• Animal cells and systems
• /
• 제4권2호
• /
• pp.131-140
• /
• 2000

The pattern of variations in cone sex ratio and pollen traits such as pollen number and size was examined for two years in populations of red pines In Korea. We evaluated; (1) the relationship between tree size and cone sex ratio, (2) the relationship between year and cone sex ratio, and (3) the relationship between cone sex ratio and pollen traits. Larger trees in height and circumference at breast height produced more male as well as female cones. However, cone sex ratio was independent of these plant sizes. Across the two populations, both female cone numbers per tree and male cone numbers per new shoot increased 2.2 and 1.2 times, respectively, in 1999 compared to 1998, while the yearly pattern of male cone-bearing shoots per tree differed significantly between populations. Thus, cone sex ratio varied significantly between years in one of the two populations. Pollen traits such as the number of pollen grains and diameter did not vary significantly among populations. Pollen diameter and grain numbers per male cone were significantly negatively correlated with the cone sex ratio in two populations and one population, respectively. Trees which stopped female cone production in the first year and those which produced female cones in both years differed in the cone sex ratio and pollen size in the second year. The long duration of one reproductive episode and the potential of masting in red pines emphasize the need to conduct long-term studies on the dynamics of cone production, cone sex ratio, and simultaneous changes in pollen traits in red pines.

• 한국작물학회지
• /
• 제43권4호
• /
• pp.250-253
• /
• 1998

Somaclonal variation was observed in the field on doubled haploid plants derived from single pollen of a rice cultivar "Hwaseongbyeo". The variations of seven quantitative traits including plant height and one qualitative trait (pubescence) in 436 lines ($R_2$ generation) were analyzed. The number of lines which fell beyond the boundaries of the 95% confidence intervals of the check variety, Hwaseongbyeo was checked for each quantitative trait, and of those fertility showed the highest variation frequency (85.6%), followed by plant height (77.5%), flag leaf length (66.5%), grains per panicle (42.2%), days to heading (34.5%), panicle length (30.7%) and panicles per hill (22.7%). And the variations of quantitative traits except days to flowering appeared to move in the negative direction compared to "Hwaseongbyeo". Variability within lines was also observed for quantitative and qualitative traits. Twenty-nine $R_2$ lines (7%) segregated for pubescence and 130 $R_2$ lines (30%) showed variation with regard to fertility. This suggests that mutations usually occur before diploidization. Twenty-nine $R_2$ lines representing a wide spectrum of variation were chosen for RAPD analysis. The number of lines showing DNA polymorphism compared to Hwaseongbyeo ranged 0 from to 10 according to the primer used and this seems to indicate that specific loci have highly mutable genomic site.utable genomic site.

• 식물분류학회지
• /
• 제49권2호
• /
• pp.101-106
• /
• 2019

A pollen morphological study was conducted using light and scanning electron microscopy involving six species belonging to the subtribe Neoguillauminiinae. Pollen samples from the six species are tricolporate, and the colpi are surrounded by broad margo, with the widest width in the equator, narrower toward the pole, and rounded at the end. Based on the pollen morphology, pollen of the species in the subtribe Neoguillauminiinae were divided into four types: the Neoguillauminia type (T1), the C. collinus type (T2), the C. casuarinoides type (T3) and the C. paucifolius type (T4). The generic divergence between Neoguillauminia and Calycopeplus was supported by the pollen characters of the size, amb and lumina shape. In particular, the traits of rounded shape in the outline of the polar view and circular lumina, which appear only in the pollen grains of N. cleopatra, support the recognition of Neoguillauminia as a monotypic genus. Calycopeplus oligandrus and C. paucifolius had the same reticulate pattern of pollen grains, supporting Forster's hypothesis that these two species are closely related. On the other hand, the close relationship between the morphologically similar C. collinus and C. casuarinoides was not supported by the pollen characters. Within the subtribe there are two equally parsimonious hypotheses regarding the evolution of exine characters. The first consists of two changes of microreticulate through parallel evolution from the primitive reticulate exine, and the second is that the microreticulate pattern is differentiated from the reticulate state and then reversed to reticulate pollen grains.

