The purpose of the study is to assess morphological and chromosomal comparison of Mini type Phalanopsis ‘KS Little Gem’ and four domestic market available cultivars (‘Queen Beer’, ‘Tony Pink’, ‘Vaviche’ and ‘Rorens’). ‘KS Little Gem’ had the highest number of leaves (14.9), while the other four types had fewer than ten. The longest leaf length was 21.5㎝ for ‘Tony Pink’, followed by 16.2㎝, 18.0㎝ and 17.5㎝ for ‘Queen Beer’, ‘Rorens’ and ‘Vaviche’ respectively. The length and width of the petals of ‘KS Little Gem’ were 29.5㎜ and 25.6㎜ respectively indicating a round shape flower compared to other cultivars. When the flower lifespan of ‘KS Little Gem’ was compared to four cultivars of the domestic market, it was found that it had a 123-day shelf life, which was twice longer than that of the four cultivars. According to chromosome analysis ‘KS Little Gem’, ‘Rorens’, ‘Tony Pink,' and ‘Vaviche’ were tetraploid (2n = 4x = 76) while ‘Queen Beer’ was diploid (2n = 2x = 38). The estimated DNA content of ‘KS Little Gem’, ‘Rorens’, ‘Tony Pink’ and ‘Vaviche’ had 4918.4, 4794.2, 4705.2 and 4964.3 Mbp respectively, which were roughly double than that of P. cornu-cervi (control, 2n = 2x = 38). However, ‘Queen Beer’, had an estimated DNA content of 2802.2Mbp, similar to that of P. cornu-cervi. The morphological features, genome size and chromosomal data reported in these studies can be used by breeders to create more efficient Phalaenopsis breeding programs.

본 연구에서는 한국 연안에 서식하는 대표적인 15종 패 류의 핵DNA 함량을 조사하였다. 복족류에서 DNA 함량 (pg DNA nucleus-1)은 3.3±0.08 (Haliotis discus hannai)과 2.4±0.18 (Batillus cornutus)이었다. 이매패류에서 DNA 함 량 (pg DNA nucleus-1)은 2.0±0.15 (Scapharca broughtonii), 3.0±0.12 (Mytilus galloprovincialis), 2.9±0.05 (Meretrix lusoria), 2.2±0.03 (M. lamarkii), 2.6±0.05 (Fulvia mutica), 1.8±0.18 (Tegillarca granosa), 3.3±0.01 (Solen corneus), 2.2±0.04 (Barnea manilensis), 2.5±0.32 (Crassostrea gigas), 3.9±0.24 (Atrina pectinate), 3.5±0.15 (Patinopecten yessoensis), 1.9±0.16 (Amygdala philippinarum) 및 2.3±0.14 (Pseudocardium sachalinensis)이었다. 본 연구 결과는 본 연구에 사용된 패류의 genomic 진화과정을 더욱 잘 이해하는 새로운 정보를 제공한다.

The level at which analyses of DNA content might contribute more significantly to the genetic mechanisms of evolution lies in the events of speciation. The object of this study was to investigate the DNA content of abalone (Haliotis discus hannai) and determine the optimal tissue samples for measuring the DNA content of abalone by flowcytometry without fixation. The DNA content (pg/nucleus) of gill tissue (2.5±0.08), which was contaminated with protozoa, was significantly lower than that of muscle tissue (3.2±0.02), mantle tissue (3.2±0.02) (p<0.05), and a standard reference standard, while the DNA contents of muscle tissue and mantle tissue were higher than that of the standard reference. Considering the results of this study, DNA content analysis with flowcytometry is an acute and rapid method by which muscle tissue and mantle tissue are the most appropriate sample for measuring the DNA content of abalone without fixation.

Polyploidy analysis being one of the important mechanisms to study the genetic resources and plant diversity which plays significant role in crop evolution, breeding programs, and crop improvement was conducted in this study. The root tips of nine Cymbidium genotypes were used as materials to determine their chromosome number and flow cytometric analysis of chromosomal ploidies. The chromosome number (2n=40) has been observed in all the nine genotypes. Results showed that among nine cymbidium genotypes, six were tetraploid (2n=4x=80), two diploid (2n=2x=40), and one triploid (2n=3x=60). This study provides useful chromosome landmarks and evidence about genome evolution, heteromorphic chromosomes based heterozygosity, basic chromosome number and ploidy level in the genus Cymbidium. These results can be used as theoretical base line for crossbreeding in the genus Cymbidium.

