거베라 ‘Sunny Lemon'의 양액재배시 양액함량 조절이 생육 및 절화특성을 알아보고자 미치는 영향을 알아보고자 입상암면과 피트모스와 펄라이트 혼합배지(2:1, v/v)에 거베라 'Sunny Lemon' 유묘를 정식한 후 약 1달 동안 온실에서 순화시킨 후 배지내 양액의 함량이 각각 80-85%, 70-75%, 60-65%로 유지되도록 TDR센서(UT-TM, Ultra-Tech., Korea)를 부착하여 지속적으로 공급되도록 하였다. 양액은 거베라 sonneveld 양액을 1/2농도로 조성하여 초장이 평균 20±1 cm인 6월 24일 개시하였다. 영양생장에서 생식생장 전환 시점인 2개월 후 거베라의 생육을 조사한 결과, 배지종류에 따라서는 입상암면이 혼합배지보다 초장, 엽폭 및 엽수가 약 10% 더 증가되었지만 통계적으로 유의성은 없었다. 급액함량에 따라서는 2가지 배지 모두 배지내 양액 공급함량이 80-85% 때 가장 생육이 좋았으며, 생육초기보다 엽수는 약 60%이상, 엽폭과 초장은 약 40%정도 증가되었다. 첫 개화시점, 절화 품질 및 수량은 배지내 양액 함량이 높을수록 양호하였으며, 개화시점도 배지내 양액함량이 60-65%일때 보다 약 7-10일 빠른 것으로 조사되었다. 총 급액량은 입상암면보다 혼합배지내의 양액함량을 80-85%로 유지시킬 때 더 많이 소모되었으나, 배지의 EC, pH 변화는 입상암면에서 큰 것으로 보아 1회 정식 후 3년이상 재배되는 거베라 'Sunny Lemon'의 생육, 절화 품질 및 수량은 혼합배지에서 급액함량을 80-85%로 유지하여 재배할 때 가장 우수한 것을 알 수 있었다.

Lettuce was a leaf vegetable with short growing term and cold-tolerant plant. We grew it the whole year. The price of lettuce is the most expensive from July to September. But damages by lots of insect pests appear to greenhouse grown lettuce in summer season. In this study, we observed biological controls of western flower thrips(Franklinella occidentalisi) by the predator mites, Amblyseius swirskii and Neoseiulus cucumeris in lettuce greenhouse from July 7 to September 10. Hypoaspis aculerfer larvae and adults were released 30 individuals per m2 at the first one time as lettuce was planted on the greenhouse. We checked the density of F. occidentalis every 10 days on the 30 lettuce leaves. When the population of F. occidentalis reached 1~5 individuals per a leaf, A. swirskii larvae and adults were released 35 individuals per m2 at 1~3 times and Neoseiulus cucumeris larvae and adults also were released 150 individuals per m2 at 2~3 times in each lettuce greenhouse. During the high temperature season, Amblyseius swirskii was more effective biological controls of F. occidentalis than Neoseiulus cucumeris.

Blossom midge, Contarinia maculipennis Felt (Diptera: Cecidomyiidae) is originated in Southeast Asia and has been present in Japan, USA and Hawaii. Recently, C. maculipennis was intercepted in Japan, USA and Netherlands with orchid flowers imported from Southeast Asian countries. This pest is designated as quarantine pest in Korea because of its potential damages to vegetables and ornamental plants in case when this pest introduced in Korea. C. maculipennis has known to feed inside unopened flower buds, causing deformed, discolored buds and blossoms. And, in severe infestations, cause premature bud or blossom drop. In Korea, similar damage symptoms have been reported in western orchids which mighty be caused by C. maculipennis from Mid-2000s, especially on D. phalaenopsis. An official recognition to C. maculipennis was given in 2007. And, the occurrences of C. maculipennis and its damages were investigated mainly on D. phalaenopsis in 2008~2009. We emphasize caution about recognizing the possibilities that C. maculipennis could infest flower buds of an orchids and carry out management strategies for this pest in the future.

