A comparison of callus induction in 4 Garcinia species

Background: This research is intended to determine suitable types and concentrations of plant growth regulators (PGRs) to induce callus on stem and leaf sections of 4 species of the genus Garcinia, namely, Garcinia mangostana, Garcinia schomburgkiana, Garcinia cowa, and Garcinia celebica. The base medium was MS medium containing 30 g l -1 sucrose, 0.5 g l-1 polyvinylpyrrolidone (PVP), and 7 g l-1 agar, and for the different treatments, PGRs were added to the medium as follows: thidiazuron (TDZ) at concentrations of 0, 0.1, 0.5, 1, and 2 mg l-1; 6-(3- hydroxybenzylamino) purine (meta-topolin) at concentrations of 0, 0.5, 2.5, and 5 mg l-1; 4-amino-3,5,6- trichloro-2-pyridinecarboxylic acid (picloram) at concentrations of 0, 0.5, 2.5, and 5 mg l-1; and 2,4- dichlorophenoxyacetic acid (2,4-D) at concentrations of 0, 0.5, 1, 2, and 4 mg l-1. The occurrence of callus was observed after 4 weeks. Results: A maximum of 100% and 93% of G. mangostana leaf explants formed callus in the 0.5 mg l-1 and 1 mg l-1 TDZ treatments, respectively, while 100% of G. schomburgkiana stem explants formed callus in the 1 mg l-1 TDZ treatment and 89% of G. schomburgkiana leaf explants formed callus in the 0.5 mg l-1 picloram treatment. The highest callus induction rate for G. cowa was 62% in the 1 mg l-1 TDZ treatment and for G. celebica was 56% in the 0.5 mg l-1•mT-1 treatment. Conclusions: For all 4 species, the greatest amount of large nodular callus was observed in the TDZ treatments. White, friable callus was observed on most of the 2,4-D and picloram treatment groups. Most meta-topolin treatments resulted in minimal callus formation.

A comparative study of karyomorphology among three populations of Garcinia indica (Clusiaceae) (Thomas-Dupetite) Choisy.

Garcinia indica is a tree species of the family Clusiaceae. This species is endemically distributed only in Ratnagiri and Sindhudurga district of Maharashtra. Plants collected in particularly Dive Agar and Sawantwadi show morphological variations. Mitotic chromosomes from three different population from the Konkan region were studied using propionic orcein stain. Chromosome numbers 2n = 54 is reported for all the populations. Three populations differed from each other in some aspects. Karyotype analysis showed that Deorukh population from Ratnagiri region showed one pair of satellite and one pair of secondary constrictions while Otawane population from Sawantwadi showed one satellite chromosome but differ in pattern of secondary constriction. Third, Diveagar population from Raigad district showed three pairs of satellite chromosomes and one pair of secondary constriction. So, it can be concluded that, plants from Bapat Garden of Dive Agar and Otawane region can be considered as cytotypes.

De novo shoot regeneration from root cultures of Garcinia indica Choiss.

Roots of plantlets of Garcinia indica when cultured for long time on half strength MS medium supplemented with BAP (0.44-2.22 microM) showed production of de novo shoots. Roots attached to mother plant showed more number of shoots, while excised root segments produced lesser shoots. Shoots (0.5-0.8 cm) were transferred to elongation medium consisting of Woody Plant Medium (WPM) supplemented with BAP (4.44-22.69 microM), IAA (5.71 microM) and kinetin (4.65 microM). It was observed that shoot length increased to 1-2 cm. WPM medium supplemented with NAA (2.69-10.74 microM) and IBA (4.90 microM) induced rooting within 20-25 days. Using the present protocol, 20-25 plantlets could be regenerated from single root explant within 3 to 4 months. The protocol has potential for large scale production of elite plants.

Raíz secundaria embrional asociada a la germinación de Garcinia intermedia (Clusiaceae) y su posible papel en la supervivencia de las plántulas / Secondary embryonary root associated with seed germination in Garcinia intermedia (Clusiaceae) and its possible role in seedling survival

