A comparative study on the effects of ultrasound and some growth factors on somatic embryogenesis and artificial seed production in cucumber (Cucumis sativus L.)

Cucumber (Cucumis sativus L.), a popular vegetable crop of the family Cucurbitaceae, is cultivated in different parts of the world and is of great economic importance. Ultrasound is known as a physical stimulus that can affect living systems. At the right frequency and exposure period, these waves have desired effects. In the present study, 2-week-old plants, were put in an ultrasonic bath with a nominal frequency of 40 kHz, a central frequency of 34/722 kHz and a bandwidth of 320 Hz for 0, 5, 10 and 15 minutes. Hypocotyl pieces were used as explants and cultured in Murashige and Skoog medium supplemented with 0/5 mg/l each of 2,4-dichlorophenoxyacetic acid, 1-Naphthalene acetic acid, kinetin and 6-benzylaminopurine. The use of ultrasonication at a nominal frequency of 40 kHz for 10 minutes showed better results as compared with the samples treated for 0, 5 and 15 minutes, in terms of the shape, maturity of the embryos, and also the germination of artificial seeds and maturing to flowering stage. Since the cucumber of Esfahan is very famous for its aroma and taste and it is somewhat at risk of extinction, we studied the production of artificial seeds of this valuable plant using somatic embryos and apical buds. This research is the first report on investigation of the positive effect of ultrasound on somatic embryogenesis and artificial seed production. our results clearly showed that this method is a practical method to accelerate seed germination and flowering stage.

Artificial seed production of Pangasiid catfish in the Mekong Delta, Vietnam.

The two pangasiid catfish, Pangasius bocourti and P. hypophthalmus, are widely cultured in the Mekong Delta, Vietnam. However, seed supply until recently was dependent on fry and fingerlings caught from the Mekong River. In 1994, a research programme was carried out on artificial seed production of these two species in captive conditions. In 1995, about 30,000 fingerlings were first produced in An Giang and Can Tho provinces and a proper technique of induced breeding, progressive human chorionic gonadotropin (hCG) treatment, was determined. This technique, involving two steps of hCG injections, successfully induced ovulation in 66% of 67 treated females of P. bocourti. Application of this technique to other pangasiid catfish species such as P. conchophilus, P. hypophthalmus, P. mekongensis, and P. larnaudii also resulted in breeding success. Research on larval rearing has also been conducted to improve the growth and survival of pangasiid larvae. Extension of research findings of induced breeding and larval rearing has allowed mass seed production of pangasiid catfish in the Mekong Delta.

PEMIJAHAN SEMI-BUATAN SIPUT GONGGONG, Laevistrombus turturella DENGAN INDUKSI KOMBINASI HORMON LHRH-a DAN ANTIDOPAMIN

Gonggong adalah sejenis siput laut yang merupakan makanan laut (seafood) favorit dan ikon Kota Tanjungpinang, ibukota Provinsi Kepulauan Riau (Kepri). Gonggong mengandung protein tinggi, yaitu sekitar 46,65%. Tidak ada laporan tentang produksi budidaya dan upaya konservasi gonggong. Teknologi produksi benih buatan gonggong belum berkembang. Tujuan penelitian ini adalah untuk mengevaluasi pemberian kombinasi hormon LHRH-a dan antidopamin untuk menginduksi proses pemijahan. Evaluasi pemberian hormon LHRH-a dan antidopamin pada pemijahan siput gonggong dilakukan dengan empat dosis: 0,5 ìLgι bobot badan lunak (BB) (P1); 0,7 ìLgι BB; dan 0,9 ìLgι BB (P2); dan tanpa suntikan (TS). Siput gonggong pascasuntikan dipelihara di akuarium selama 14 hari. Hasil penelitian menunjukkan bahwa (1) kombinasi hormon LHRH-a dan antidopamin mampu merangsang pemijahan gonggong. Dosis rendah hormon LHRH-a dan antidopamin (P-1) menghasilkan induk betina yang memijah paling banyak, yaitu 34,48%; lebih tinggi dari P-2 (27,59%), P-3 (20,69%); dan TS (17,24%); (2) jumlah telur yang dikeluarkan oleh induk betina berbeda secara signifikan antar perlakuan (P<0,05). Jumlah telur yang dikeluarkan oleh masing-masing induk berkisar antara 10.874-63.489 butir/ekor dengan rata-rata 39.347 ± 16.667 butir/ekor.The gonggong is a species of sea conch which is a favourite seafood and an icon of Tanjungpinang City, capital of Kepulauan Riau (Kepri) Province. Gonggong contains high protein, about 46.65%. There were no reports on aquaculture production and conservation effort of gonggong. The technology on artificial seed production of gonggong has not yet developed. The aim of this study was to evaluate the administration of LHRH-a hormone and anti-dopamine to induce the spawning process. Evaluation of the administration of LHRH-a hormone and anti-dopamine on the gonggong conch’s spawning was carried out with four doses: 0.5 ìLgι soft body weight (BW) (P-1), 0.7 ìLgι BW; and 0.9 ìLgι BW (P-2); and without injections (TS). The gonggong conchs after injection were reared in aquarium for 14 days. The results showed that (1) a combination of LHRH-a hormone and anti-dopamine was able to stimulate gonggong spawning. The lower dose of LHRH-a hormone and anti-dopamine (P-1) produced the highest number of spawned female broodstock, which was 34.48%, higher than P-2 (27.59%), P-3 (20.69%), and TS (17.24%); (2) the number of eggs released by female broodstock was significantly different among the treatments (P<0.05). The number of eggs released by each female broodstock ranges between 10,874-63,489 grains/ind. with an average of 39,347±16,667 grains/ind.

In vitro regeneration protocol for artificial seed production in an important medicinal plant Mentha arvensis L

Context: The application of encapsulated shoot tips and nodal segments may contribute to the protection of rare and threatened medicinal plants. Although the artificial seed technique has been reported for more than two decades, for medicinal plants this method has not been developed sufficiently. The main limitations in conventional propagation of some species with medicinal value are: reduced endosperm, low germination rate and seedless varieties. The above mentioned reasons indicate the need for the production of artificial seeds as a technique which combines the advantages of clonal multiplication with those of seed propagation and storage. Objectives: The objective of the present investigation was to standardize artificial seed production technology taking shoot tip and nodal explants in Mentha arvensis and its in vitro regeneration Materials and Methods: Sodium alginate beads were produced by encapsulation of shoot tip and nodal segments of the plant M. arvensis. MS medium was used as basal medium with agar and sodium alginate was used as gelling agent accompanied by CaCl2 solution. Results: Different concentrations and combinations of BAP, Kin and NAA were used in alginate bead in MS basal medium. Among the different concentrations of phytohormone, highest 80% of shoot formation was observed in MS medium containing 2.0 mg/l BAP + 0.2 mg/l NAA from nodal segments of M. arvensis. Highest average number of shoot 9.87 ± 0.58 formation was obtained in the same medium but highest length of shoot 6.27 ± 0.29 cm was found in the medium having 1.0 mg/l BAP + 0.5 mg/l NAA. Conclusion: The present investigation clearly established and demonstrated the method of obtaining the artificial seed production in M. arvensis supported by different hormone concentrations DOI: http://dx.doi.org/10.3329/jbs.v20i0.17722 J. bio-sci. 20: 99-108, 2012