• Current Research on Agriculture and Life Sciences
• /
• 제31권2호
• /
• pp.75-82
• /
• 2013

Haploids are plants with a gametophytic number of chromosomes in their sporophytes. Androgenesis occurs from asymmetric division of pollen grains into generative cells and vegetative cells, followed by re-entry of the vegetative cell during S-phase, which causes microspores progress into G2/M transition in culture. One of the most interesting features of haploids is the possibility to produce doubled haploid (DH) individuals. Doubled haploidy is extremely useful to plant breeders because it enables shortened breeding periods and efficiency in selection of useful recessive agronomic traits. Doubled-haploid technology is not only applicable to breeding, but also to transformation programs of desired genes. In addition to practical breeding programs, DH lines provide useful materials of fundamental genetics including exploitation of QTLs and genes conferred with various agronomic traits by establishing DH populations. This paper provides historical overviews on androgenesis and describes several mechanisms associated with pollen embryogenesis, including mode of actions in pollen embryogenesis, mechanisms of chromosome doubling and factors affecting androgenesis. We also discuss recent progress in application of haploids to breeding, genes associated with in vitro response and drawbacks to anther culture for application of doubled haploids in crop breeding.

• Journal of Plant Biotechnology
• /
• 제34권1호
• /
• pp.47-53
• /
• 2007

To assess the risk of genetically modified (GM) rice on the agricultural ecosystem, agronomic characteristics, pollen longevity and outcrossing rate between GM (Iksan 483 and Milyang 204) and non-GM (their wild types and female parents) varieties were investigated using the bar gene as a tracer marker in paddy field. The agronomic characteristics of two GM rice were similar to their female-parents (non-GM rice) except heading date and 1,000 grain weight of Iksan 483, and they did not show a difference by the introgression of the bar gene as the genetic traits of rice varieties. Pollen viability was more than 90% just after shedding, and it was rapidly decreased below 50% at 5 minutes after shedding both GM and non-GM varieties. The Pollen longevity was lost after 30 minutes of anthesis. When the distance of gene flow from GM to non-GM rice detected to 6 m from the edge of GM rice plant, the maximum distance of pollen dispersal was 4.5m and 3.9m in Iksan 483 and Milyang 204, respectively, and that was increased in order of west, south, east, and north to the dominant wind direction, west-south. Mean outcrossing rate was very low as 0.003 and 0.001% within 1.5 m from the edge of Iksan 483 and Milyang 204, and the GM hybrids by the pollen dispersal did not detected over 4.5 m from the edge of GM rice plant. The results may help to establish the strategy which reduce the risk of pollen-mediated gene flow between GM and non-GM rice.

• 원예과학기술지
• /
• 제33권3호
• /
• pp.390-395
• /
• 2015

The synthesis of chimeras is a breeding approach for horticultural crops. In our breeding program, a new diploid citrus chimera, named 'Hongrou Taoye' (Citrus sinensis [L.] Osbeck + Citrus unshiu Marc.), was found arising at the junction where a 'Taoye' sweet orange (C. sinensis) scion was grafted onto Satsuma mandarin (C. unshiu). As an artificial chimera, its fruit traits derived from the L1 cell layer, with juice color and carotenoid complement, in which ${\beta}$-cryptoxanthin accumulated predominantly, similar to those of Satsuma mandarin. By contrast, traits originating from the L2/L3 cell layer, including pollen, seed, and rind aroma characteristics, were the same as those of 'Taoye' sweet orange (the scion). SSR and cpSSR analyses showed that both nuclear and chloroplast genomes of the chimera were a combination of both donor parents. 'Hongrou Taoye' thus combined the valuable traits of both donor plants, and therefore has good potential in citrus fresh market.

• 한국해양학회지:바다
• /
• 제25권4호
• /
• pp.160-172
• /
• 2020

2014년 춘계에 독도 주변해역에서 전례없이 높은 개체수를 나타낸 야광충의 섭식특성을 이해하고자 야광충 식포 내 먹이생물의 조성과 출현량을 분석하였다. 출현 야광충 개체수는 4,328~17,791 inds.m^-3이었고, 야광충 식포 내 먹이생물 출현율은 평균 32%(24~50%)이었다. 관찰된 먹이생물의 조성은 분변립, 원생생물, 꽃가루, 규조류, 와편모조류, 요각류, 어란, 그리고 치자어로서 매우 다양하였고, 분변립의 출현율이 가장 높았다(43%). 원생생물(19%)과 꽃가루가 18%를 차지한 반면, 규조류와 와편모조류가 각각 7%와 4%를 나타냈다. 식포 내의 출현율을 근거로 분변립, 원생생물과 꽃가루가 어란, 규조류, 와편모조류 그리고 치자어에 비해 더 선호된 것으로 여겨졌다. 본 연구결과는 연구기간에 독도 주변해역에서 출현한 높은 개체수의 야광충이 기존에 알려진 먹이생물 규조류보다 다른 먹이생물과 관련이 높음을 의미하였다.

