Plant regeneration from stems and leaves was carried out for the growth of biomass, hybrid poplar(Populus alba x P. glandulosa)clone, which has various uses for plant purification. Callus was well induced when stem and leaf tissues were cultured in 1.0 mg/L 2,4-D containing MS medium. Shoot regeneration was best induced by zeatin among growth regulators, and Plant regeneration was more regenerated in leaf-derived callus than in stem-derived callus. The growth of regenerated shoots at high and low concentrations of zeatin was similar to that of the control at low concentrations. As the concentration of growth regulators increased, the growth of regenerated shoots showed a big difference among individuals. Hybrid poplar showed color variation of plant stem in medium containing high concentration of growth regulator. Regenerated individuals were in vitro rooted in MS medium containing 0.5 mg/L IBA after 2 weeks of culture. and transferred to the greenhouse for acclimatization. The study is believed to be widely used for the induction of in vitro variants through organogenesis.

MYC (v-myelocytomatosis viral oncogene homologue) is a regulator gene that encodes for a nuclear phosphoprotein. Porcine MYC gene was mapped on chromosome SSC 4p13 and is associated with a variety of functions such as cell proliferation and cell growth. MYC expression is coupled to a multitude of physiological processes and is regulated by hormones, growth factors, cytokines, lymphokines, nutritional status, development and differentiation. MYC is also involved in myogenesis, muscle hyperplasia and adipogenesis. In this study, we investigated SNPs in MYC gene and their association with economic traits in Duroc, Landrace and Yorkshire populations. We detected a single point mutation in exon 3 of porcine MYC gene as a change of T to C at 906 base (amino acid position 302, nonsynomous mutation of alanine) in MYC-N domain. MYC mutation (T906C) was significantly associated with age at 90 kg in these breeds, signifying that this mutation can serve as a selection marker for growth traits in pigs.

The objective of this study was to determine the potential hazardous effects of sorting process by flowcytometry on the quality of boar spermatozoa by flowcytometer. Freshly collected boar semen was diluted and divided into two groups; control none sorted and sorted. Sperms in sorted group were processed with flowcytometer for cell sorting with 100 uM nozzle under the 20 psi pressure. Measurements on each parameter were made at two time points, 0hr (right after sorting) and 24 hr post sorting. Although there was a tendency of lower viability in sorted group than none sorted control group, the percentage of live cells in control(75.83+-6.92 & 59.53+-10.34) was not significantly different from sorted (59.7+-7.34 & 43.97+-3.76) at both 0 and 24 hr post sorting. However, sorted sperm showed significantly lower mitochondrial function compared to the control at both 0 h (79.37+-3.22 vs. 63.50+-10.05) and 24hr(67.27+-3.22 vs. 46.97+-5.37) time points (p<0.007). Sperm DNA fragmentation rate was significantly lower in control (22.0+-7.04) than that of sorted (32.27+-7.49) at 24 hr time point (p<0.0002). Taken together, these data suggested thatsorting process by flowcytometer may have influenced sperm motility rather than viability. Also high speed sperm sorting by flowcytometer has significant effects on DNA fragmentation on elapsed time after sorting.