Effect of gelling agents on in vitro development of Amelanchier canadensis ‘Rainbow Pillar’

In vitro shoot multiplication responses of Amelanchier canadensis ‘Rainbow Pillar’ were studied on media solidifi ed with differentgelling agents. The media were gelled either with 6.8 g l-1 fi brous agar-agar, or 50.0 g l-1 wheat starch, or 20.0 g l-1 Guar gum, or 15 g l-1 Isubgolor 50.0 g l-1 wheat starch mixed with 0.5 g l-1 Phytagel. Shoot cultures were grown for two months, thereafter the multiplication rates (numberof newly developed shoots per explant) were counted and the length of shoots were measured. We found that the highest shoot multiplicationof Amelanchier canadensis ‘Rainbow Pillar’ occurred on media gelled with Guar gum, while the longest shoots developed on media withStarch. About four-fold shoot number were obtained on media with Guar gum compared to the weakest results found on media gelled withIsubgol. Finally, considering all factors (shoot growth parameters, costs) the most economical gelling agent for Amelanchier canadensis‘Rainbow Pillar’ was proved to be wheat starch among the tested alternatives which allows a 75.6% cost reduction

Effect of gelling agents on in vitro development of Amelanchier canadensis ‘Rainbow Pillar’

In vitro shoot multiplication responses of Amelanchier canadensis ‘Rainbow Pillar’ were studied on media solidifi ed with different gelling agents. The media were gelled either with 6.8 g l-1 fi brous agar-agar, or 50.0 g l-1 wheat starch, or 20.0 g l-1 Guar gum, or 15 g l-1 Isubgol or 50.0 g l-1 wheat starch mixed with 0.5 g l-1 Phytagel. Shoot cultures were grown for two months, thereafter the multiplication rates (number of newly developed shoots per explant) were counted and the length of shoots were measured. We found that the highest shoot multiplication of Amelanchier canadensis ‘Rainbow Pillar’ occurred on media gelled with Guar gum, while the longest shoots developed on media with Starch. About four-fold shoot number were obtained on media with Guar gum compared to the weakest results found on media gelled with Isubgol. Finally, considering all factors (shoot growth parameters, costs) the most economical gelling agent for Amelanchier canadensis ‘Rainbow Pillar’ was proved to be wheat starch among the tested alternatives which allows a 75.6% cost reduction

How to produce large sized microtubers of potato cv. Desiree

In vitro tuberization was induced on explants with different number of nodes layered on a medium with high sucrose (8%) content: 30, 15, 10, 7 and 6 explants per jar were cultured containing 1, 2, 3, 4 or 5 nodes, respectively. Microtubers developed were graded by their smallest diameter, and the number of tubers per jar, their size distribution, their fresh weight and the multiplication rate were recorded. The highest multiplication rate (1.98) was obtained for explants with 5 nodes. The size distribution of tubers was markedly affected by treatments. The majority of microtubers (49.4%) were 6-8 mm in the case of the smallest explants (with I node). When explants with 2 to 5 nodes were used, the most microtubers were 8-10 mm but with an increase of explant size, more and more microtubers were produced with larger diameter up to 16 mm and average fresh weight of tubers also increased with the increase of explant size. For the microtuber production of Desiree the use of explants with two nodes can be suggested because in this treatment the average fresh weight of microtubers was high enough (250 mg) and the number of large sized microtubers was very high (79% was larger than 6 mm and 53% was larger than 8 mm)

How to produce large sized microtubers of potato cv. Desiree

In vitro tuberization was induced on explants with different number of nodes layered on a medium with high sucrose (8%) content: 30, 15, 10, 7 and 6 explants per jar were cultured containing 1, 2, 3, 4 or 5 nodes, respectively. Microtubers developed were graded by their smallest diameter, and the number of tubers per jar, their size distribution, their fresh weight and the multiplication rate were recorded. The highest multiplication rate (1.98) was obtained for explants with 5 nodes. The size distribution of tubers was markedly affected by treatments. The majority of microtubers (49.4%) were 6-8 mm in the case of the smallest explants (with I node). When explants with 2 to 5 nodes were used, the most microtubers were 8-10 mm but with an increase of explant size, more and more microtubers were produced with larger diameter up to 16 mm and average fresh weight of tubers also increased with the increase of explant size. For the microtuber production of Desiree the use of explants with two nodes can be suggested because in this treatment the average fresh weight of microtubers was high enough (250 mg) and the number of large sized microtubers was very high (79% was larger than 6 mm and 53% was larger than 8 mm)

Effects of tuberization conditions on the microtuber yield and on the proportion of microtuber tissues

