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Polyembryony has been detected in 26 Allium species during a series of germination tests. Additionally to those species already known for their polyembryonic tendency, high rates (up to 32%) of twin seedlings have been found in A. splendens and some other species. Genotype effects were obvious between several accessions within the species A. tuberosum. In A. tuberosum, enzymatic embryo sac isolation has been used for demonstration of polyembryonic development in early stages. Genotype and ploidy dependence of the polyembryonic process and ploidy alterations in plants derived from polyembryony are discussed.

An attempt was made to establish a large number of virus- free garlic accessions in vitro, Virus- free in vitro plants of 87 accessions have been obtained via meristem culture. The virus- free status has been determined for the most frequent garlic viruses: OYDV, LYSV, GCLV. SLV and MbFV. In another 7 accessions one or more viruses were still present. The most persistent virus was GCLV. The occurrence of the other viruses was definitely lower. OYDV and LYSV have been eliminated to 85- 95 %. The detection of viruses in the plant was mainly performed by means of the ELISA technique using polyclonal and monoclonal antibodies. ISEM and decoration methods were used for the verification of the ELISA results. The results of ISEM confirmed the virus- free status of plants in all cases as determined by ELISA. In some cases viruses detected by ELISA could not be found by ISEM or the decoration method. On the other hand, in tests on MbFV with doubtful ELISA results, decoration tests gave a clear indication of virus infection. Small meristems from bulbils with one leaf primordium (0.3- 0.8 mm) were used for the establishment of meristem- tip cultures. The rate of plant regeneration varied between 1 % and 80 % of cultivated meristems and was dependent on the genotype. Meristem culture failed to result in plantlet regeneration in only 6 accessions. The influence of the culture medium was low compared with that of the genotype. The addition of ribavirin to the induction medium reduced the regeneration of plantlets, but virus elimination was significantly increased (from 19.6 to 59.3 %). Hot air treatment of bulbils at 36°C for 6 weeks did not reduce the survival of meristems. It was, however, favourable for virus elimination. Virus elimination was especially high, when thermotherapy and addition of ribavirin to the induction medium were combined.

A European project named EURALLIVEG (Vegetative Allium, Europe’s Core Collection, safe & sound) was performed under Council Regulation EC 870/2004 from 2007 until 2011. It was coordinated by IPK. The main focus of the project was the development of a European integrated Allium Core collection provided by national collections of Germany, Czech Republic, Poland, Italy, France, and Nordic countries. This collection was designed as a part of the European Genebank Integrated System (AEGIS) of the European Cooperative Program for Plant Genetic Resources (ECPGR). The project consists of five work packages: documentation, molecular screening, cryopreservation, virus elimination, and coordination. Main aim was identification of a core collection of the 200 most important garlic accessions. This collection was cryopreserved using vitrification, which is the most economic way for long term storage. A Cryobanks Network was organized by three project partners. This system ensures safe storage of material by adopting a safety duplicate strategy. The documentation of the collection used passport and characterization data, pictures and other information. In addition genetic fingerprinting with AFLP markers was conducted. In the project, the garlic accessions were introduced into meristem culture for virus elimination. Of the viruses present in garlic, Onion Yellow Dwarf (OYDV) and Leek Yellow Stripe (LYSV) Viruses are most harmful. Therefore, because of the impossibility to do all treatments and tests on all germplasm, it was decided to test the major part of the collection on OYDV and LYSV only. However, a specific part with higher priority (backbone subset) was examined for five viruses. Virus detection used ELISA testing.

Summary Fusicoccin (FC) induces changes of concentration potential and tissue resistance of corn coleoptiles within a few seconds after application. These changes are interpreted as a result of a rapid cell wall acidification caused by the plasmalemma proton pump stimulated by FC. Coleoptiles treated with indoleacetic acid (IAA) or light did not show any responses. A rough calculation of the amount of excreted protons is presented.