RAPID MICROPROPAGATION OF VU NU ORCHID (ONCIDIUM SP.) BY USING TISSUE CULTURE TECHNIQUE

: The high demand of Oncidium orchids leads us to find out efficient methods of propagating them. However, the propagation rate of traditional methods are low in nature and a hybrid seed is not genetically stable. Thus, plant cell biotechnology is examined as the most effective way to resolve the barrier of elite clone production. Shoot clusters were cultured on MS medium supplemented with 2,4-D (1 mg/l) for callus induction (76.19%) before induced callus was favoured for PLBs regeneration (98 PLBs/callus cluster) on MS medium supplemented with NAA (0.75 mg/l); the combination of BA (0.5 mg/l) and NAA (0.5 mg/l) was favoured for PLBs regeneration (28.18 PLBs/shoot cluster) from shoots cultivation. The PLBs (79.21 PLBs/PLB cluster) were then proliferated on MS medium supplemented with NAA (1 mg/l) and BA (1 mg/l) for shoot regeneration (12.42 shoots/PLBs cluster). Multiple-shoots were divided to 3-4 shoots/cluster for micropropagation on the MS medium supplemented with the combination of BA (0.25 mg/l) and NAA (0.25 mg/l) to reach 11.66 shoots/cluster. Shoots were finally separated to single-shoot for rooting on the MS medium supplemented with NAA (0.75 mg/l). A scheme for Oncidium micropropagation using PLBs culture techniques was set up.

The effect of cluster thinning, cluster tipping, cluster shredding and defoliation at the flowering on the vegetative and generative vine performance from Kékfrankos Cv.

The cluster thinning is a method of the yield regulation.With the removal one part of the clusters, the yield pro leaf area will be lower, hereby the grape and wine quality will be improved. The regulation of the yield can lead to further advantages: the ratio of the vegetative and generative performance of the vines will improve, the condition of the plants will better, the number of the physiological diseases can be reduced and the growth of the shoots and roots can be promoted. The grape growers make the cluster thinning almost exclusive by creating one cluster shoots. Usually the upper clusters are removed, because the sugar content of these second or third clusters will be lower. The cluster thinning is an easy task, can be done without special skills. It is an effective method improving wine quality, but its use can lead to other problems. The grapes try to compensate the removed clusters. Therefore the clusters will be bigger and thicker, but more sensitive to bunch rot. Moreover the treatment is expensive, because it needs manual work. It is worth to get acquainted and try the new yield regulation methods, which can help to avoid the occurring problems. Our aim is to show the results of our experiment, which was carried out in Eger, examining the red grape cultivar Kékfrankos. During our 4 years long experiment we compared the effects of cluster thinning, cluster shredding, cluster tipping and defoliation at the flowering, on the vegetative and generative vine performance.