The production facilities of large-sized microtubers in three potato varieties (cv. Desiree, BorO, Gfilbaba) and the effects of the applied tuberization conditions on the proportion of microtuber tissues, especially on the perimedullary region were investigated in present work. In vitro tuberization was induced on explants with 2 or 5 nodes layered on MS medium supplemented with 8% sucrose. Induced cultures were exposed to short days (8 h) for 2 weeks, then to total darkness for further 11 weeks. For volume calculations of different tissue regions, the formula for ellipsoids (V=4/37c1/8/w2) was used. The number of large-size tubers (> 8 mm, up to 16 mm) reached 53%, 59% and 44% in cvs. Desiree, Giilbaba and Bore, respectively, which indicate that the size of microtubers could be increased by appropriate sucrose support and explant type. Microtubers produced on hormone-free medium have well-developed perimedullary region, and its volume rate seemed to be important in the final size of tubers. The increase in the rate of volume of the perimedulla was connected to the increase of tuber size until tubers reached 12 mm diameter. In microtubers larger than 12 mm in diameter, the volume rate of the pith was increased

Inhibition and recovery of germination and growing ability of seedlings under and after osmotic stress induced by polyethylene glycol in 8 pea genotypes

Germination and early seedling growth of eight pea genotypes were examined under and soon after different (5%, 10%, 15%, and 20%) PEG treatments. Seeds were germinated on PEG solution for 3 or 6 days and then further germinated and cultured on filter paper moistened by water for 3 and 6 days. The length and fresh weight of shoots and roots of seedlings were measured and used for evaluation of genotypes. Roots were less inhibited by osmotic stress than shoots similarly to other plant species. The variability among the genotypes was the greatest in the case of shoot growth at 5% PEG treatment and in the case of root growth at 15% PEG treatment. Results suggest that growing responses of genotypes after cessation of stress are more suitable for the evaluation of their osmotic tolerance, than their responses expressed during in vitro stress conditions. Genotypes with relatively high or low osmotic stress tolerance, respectively, could be distinguished with 6 days after recovery from 3-day-long 15% PEG treatment concerning the rate of shoot weight to root weight

Inhibition and recovery of germination and growing ability of seedlings under and after osmotic stress induced by polyethylene glycol in 8 pea genotypes

Germination and early seedling growth of eight pea genotypes were examined under and soon after different (5%, 10%, 15%, and 20%) PEG treatments. Seeds were germinated on PEG solution for 3 or 6 days and then further germinated and cultured on filter paper moistened by water for 3 and 6 days. The length and fresh weight of shoots and roots of seedlings were measured and used for evaluation of genotypes. Roots were less inhibited by osmotic stress than shoots similarly to other plant species. The variability among the genotypes was the greatest in the case of shoot growth at 5% PEG treatment and in the case of root growth at 15% PEG treatment. Results suggest that growing responses of genotypes after cessation of stress are more suitable for the evaluation of their osmotic tolerance, than their responses expressed during in vitro stress conditions. Genotypes with relatively high or low osmotic stress tolerance, respectively, could be distinguished with 6 days after recovery from 3-day-long 15% PEG treatment concerning the rate of shoot weight to root weight

New in vitro micrografting method for apple by sticking

The requirements for in vitro micrografting in apple are described. In vitro multiplicated shoots of cv. Royal Gala were the sources of rootstocks and scions after different pre-treatment, respectively. Oxidative browning of cut surfaces could be inhibited by the use of antioxidant mixture during grafting process. Scion base cut in v-shape was stuck by 1% agar-agar solution into the vertical slit of rootstock. There was no any displacement and the rate of fused and further developed grafts was 95 percent. Agar-agar between the rootstock and scion made the transport of different materials possible and hold the graft units together until the fusion took place. Fusion was proved also by histological studies. Some of in vitro micrografts were planted and acclimatisated and the survival was 100 percent

Model experiments for establishment of in vitro culture by micrografting in apple

Micrografting was used in our experiments for establishment of in vitro culture from one rootstock (`JTE-F') and three scion cultivars (`Remo', 'Rewena' and `Reanda') of apple. Shoot tips of these cultivars were harvested from field and grafted onto in vitro rootstock cultivars. Their survival and development were studied. 42-93% of shoot tips survived and developed further depending on cultivar. Impermanent browning of sticking agar-agar could be observed in 21-25% of the micrografts depending on cultivars but discolouration of agar-agar ceased within one week and did not cause any death of shoot tips. We used micrografting successfully for establishment of in vitro culture from cultivars, from which earlier with conventional methods the culture establishment was not possible because of hard tissue browning. However, further studies are necessary to ensure the survival and development of shoots after removing them from micrografts

New in vitro micrografting method for apple by sticking

The requirements for in vitro micrografting in apple are described. In vitro multiplicated shoots of cv. Royal Gala were the sources of rootstocks and scions after different pre-treatment, respectively. Oxidative browning of cut surfaces could be inhibited by the use of antioxidant mixture during grafting process. Scion base cut in v-shape was stuck by 1% agar-agar solution into the vertical slit of rootstock. There was no any displacement and the rate of fused and further developed grafts was 95 percent. Agar-agar between the rootstock and scion made the transport of different materials possible and hold the graft units together until the fusion took place. Fusion was proved also by histological studies. Some of in vitro micrografts were planted and acclimatisated and the survival was 100 percent