The present study was performed to compare the morpho-physiological characteristics of the tetraploid and diploid varieties of Platycodon grandiflorum and to obtain basic data for cultivating a tetraploid variety with high yield and content of functional substances. The plant height of the tetraploid variety (54.0 cm) was slightly higher than that of the diploid variety. The leaf length and width of the tetraploid variety were 10.2 cm and 7.3 cm, respectively. The results obtained from the present study revealed that the form of the leaf changed from lanceolate to ovate, and the chlorophyll content in the tetraploid variety (16.7) was slightly higher than that in the diploid variety. The photosynthetic rate significantly increased (24%) to 13.4 μmol CO2·m -2 ·s -1 in the tetraploid variety from that of the diploid variety. The pollen viability of the tetraploid variety was decreased by approximately 33% with respect to that of the diploid variety, but this did not have a significant adverse effect on seed production. The fresh weight of tetraploid P. grandiflorum was 49.4 g, which was approximately 44% higher than that of the diploid variety.

Ionizing radiation directly and indirectly affects gene expression within the plant genome. To access the physiological response of rice to different types of ionizing radiation, rice seeds were exposed to gamma-ray and ion beam radiation. Exposure to ionizing radiation dramatically decreased the shoot length compared with non-irradiated plants. Fluorescence-activated-cell-sorting (FACs) was used to measure DNA contents. There were significant correlations of dose-dependent between irradiated plant and non-irradiated plant. The radicals induced by the ionizing radiation in the plant could be observed by electron spin resonance (ESR). It was confirmed that the number of free radicals in cell was greatly increased all irradiated plants than non-irradiated plant. A significant positive correlation was shown between ionizing radiation dose and signal intensity. In order to determine the Genetic diversity, AFLP analysis was conducted with the irradiated plant and non-irradiated plant. Based on band patterns, the cluster analysis was conducted to evaluate the genetic variation by using the UPGMA (Unweighted Pair Grouping Method of Averages). Genetic diversity of irradiated plants by low dose ion beam was the closest non-irradiated plant and irradiated by high dose gamma-ray was the furthest from non-irradiated. We describe the detailed methods of ionizing irradiation and discuss its applications in genetic research as well as plant breeding.

'망종화'에서 콜히친 처리에 의한 효율적인 4배체 식물을 유도하고자 적정 식물체 부위, 적정농도 및 침지시간을 검토하였다. 종자의 발아율은 콜히친의 농도가 높을수록 또한 침지시간이 길수록 저하되었다. 대조구를 제외한 16개의 처리구에서 총 453개체가 발아된 반면 4배체는 유도되지 않았다. 기내 배양 중인 줄기 절편체의 식물체 재생율은 콜히친 처리농도 0.01%에서 최고를 나타내다가 0.1% 농도 이상으로 높아질수록 낮았다. 적정식물체 부위는 줄기 절편체로 나타났다. 4배체 식물은 콜히친을 0.05% 이상으로 6시간 침지처리 하였을 때 얻을 수 있었고, 특히 0.05%, 12시간 침지처리에서 식물체의 재생수 대비 약 42%의 높은 획득율을 보였다. Flowcytometry에 의해 DNA함량의 배가여부를 확인한 결과, G1 phase의 DNA 함량 peak가 2배체에서 94.5, 4배체는 192.5로, DNA가 배가됨을 확인할 수 있었다. 또한 공변세포 당 엽록체 수는 2배체가 약 10개인 것에 비해 4배체는 17~19개로 2배체보다 약 1.7~1.9배 정도 많았다.

Allium 속 근연종인 파와 양파간 종간교잡을 이용하여 양파로부터 새로운 형질을 도입하는 과정에서 유래되는 종간교잡 F1과 여교잡 세대들의 게놈크기의 변화를 flow cytometry를 이용하여 측정한 결과 다음과 같은 결과를 얻었다. 1. 양파와 파의 종간교잡 F1의 식물학적 특성은 양친의 중간형을 보였으나 여교잡이 진전됨에 따라 반복친인 파의 표현형이 우세하였다. flow cytometry를 이용하여 2C nuclear DNA content을 측정