An evaluation of Factors Determining Vitro Flowering of Embryo Derived Shoot of Oil Palm (Elaeis guineensis)

Flowering is an important resulted from expandable of floral organs. In this particular study in vitro flowers were well developed from embryo derived shoot of oil palm (EDS) after 6 months on WPM medium containing 8 mg-l α-naphthalene acetic acid in combination with 12 mg-l Paclobutrazol with high concentration of sucrose (8%) and medium was subsequently subcultured every monthly prolonged to 6 months produced in vitro floral induction (10.2%). An early model due to precocious flowering on EDS of oil palm were occurred if there were long continued subculture for 6 months in the same culture medium whereas PGRs and Sucrose were beneficially contributed on regenerative organ regeneration. In the previous study histological examination has been made on the flowers produced by the inflorescence meristem revealed that these flowers were not true flowers. These flower-like structures were not found to have any reproductive structures and only contained bracts. This impacted that in vitro, under high sucrose and high concentration of NAA growth condition, the conversion of inflorescence meristem to a floral meristem is serious barier and being top priority concern among biotechnologist. The ability to control flowering will be feasible economically contributed to the oil palm industry and being recommended before exerted to the farmers.

Cytokinins and coconut water promoted abnormalities in zygotic embryo culture of oil palm

Induction of adventitious shoot formation from mature zygotic embryo of oil palm was carried out in liquid MS mediumsupplemented with various types of cytokinins. Kinetin (KN) alone at concentration of 0.5 mg/l gave the highest adventitiousshoot formation at 13.4%. However, abnormal shoots in form of inflorescence-like structure (ILS) were obtained in 5mg/l KN containing medium. For coconut water a big ILSs were formed at 10.6%. Histological studied revealed that thoseinflorescences had no clear floral organs

Effect of genotypes of oil palm as indicator for speed of callus and embryogenic callus formation

. Effect of genotypes of oil palm as indicator for speed of callus and embryogenic callus formation. Journal of Agricultural Technology 4(2): 147-156. Among sixteen crosses of immature zygotic embryo was investigated for their effects on callus and embryogenic callus formation. Immature zygotic embryos were excised and cultured on Murashige and Skoog (MS) medium supplemented with 2.5 mg/l dicamba (3, 6-dichloro-oanisic acid). The cultures were placed under light conditions at 14 h photoperiod, 27±1 o C for 3 months. The results revealed that the highest percentage of callus formation (33.33) was obtained from cross number 7 and percentage of embryogenic callus formation (18) was obtained from cross number 14. The highest number of embryogenic callus formation per explant (15.795) was obtained from cross number 16 after 3 months of culture. Callus initiated from these embryos within 4-5 weeks and classified into 4 types; compact, friable, nodular and root-like structure. The highest increment in callus size (1.17 cm) was obtained from cross number 16. In case of the speed index of callus and embryogenic callus formation, cross 16 gave the highest of both parameters at 35.5 and 20.17, respectively

In vitro seed germination and plantlet regeneration of Vanilla siamensis: an endemic species in Thailand

This study reports the in vitro germination of self-pollinated pod of Vanilla siamensis, native to Thailand. The aim of the present work is to determine the effect of culture media and plant growth regulators on seed germination and plantlet regeneration. The vanilla seeds were asymbiotically germinated on different culture media under aseptic conditions. The results showed that, New Dogashima medium (NDM) supplemented with 2% (w/v) sucrose, 15% (v/v) coconut water (CW) and 0.7% (w/v) agar gave the highest levels of seed germination at 10.1%. The fastest and highest percentage seed germination was achieved using NDM supplemented with 2 mg/l gibberellic acid (GA3). Seeds on this culture medium germinated within 7–8 weeks in comparison with 10–11 weeks on culture medium without plant growth regulators. Protocorms were transferred to different culture media with various concentrations of 6- benzyladenine (BA) to assess the protocorm development. The results revealed that 1⁄2 Murashige and Skoog (1⁄2 MS) medium gave the higher result in survival rate of protocorm than NDM. 1⁄2 MS medium with 0.5 mg/l BA was suitable for shoot formation. Plantlet development was completed after subculturing on 1⁄2 MS medium supplemented with 0.5 mg/l α-naphthaleneacetic acid (NAA) for 8 weeks and successfully acclimatized at 91.7%. The protocol outline here can be used for mass propagation of this endangered species and used as a guideline for improvement of V. siamensis and its in vitro conservation

