in barley anther culture

Isolated Microspore Culture in Barley

Isolated microspore culture (IMC) is the most efficient way to produce large numbers of doubled-haploid (DH) barley plants in a short time. Yet, while IMC is more cost-efficient and less labor-intensive than anther culture, it is technically more complex and requires more experienced personnel if it is to yield its full potential. In part, this is because of multiple and important interactions that exist between factors at its many different phases, including genotype effects as well. When every phase is fine-tuned, the protocol that is presented below yields a useful number of DHs with almost all genotypes and can allow the production of up to 300 DH plants from a single F1 plant in just a few months.

Androgenic response of barley accessions and F1s with Fusarium head blight resistance

Most Fusarium head blight (FHB) resistant barley (Hordeum vulgare L.) accessions perform relatively poorly from an agronomic point of view. Due to the polygenic inheritance of FHB resistance, introgression of this complex trait into well-adapted elite germplasm will likely require multiple cycles of hybridization and selection to combine resistance and agronomic performance. The use of anther culture to produce doubled haploids would seem well justified to reduce the time required to achieve this goal. Unfortunately, little is known concerning the androgenic response of the small number of genotypes with known partial FHB resistance. To make the best use of such FHB resistance donors in a barley improvement program, we first characterized the FHB resistance of eight reported FHB resistance sources (Chevron, Gobernadora, Seijo II, Shyri, Svanhals, Zhedar I, F104-250-9 and C97-21-38-3) in our own FHB nursery in Quebec City (QC, Canada). In parallel, we assessed the androgenic response of these same eight lines with that of three cultivars (ACCA, Léger and Cadette) of known androgenic response. Finally, the androgenic response of F(1) hybrids involving some of these genotypes used as parents was measured and compared to that of the parental genotypes. Very large and significant differences were observed in the number of green plants produced by the different accessions and F(1)s. Although anther culture seemed very promising for some accessions, for others, the androgenic response was so low that a conventional approach would seem more appropriate.

Arabinogalactans and arabinogalactan-proteins induce embryogenesis in wheat (Triticum aestivum L.) microspore culture

The objective of this study was to improve induction of embryogenesis in wheat microspore culture in order to obtain a high number of regenerable embryos. The arabinogalactan (AG) Larcoll and the arabinogalactan-protein (AGP) from gum arabic were tested on two spring genotypes to see if they could increase microspore viability and induce embryogenesis in the microspore culture. Adding Larcoll significantly decreased microspore mortality in both genotypes regardless of the presence or absence of ovaries in the culture. Similarly, gum arabic had a strong effect on the number of embryos produced and regenerated green plants. In fact, by using only gum arabic we were able to obtain green plants from wheat microspore cultures without the presence of ovaries. In addition to preventing a high mortality rate of the cells, our results show that the induction of embryogenesis in wheat microspore cultures is strongly affected by the use of both AG or AGP.