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

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

Plantlet regeneration and somaclonal variation in Anthurium cv. Sultan through embryogenesis

Calli of anthurium cv. Sultan were cultured on liquid or solid MMS (modified Murashige and Skoog) medium. The solid medium was supplemented with 1.0-4.0 mg/l 2,4-D (2,4-dichlorophenoxyacetic acid) incombination with 0.5 and 1.0 mg/l kinetin or 0.5, 0.75 and 1.0 mg/l TDZ (thidiazuron) with 0.5 and 1.0 mg/l BA (N6-benzyladenine) for 16 weeks. The result showed that a cluster of embryogenic callus (1.3-1.5 cm)was formed on medium with 2.0 mg/l 2,4-D and 0.5 mg/l kinetin (90%) and developed into shoot and shoot with root (83.3% and 100%, respectively). The solid medium with 1.0 mg/l TDZ and 1.0 mg/l BA gave66.67% embryogenic callus formation after culturing for 12 months. Liquid medium supplemented with 3.0 mg/l 2,4-D and 0.5 mg/l BA gave the best fresh weight of embryogenic callus (3.33 g). Regenerants obtainedfrom BA and TDZ containing solid medium produced abnormal lanceolate leaves. Isozyme markers revealed different pattern of esterase activity in normal and abnormal leaves

Some Boletes of Thailand

The objective of this study was to collect and identify some Boletes of Thailand. Through periodical excursions in woodland area in the north, northeast and south of Thailand, and regular visits to markets inthe areas during 1995-2005, 20 species of Boletes were collected and identified. These were Boletellus ananas (M.A.Curtis) Murrill, Boletellus emodensis (Berk.) Singer, Boletellus sp. 1, Boletellus sp. 2, Boletellus sp. 3,Boletinus sp., Boletus griseipurpureus Corner, Boletus bicolor Peck, Boletus nanus (Massee.) Singer, Boletus sp. 1, Boletus sp. 2, Boletus sp. 3, Heimiella retispora (Pat. & C.F. Baker) Boedijn, Phlebopus colossus (R.Heim) Singer, Phylloporus pelletieri (Lev.) Quel., Pulveroboletus ravenelii (Berk. & M.A.Curtis) Murrill, Pulveroboletus sp., Strobilomyces confusus Singer, Strobilomyces floccopus (Vahl) P. Karst., and Tylopilusalbo - ater (Schwein) Murrill

Effect of seasonal collection on callus Induction, proliferation and somatic embryogenesis from anther cultures of Heveabrasiliensis MuellArg

Hevea brasiliensis that is grown in Thailand and Southeast Asia is a very valuable source of natural rubber. However, few studies have been conducted to evaluate the effects of seasonal effect on plantlet regenera-tion through somatic embryogenesis from anther culture. Thus, this study discussed the effect of season on callus induction subsequent to plantlet regeneration from culturing of anther. Male flowers were aseptically opened and anthers were excised to culture on callus induction medium (CIM) which was MS supplemented with 5% sucrose, 1 mg.L-1 2,4-D, 1 mg.L-1 KN, 1 mg.L-1 NAA. Somatic embryo (SE) developed on MS medium supplemented with 3% sucrose, 0.2 mg.L-1 NAA, 1 mg.L-1 BA, 3 mg.L-1 KN and 0.05 mg.L-1 GA3. This medium is so called embryo induction medium (EIM).Anther collectedfrom different season gave different result in callus induction, proliferation and somatic embryogenesis, healthy anther collected in February 15, 2013 gave the best result in callus induction (86.25%), proliferation (422 mgFW) and somatic embryogenesis (20%). Complete plantlets (15.63%)were obtained on MS medium supplemented with 5% sucrose, 0.5 mg.L-1 KN, 0.2 mg.L-1 IAA, 1 mg.L-1 BA, 0.3 mg.L-1 GA3 and 0.2% phytagel. Seasonal collection plays influence rolein successful somatic embryogenesis in tissue culture of rubber tree.Keywords: Hevea brasiliensis, rubber, antherculture, callus induction, seasonal collection, somatic embryogenesis.African Journal of Biotechnology, Vol 13(31) 3560-356

The growth of Neck orange (Citrus reticulata Blanco) scion on seedling and cutting of trifoliate orange hybrid rootstocks

The growth of Neck orange (Citrus reticulata Blanco) on seedling and cutting of trifoliate orange hybrid rootstocks was studied at the Department of Plant Science, Faculty of Natural Resources, Prince of Songkla University in order to select the appropriate rootstock. The stem cross section, growth characteristic and isozyme pattern of Neck orange scion were investigated. One-year-old seedlings and cuttings (both with 0.3-0.4 mm stem diameter) of Troyer citrange, Swingle citrumelo and Neck orange were used as root stock for grafting with Neck orange scions. The diameter of upper and lower graft union, number of branches and leaves, height, root length, shoot and root dry weight and shoot: root dry weight ratio of grafted plants were measured at 24 weeks after grafting. The results showed that the structure of stem cross section of Troyer citrange and Neck orange i.e. the size of periderm, vascular bundle and pith, were similar to that of Neck orange. The vascular bundle of Swingle citrumelo was larger than that of the two rootstocks. Troyer citrange rootstock gave the best results in all growth parameters of Neck orange. The study of isozymes recorded an extra locus (Est 3) of Swingle citrumelo rootstock occurred in Neck orange at 24 and 48 weeks after grafting