The effect of Agrobacterium densities and inoculation times on gene transformation efficiency in rubber tree

Rubber tree belonging to the genus Hevea is an economically important crop of Thailand and South-east Asia. To optimize its agronomical trait for glyphosate-resistant, in vitro gene transformation through Agrobacterium tumefaciens was investigated. The bacteria carrying plasmid pCAMBIA 1304, harboring gus as screenable marker genes and EPSPs gene was used. The shoot tips were immersed in A. tumefaciens suspension at optical densities (OD600) at 0.3, 0.6 and 0.9 for various times (15, 30 and 60 min). The results revealed that shoot explants immersed in A. tumefaciens suspension at OD600 of 0.6 for 30 min gave the higher survival rate after being cultured on glyphosate containing MS medium for one and half months. Assessment of transformed shoots revealed positive results in GUS histochemical assay. The presence of the gus and EPSPs genes in transformed rubber tree were confirmed by polymerase chain reaction (PCR) technique, dot blot hybridization and Southern PCR hybridization. Specific primers for the gus and EPSPs genes were designed to amplify a 919 and 1,600 bps DNA fragment, respectively.Keywords: Transgenesis, glyphosate, inoculation time, Agrobacterium density, HeveaAfrican Journal of Biotechnology, Vol 13(23) 2321-232

Factors affecting proliferation and elongation of shoots of Phak Liang (Gnetum gnemon Linn.) through tissue culture technique

The tissue culture of Phak Liang (Gnetum gnemon Linn.) was investigated for micropropagation. The types of explant, culture media, types and concentrations of plant growth regulators, orientation of explant and section of explant were tested for their efficacy in inducing and proliferating shoot buds. The elongation of shoots and root induction was also studied. Young leaves gave the highest number of shoot buds when they were cultured in Murashige and Skoog (MS) medium supplemented with 0.25 mg/l IBA and 1.53 mg/l BA. The medium supplemented with 0.25 mg/l thidiazuron (TDZ) alone provided the best result on multiple shoot bud induction both in percentage of explant forming shoots and number of shoot buds per explant. The percentage of explant forming shoot buds and number of shoot buds obtained from leaves were 90% and 26.50 shoot buds, while those from stems were 96.25% and 23.00 shoot buds, respectively. One hundred percent friable callus was induced from stem explant in the same medium supplemented with 1.0 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D) after 2 months of culture. Culturing whole leaf in the position of dorsal contact with medium gave the best multiple shoot bud formation of 92% and 23.00 shoot buds/explant. Cutting stem into half and culturing in horizontal position gave the best multiple shoot bud formation of 96% and 23.00 shoot buds/explant after culture for 2 months. The best elongation of shoot buds (2.54 shoots) derived from cultured leaves was induced in the liquid medium. While stem-derived shoot buds (3.45 shoots) was induced in the solid medium of the same medium components. However, root could not be induced from elongated shoots

Early fruit setting from tissue culture-derived mangosteen tree

Vitro-plantlets of mangosteen derived from culturing young leaves were acclimatized in 1993. Small and large polybag seedlings were carefully raised under controlled environmental conditions until 1994 when they were ready to be transferred to the field. During this stage, morphological abnormalities of the seedlings were recorded. After transferring to the field for 5-6 years (1994-1999) at Yi Ngo District, Narathiwat Province and Klong Hoi Khong District, Songkhla Province, morphological characters of the plants were again observed in comparison with seed-derived plants. The results showed that tissue culture-derived plants were more bushy and started blooming 5 years after planting while the seed-derived plants still had tall canopy (not bushy) and were not bearing fruit in the same period of time. However, the blooming of cultured plants did not give the fruit setting in the first blooming year. All flowers dropped off completely. Heavy fruit setting was observed in the following year (2000). Tissue culture trees had smaller but healthier leaves whereas seed-derived trees had pale yellowish green leaves. Fruit qualities in terms of total soluble solids (TSS) and total acids (TA) were not much different between the two types of these mangosteen trees