• The Korean Journal of Ecology
• /
• 제22권6호
• /
• pp.349-354
• /
• 1999

The spatial distributions of allelic frequencies and ecological traits by randomization were studied in the natural population of two species (Pinus rigida and Pyrola japonica). Both species showed significant positive spatial autocorrelation as measured by Moran's I. In P. rigida, the genetic similarity was shown in individuals within up to a scale of 18 m distance and this is partly due to combination of pollen and seed dispersal by wind or men. In P. japonica, significant spatial autocorrelation was consisted of a scale of 8 m intervals. These population structure in the distribution of allelic frequencies is related to mating systems such as outcrossing and vegetative spread. The results also indicate that positive species associations between P. rigida and P. japonica can occur when both species select the same habitat or require the same environmental conditions.

• Weed & Turfgrass Science
• /
• 제5권4호
• /
• pp.196-202
• /
• 2016

국내에는 야생콩이 전국적으로 분포하고 있기 때문에 LM콩으로부터의 야생콩으로 유전자 이동으로 인한 교잡후대종에 관한 연구는 국내 콩 다양성 보전과 LMO 안전관리를 위해 매우 중요하다. 따라서 본 연구는 LM콩과 일년생 야생콩인 돌콩의 교잡후대종 종자의 형태적 및 발아 휴면특성을 평가하여 교잡후대종의 잡초화 가능성을 예측하기 위한 기초자료를 제시하고자 수행되었다. 교잡 1세대의 경우 형태적으로 돌콩과 매우 유사하며, 발아휴면특성 또한 모본인 돌콩과 유사하여 휴면성이 매우 클 것으로 예측된다. 교잡 2세대 종자는 형태적 특성과 발아휴면특성이 부모종의 중간적인 특성을 지니며 모본인 돌콩에 보다 근접한 것으로 확인되었다. 특히 F2의 휴면율은 65.5%에 달할 정도로 매우 높아 잡초화 가능성을 시사한다. 국내 농업환경에서 교잡후대종이 잡초화 되려면 11월 이후에 탈립된 종자가 토양 중에서 월동하여 종자 활력을 유지하고, 휴면이 타파된 후 발아하여 자연 생태계에서 다른 재배종 및 야생종들과 경합하여 생존 및 세대진전을 할 수 있어야 한다. 따라서 LM콩 및 야생콩 간 교잡후대종의 명확한 잡초화 가능성은 종자의 월동성, 생육특성 및 종자생산성 평가 등을 추가적으로 수행하여 다각적인 측면에서 면밀히 평가되어야 할 것이다.

• 한국육종학회지
• /
• 제41권4호
• /
• pp.451-455
• /
• 2009

참나리(Lilium lancifolium)는 우리나라 자생나리로 생육이 왕성하고 후자리움에 내성이 있으며 주아를 형성하는 등 많은 장점을 가진다. 이를 자방친으로 하여 Asiatic hybrid "Dreamland"의 상향이고 흑갈색의 반점이 없는 형질을 이입시키기 위해 교배를 수행하였다. 참나리와 "Dreamland"의 화분발아율은 각각 30과 60%이었다. 이들 후대의 개화일자별 화분의 평균 발아율은 25-57%로 양친의 중간에 분포하였다. 개화는 정식 후 124일째 가장 많았다. 엽형지수는 5 이상인 식물체가 약 99%로 나타나 자방친인 참나리의 영향이 우세하였다. 화색은 4가지로 분리되었다. Orange와 light orange가 각각 51.5와 44.2%로 대부분을 차지하여 자방친의 영향이 우세하였다. 그리고 양친의 중간색인 orange yellow와 light yellow orange는 각각 3.1과 1.2%로 분리되었다. 꽃잎의 반점은 1개체를 제외한 나머지 모든 개체에서 관찰되었다. 개화 방향은 상향, 측향 및 하향 3가지로 분리되었다. 측향 즉, 자방친과 화분친의 중간형이 73% 이었다. 주아는 49.4% 형성되었으며 그 중 최대 25개까지 착생되었다. 평균 주아수는 5개이었다.