Number Of Embryogenic Calli Research Articles

Development and Characterization of Transgenic Sugarcane with Insect Resistance and Herbicide Tolerance.

Genetically modified crops which had been commercial applied extensively majorly are the insect resistance and herbicide tolerance events. In this study, the Bt insecticidal gene Cry1Ab, the glyphosate-tolerant gene EPSPS, and the selection marker gene PMI were combined into a single transferred DNA fragment and introduced into sugarcane by Agrobacterium-mediated transformation. Thirty-three resistant plantlets were obtained after selection using a PMI/mannose selection system. Thirty of these resistant plantlets were PCR positive for the three target genes. Southern blot assay revealed that the copy number of the integrated fragment in the transformed plantlets varied from 1 to 7. ELISA analysis showed that 23 of the 33 resistant plantlets expressed Cry1Ab and EPSPS protein. Five single-copy and ELISA-positive transgenic lines were tested under laboratory and field conditions to determine their resistance to insects and herbicides, and also evaluated their agronomic characteristics and industrial traits. Results showed that larvae fed with fodder mixture containing stem tissues from single-copy transgenic lines were weak and small, moreover, pupation and eclosion were delayed significantly during voluntary feeding bioassays. None of transgenic sugarcane was destroyed by cane borer while more than 30% of wild type sugarcane was destroyed by cane borer. For herbicide resistance, the transgenic plantlets grew healthy even when treated with up to 0.5% roundup while wild type plantlets would die off when treated with 0.1% roundup. Thus demonstrate that these transgenic lines showed strong insect resistance and glyphosate tolerance under both laboratory and field conditions. But in the field most of the transgenic plants were shorter and more slender than non-transformed control plants. So they presented poor agronomic characteristics and industrial traits than non-transformed control plants. Thus, a considerable number of embryogenic calli should be infected to obtain transgenic lines with potential for commercial use.

Somatic embryogenesis and plant regeneration in glandless upland cotton (Gossypium hirsutum L.)

Glandless upland cotton has an important economic value. Embryogenic calli and regenerated plants were obtained from the hypocotyl explants of glandless upland cotton seedlings, cultivar Jisheng1. The results indicated that somatic embryogenesis was significantly influenced by the types of auxin and cytokinin. 2, 4-D was advantageous to induce cotton callus, but embryogenic callus could not be obtained on the 2, 4-D medium. Embryogenic calli were also not obtained on the MSB sold medium with the combination of IBA and BA. However, embryogenic calli were induced when the hypocotyl explants were cultured on the IBA and KT medium. More than 31% of the hypocotyl segments produced embryogenic calli when the MSB medium was supplemented with 1.0 mg·L−1 IBA and 0.5 mg·L−1 KT. Embryogenic calli with somatic embryos could be observed within three months. Somatic embryo germination and maturation occurred on the hormone-free MSB medium with 1.0 g·L−1 Gln and 0.5 g·L−1 Asn. A number of regenerated plants could be obtained in six months. In the present study, a simple and efficient system was established to induce a number of embryogenic calli and regenerate plantlets from hypocotyl explants.

Anther Culture Derived Homozygous Lines in Hordeum bulbosum

AbstractThe production of homozygous doubled haploids via anther culture was investigated in the self‐incompatible diploid species Hordeum bulbosum. Anthers from three accessions (GBC77, GBC752 and GBC753) were cultured on FHG media using IAA or three levels (1, 50 and 100 mg/l) of the auxin phenylacetic acid (PAA). Four green plants and 63 albino plants were obtained from a total of 1620 plated anthers (540/accession). The best mean anther response, number of embryogenic calli and regenerated plants were obtained with 50 mg/1 PAA. Three of the four green plants survived to maturity and, based on root‐tip squashes stained with feulgen, all had 14 chromosomes like the anther donor parent. These anther culture‐derived plants contained only some of the parental DNA bands, as observed by PCR analysis, indicating that they are of gametic origin rather than arising from somatic parental tissue. This is the first report of homozygous lines produced from this self‐incompatible species.

Somatic embryogenesis and plant regeneration in Triticum aestivum x Leymus angustus F1 hybrids and the parental lines

Somatic embryos and plants were produced from cultured inflorescence and leaf segments of Triticum aestivum X Leymus anaustus F1 hybrids and the parental lines. Inflorescences showed a better capacity for somatic embryogenesis and plant regeneration than leaves. Leymus anaustus produced the highest number of embryogenic calli, while the hybrids were intermediate between this species and Triticum aestivum. Presence of 2,4-D was shown to be essential for induction and maintenance of somatic embryogenesis. Addition of five amino acids (glutamine, proline, asparagine, aspartic acid and glutamic acid) did not have any marked effect when they were used in the callus induction medium. The regenerated plants had the same morphology as the original plants. No cytological modification was observed in the examined plants.

Control of Embryogenesis and Organogenesis in Immature Wheat Embryo Callus Using Increased Medium Osmolarity and Abscisic Acid

The effects of various sugars, sugar alcohols and PEG, on the growth, organogenesis and embryogenesis of calli initiated from immature embryos of wheat ( Triticum aeetivum L.) were investigated. Typically, media with higher osmolarities slowed callus growth. The number of shoots per callus and the number of regenerating calli depended on the osmotic potential, carbon source and osmoticum in the medium. The onset of shoot regeneration and the extent of shooting were both increased by adding 3 % sucrose to the basal medium. The number of embryogenic calli and the size of embyogenic sectors per callus were increased by the addition of 3 % sucrose, 3 % mannitol or 5 % PEG to the basal medium. Low concentrations of ABA (0.1 and 1.0mg/l) also increased embryogenesis. The reported effects of osmotic potential, carbon source and ABA on in vitro behaviour will be of value in improving the frequency and uniformity of callus regeneration in wheat.