The author dealt with plum species representing different eco-geographic areas by their genetic adaptation and their hybrids, as European (P. domestica, P. italica, P. cerasifera), Asian (P. salicina, P. simonii, P. ussuriensis), American (P. ame...ricana, P. besseyi, P. munsoniana, P. tomentosa). The rootstocks of the trees examined were seedlings of C. 679 myrobalan with the exception of Laroda and Santa Rosa II, which were grown on three different stocks: seedlings of C. 174 myrobalan, C. 449 bitter almond and C. 471 sweet almond. The size of peduncle, length of pistil, stamen number per flower, relative stamen number (SN/PL) have been suitable for description and distinction of varieties. Similarly shape of leaves, length of petiole, length and width of blade helped the identification.
The ratio of the dimensions of leaves, length of petiole and of leaf blade, also contributed to the distinction of European, Asian and American plum species, notwithstanding their relations with ecological conditions as well as historical, technical properties, pomological features, etc. Computed indicators (relative stamen number and shape-index of leaves) also have been useful data.
Significant correlations have been found between colour of nectaries and mean values of variety-groups. The potential values of non-European varieties for purposes of commercial production could be forecasted from the point of view of quality, ecological, pomological as well as market value. It is important, however, to know the effect of the rootstock and growing site as well as their interaction, on the one hand, whereas the resistance or tolerance of the varieties as limiting factors, at least to the sharka (Plum pox) virus, Xanthomonas pruni, on the other hand (cf. Surányi & Erdős, 2004a and 2004b).
The program of the Research Institute of Cegléd, comprises the acclimation and selection of 7 Prunus-species and 39 cultivars grafted on Myrobalan C. 679 (P. cerasifera) seedling stocks. In addition two varieties have been investigated on three different rootstocks each: Myrobalan C. 174 (P. cerasifera),... Bitter almond C. 449 (P. arnygdalus var. amara) and Sweet almond C. 471 (P. amygdalus var. dulcis). Fruits of commercial quality are produced maroly on some cultivars of P. salicina-, P. italica- and P. cerasifera character. Authors explain the three possible causes of low yields experienced in non-European plums:
1/ unfavorable environmental conditions
2/ lack of irrigation and
3/ superficial information concerning the variety, rootstock and adequate traditions as well as growing practices.
A rather tight correlation has been stated between blooming dates and the main ripening period. However, the early blooming time alone cannot be considered as the cause of low productivity. The decay of plum trees is attributed to special ecological requirements and phytosanitary problems of the foreign plum cultivars. The analysis of regression revealed stochastic relations involving several other characters too, which facilitate the planning of cross-combinations in the breeding program.
In vitro culture conditions were experimented for the relatively sensitive, but very esthaetic "Caribe" variety of carnation with uniformly dark violet flowers. Regeneration of new plants from shoot apex meristems can be significantly improved by the combined addition of very low amounts of indolebutiric acid, benzyladenine and gibbere...lic acid, dissolved in the Murashige-Skoog nutrient medium. Callus formation as a prerequisite for the induction of somaclonal variability can be achieved successfully with certain molar ratios between 2,4-dichlorophenoxyacetic acid and benzyladenine. Acclimation of the obtained mericlones to the ex vitro conditions was also evaluated.
The cooperation of Hungarian professionals with Chinese, Thai, South-Korean, Taiwanese and Brazilian colleagues should deserve much more attention than actually done. We refer to the transfer and adaptation of production technologies as well as biotechnological developments in vegetables, fruits, ornamentals and medicinal plants from the Temper...ate Zone to the tropical and subtropical regions. According to our information Hungarian colleagues involved in extension work are highly esteemed on the same level as Japanese, Chilean, Italian and French colleagues. We could state that immigration of investors, local enterpreneurs as well as those coming from expansive regions of Europe, North America and oversses, representaives of supermakets keeps to be accelerated by the increasing confidence triggered also by the successful management of profitable plantations, vineyards and fruits initiated first about 15 years ago.
For Hungary, the presence and achievements of Hungarian horticultural expertise in tropical and subtropical zones yielded unequivocal advantages. Therefore, the next actual step of development would mean the organisation of a network of the "Units of Horticultural Mission" in the tropic and subtropic countries. We are convinced that those Units will stimulate the traffic of technologies as centers of transfer within and between the regions and contribute to the increasing influence of professionals on the production and trade of horticultural commodities. The introduction and testing of new varieties of vegetables, fruits, medicinal plants (as well as ornamentals), the development of the growing technologies, adaptation and acclimation of Temperate Zone germ plasm representing the general trends of advanced production will be the most important tasks of the Mission with a sufficient oversight upon the whole world. It is taken as a fact that Hungarian horticulture and breeding is competitive on the world market. We are ready to contribute to the development of horticulture on a worldwide scale. The Hungarian R & D will be attentive in the future to manage the accumulated capacities by information and mediating needs and offers to the volonteers of the profession. The reality of the above propositions are amply proved by successes of the Agroinvest Co and of other professionals registered in abroad.
To keep on the top of the world list of the profession we have to follow up the international trends by our permanent presence on the most important centers of administration and production of the world in order to hold on the hot line of the Hungarian administration competent in financing the R & D activities. We need specialists which are open minded, speak languages, familiar with the tricks of informatics, economics and politics, competent in deals, able to make decisions, etc. The education and training should be strenghtened to he conform with those trends. That proposal involves also the need to follow up the activities of the transnational companies, the regular, active participation on international conferences, the permanent attention paid to electronic informations available in the worldwide networks as well as the printed periodicals of horticulture. It is also related to the attraction of investors to the developments aimed within the country as well as abroad. At last but not at least we have to keep in mind that the work performed abroad by the Hungarian professional is a kind of "para-diplomatic mission" which cannot be substituted by any other, sometimes very expensive activity charged on the officia erliplomatic missions. The benefit of it is, however, valid to the whole country because false stereotypes developed during the last 50 years cannot be abolished otherwise.