Showing 4 results for Embryogenesis
R. Fotouhi Ghazvini, Y. Hammidoghli, Y. Ebrahimi,
Volume 5, Issue 2 (7-2001)
Abstract
In order to produce Tristeza virus-free plants from Satsuma mandarin (Citrus unshiu) cultivars (Ishikawa, Sugiyama and Myogawa), unfertilized ovules of plants suspected of CTV (Citrus Tristeza virus), from Mazandaran Mahdasht orchard were cultured on 4 media.
Embryogenesis of nucellus tissue of ovules from Ishikawa and Sugiyama cultivars on MS medium were 31% and 25% and on MT medium from Ishikawa was 40.5%. Unfertilized ovules of Myogawa did not germinate on all media.
Nucellar embryos of Ishikawa and Sugiyama developed on MT+GA3+ME were 83% and 95%, respectively. Embryo differentiation, leaf and plantlet formation were observed on MT+GA3+ADE+ME medium. In the stage of two leaves, the plantlets’ growth under 1500 lux illumination was twice its growth under 800 lux illumination. Budding of in vitro plantlets from both cultivars on susceptible to Tristeza and virus-free seedlings of Key Lime did not show any infection by Tristeza.
R. Fotouhi Ghazvini, S. Shirani,
Volume 6, Issue 2 (7-2002)
Abstract
The effect of different media including the growth regulators on somatic embryogenesis from Mexican lime was studied. The average embryo formation after 60 days from unfertilized ovules in different media was evaluated at 0 to 33.75%. The most effective hormone to stimulate embryogenesis was GA3 at 0.01 and 0.1 mg/l concentrations. Malt extract (ME) at 300 mg/l increased embryo formation, whereas at 1000 mg/l, it inhibited embryogenesis but produced embryogenic callus. Banzyl adenine (BA) at 0.1 and 0.01 mg/l concentrations had significant effects on embryogenesis, while embryo formation was inhibited at high concentrations. Embryo development in different media was also studied. The index of mean root length to mean stem length in the MT3 medium supplemented with 0.1 mg/l of GA3 was observed to be 1.22±0.22, which was regarded a suitable medium for embryo formation, embryo development and plantlet regeneration.
A Habashi, A Mousavi, M Kaviani, S Khoshkam, A Rostami,
Volume 12, Issue 46 (1-2009)
Abstract
Date palm (Phoenix dactylifera L.) is propagated traditionally through offshoots or suckers, which usually appear at or below the ground level surrounding the stem base. However, there are many problems associated with this system. Offshoots are produced in limited number and vegetative propagation through them is slow, laborious, time consuming and expensive. The present study was conducted to determine the best micropropagation protocol for date palm in Kebab, Estameran, Piarom, and Berehi cultivars. The shoot apical meristem from two to three-year-old offshoots was used as source of explants. They were cultured in callus initiation medium, containing different concentrations of 2,4-D (40, 60, 80 and 100 mgl-1), NAA (10 and 20 mgl-1) and 2ip (3 and 5 mgl-1). All cultivars produced high percentage of callus with good quality in a matter of callus friability and color in 100 mgL-1 2,4-D, 20 mgL-1 NAA, and 3 mgL-1 2ip. Kabkab cultivar was superior for callus production (87.25%) in comparison with other cultivars. The calli were then transferred to a proliferation medium and then transferred to somatic embryogenesis medium containing different concentrations of Kinetin (2, 4 and 6 mgL-1), BAP (2, 4 and 6 mgL-1), and NAA (0.1, 0.5 and 1 mgL-1). Somatic embryogenesis was observed in MS medium supplemented with 2 mgL-1 kinetin, 2 mgL-1 BAP, and 0.1 mgL-1 NAA. Kabkab and Estameran cultivars showed higher somatic embryogenesis in comparison with other two cultivars. The somatic embryos were then transferred to MS medium without hormones under light, where they produced shoots and roots. Abbriviations: 2,4-D- 2,4-dichlorophenoxiaceticacid 2ip-N6(2-isopentenyl)adenine NAA-Naphthalene acetic Acid BAP-6-Benzylaminopurine MS-Murashige and skoog (1962).
M Ebrahimi, S.m Khayam Nekoei, S Kadkhodaei,
Volume 12, Issue 46 (1-2009)
Abstract
Somatic embryogenesis is affected by several factors. In this research project, we studied the effect of explant size, wounding and desiccation treatments on somatic embryogenesis and their conversion into plantlet among three genotypes of soybean. The explants were sampled from immature embryos of soybean in three different sizes (3, 5 & 7 mm) with wounding treatment on half of each, and then were cultured on the somatic embryogenesis medium. In order to determine desiccation effect on conversion amount of embryos into plantlets, the produced embryos were affected by three levels of desiccation treatments (2, 4 & 6 days). The increase ratio of callus mean weight, percentage of embryogenic calli, embryo number per explant and percentage of embryo conversion to plantlet were used for treatment evaluation. Variance analysis of the data showed significant differences (P<0.01) between treatments regarding the variables. The results indicated that BP was a superior genotype with embryogenic capability (24.19 %) and the best explant size for somatic embryogenesis was immature embryo with 3 mm length. The six day desiccation treatment caused highest percentage of embryo conversion into plantlet (74.7 %). Wounding increased callus production on explants and number of embryos per explant (20.28), but it did not show any significant effect on percentage of embryogenic calli. Germinated somatic embryos were transferred to pots containing peat-moss. Somatic embryogenesis is an efficient method for the plant regeneration and genetic transformation. However, this method still offers low percentages of plant regeneration, and is perhaps related to the maturation process and high morphological abnormalities of the matured embryos. This study aimed to find some solutions for soybean somatic embryogenesis problems.