Germination tests on Garcinia intermedia (Clusiaceae) seeds showed the growth of two types of roots: additionally to the primary root, a secondary root crosses the seed lengthwise. To determine its possible role on the survival and growth of this species, 90 seedlings at least six months old (collected in Central Costa Rica) were planted in plastic bags with organic soil, and placed in a greenhouse. The seedlings were treated as follows: treatments in which the primary or secondary root was cut off, and a control group with both roots intact (30 replicates each). After three months 10 seedlings/month/treatment were extracted to measure their height, basal diameter, root length (main and secondary root), and biomass of the stem, roots and seed (without its coat). Control seedlings had the highest growth, followed by those without secondary roots. Nonetheless, more than 90% of the seedlings whose primary roots were cut off, survived after five months of the excision treatment, in part due to the capacity of this species to regenerate its radical system through the seed reserves, sprouting of a primary-like root, and/or the growth stimulus of the secondary root (60% of the total: 20% with sprouts from the primary root stump, 13.3% with a growth stimulus of the secondary root, and 26.7% with both conditions). The length of the sprouted roots was significantly different only on those plants that were extracted during the first two monthly measurements, when compared with the control (F6 = 18.6, F7 = 16.0, p < 0.01).

[Secondary embryonary root associated with seed germination in Garcinia intermedia (Clusiaceae) and its possible role in seedling survival]. / Raíz secundaria embrional asociada a la germinación de Garcinia intermedia (Clusiaceae) y su posible papel en la supervivencia de las plántulas.

Germination tests on Garcinia intermedia (Clusiaceae) seeds showed the growth of two types of roots: additionally to the primary root, a secondary root crosses the seed lengthwise. To determine its possible role on the survival and growth of this species, 90 seedlings at least six months old (collected in Central Costa Rica) were planted in plastic bags with organic soil, and placed in a greenhouse. The seedlings were treated as follows: treatments in which the primary or secondary root was cut off, and a control group with both roots intact (30 replicates each). After three months 10 seedlings/month/treatment were extracted to measure their height, basal diameter, root length (main and secondary root), and biomass of the stem, roots and seed (without its coat). Control seedlings had the highest growth, followed by those without secondary roots. Nonetheless, more than 90% of the seedlings whose primary roots were cut off, survived after five months of the excision treatment, in part due to the capacity of this species to regenerate its radical system through the seed reserves, sprouting of a primary-like root, and/or the growth stimulus of the secondary root (60% of the total: 20% with sprouts from the primary root stump, 13.3% with a growth stimulus of the secondary root, and 26.7% with both conditions). The length of the sprouted roots was significantly different only on those plants that were extracted during the first two monthly measurements, when compared with the control (F6 = 18.6, F7 = 16.0, p < 0.01).

Phenolic compounds from the fruit of Garcinia dulcis.

Dulcinoside (1), dulcisisoflavone (2), dulcisxanthone A (3) and sphaerobioside acetate (6) together with 22 known compounds were isolated from the green fruit of G. dulcis. Dulcisflavan (4), dulcisxanthone B (5) and isonormangostin (7) together with 22 known compounds were isolated from the ripe fruit. Compounds 6 and 7 were synthetic known compounds. Their structures were determined by spectroscopic methods. The radical scavenging and antibacterial activities of some of the compounds were investigated.

[Effect of low nocturnal temperature stress on fluorescence characteristics and active oxygen metabolism in leaves of Garcinia hanburyi seedlings grown under two levels of irradiance].

The fluorescence characteristics and active oxygen metabolism in leaves in Garcinia hanburyi seedlings grown under two irradiance levels (50% and 8% of full natural sunlight) and nocturnal low temperature (4 degrees C) were studied in Xishuangbanna. The results showed that the photochemical efficiency of PS II (Fv/Fm), the quantum yield of PS II linear electron transport (phi PS II) and non-photochemical quenching (NPQ) were decreased, but the initial fluorescence yield (F0) were increased with prolonged stress time of low temperature in leaves of Garcinia hanburyi grown under the two different irradiance levels. After three days of recovery treatment, the Fv/Fm and F0 of Garcinia hanburyi grown under 50% natural irradiance were not recovered completely, while those of the seedlings grown in 8% natural irradiance were recovered almost completely, which indicated that the photosynthetic apparatus of Garcinia hanburyi grown under 50% irradiance was injured by photooxidation, but that of seedlings grown in 8% irradiance was only reversibly inactivated by the nocturnal low temperature stress. In the mean time, although the activities of protective enzymes (SOD, CAT, and APX) increased, the O2-. production rate and H2O2 content also increased with the duration of the stress. The MDA also accumulated in leaves of Garcinia hanburyi grown under two different irradiance levels. After three day's recovery, much less active oxygen was produced in leaves of Garcinia hanburyi grown under 8% than that under 50% irradiance. The implication of the results for practice were also discussed.