This study was conducted to develop economic injury level (EIL) and economic threshold (ET) of onion thrips, Thrips tabaci on welsh onion (Allium fistulosum L. var). The changes of welsh onion biomass and T. tabacci density were investigated after introductions of T. tabacci at different densities and days: By the results of the experiment in the early welsh onion cultivation periods (30d after transplanting), the biomass of welsh onion significantly decreased with increasing the initial inoculated density of T. tabacci. The relationship between cumulative insect days (CID) and yield loss (%) of welsh onion was well described by a nonlinear logistic equation. Using the estimated equation, EIL and ET of T. tabacci on welsh onion were estimated at 24 and 20 CID per plant, respectively. By the results of the experiment in the late cultivation periods of welsh onion (about 120d after transplanting), the welsh onion biomass was also significantly different inoculation thrips densities to welsh onion. The EIL and ET were calculated as 35 and 28 thrips per welsh onion plant. Until a more elaborate EIL-model is developed, the present result may be useful for T. tabacci management during the cultivations of welsh onion.

This study was conducted to evaluate the effects of temperature and nematicides on endospore attachment characteristics of 2 Korean isolates of nematodeparasitic bacteria, Pasteuria penetrans. P. penetrans CJ-1 and 98-35 isolates and 3 species of root-knot nematodes in U. of Florida were used ; Meloidogyne incognita (MI), M. arenaria (MA), and M. javanica (MJ). Three nematicide levels of 2, 4, and 6 ppm were compared by treating Vydate and Nemacur in the endospore containing soils. The endospores were attached to the root-knot nematode juveniles by centrifugal method. Reproduction of the isolates was checked by observing root-knot nematode females harvested from inoculated tomato roots. 1. Among the two Korean isolates, 98-35 showed attachments to MI, MA, and MJ juveniles, but it could not reproduce in any species. CJ-1 reproduced on all the 3 tested root-knot nematode species. 2. Endospores pretreated in -14°C showed higher attachment rate than those pretreated in 4, 24, and 40℃. 3. Nemacur treatments significantly suppressed the attachment of the endospores to the juveniles, while Vydate treatment effects were negligible.

A storage mite (cheese mite), Tyrophagus putrescentiae, is known as the pest in storing grains and common health pest species in the dust around home. The mite directly affect our well-being as parasites, vectors of disease, and producers of allergens. But recently we found damages in horticultural crops especially in greenhouses. It is very difficult to diagnose the damage by the mite because of the tiny size of the mite. And the symptom is not clear at the beginning stage. In this study, observations were done on the mite and the crop damage symptoms in several horticultural crops under dissecting microscope and scanning electron microscope (SEM). The mite body size was 0.3~0.5㎜ and they had long hairs all around their body when observed under SEM. The characteristic damage symptoms in some horticultural crops are as follows. In phalaenopsis, the flower buds became yellow and the lower side of the leaves had white spots. The surface of young cucumber fruits became shiny and soft at the early damage stage. In the crops, the damaged surfaces became corky as the plants grew up. In peach tree, whole the trees lost vigor and flower drops were observed when the mite density was very high in greenhouse cultivation.

The Asteraceae/Compositae family is one of the biggest families in flowering plants and has more than 23000 species including the economically important lettuce, sunflower, and chicory as well as the agronomic weeds. With its significance and the progress in sequencing technology, its species have been subjected to the genome sequencing project worldwide. Although chrysanthemum is an important plant in the floricultural industry, however, it has been less studied at the level of genomics, compared with other species in the Asteraceae. There were only several reports on comparative analysis of transcriptome for chrysanthemum. Actually, the genome of Chrysanthemum species is known to be gigantic and complex with diverse status ranging from diploid to decaploid. Since the cultivated and commercial chrysanthemum exhibits hexaploid genome, we decided to select the diploid species with smaller genome as a material for reference genome sequencing. Thus, we launched a genome sequencing project with C. boreale which was previously reported to be diploid by cytogenetic analysis. We constructed sequencing libraries with insert size 300bp and 500bp and sequenced them from the paired end in 100bp read length with Illumina’s HiSeq platform. After quality checking, we preprocessed raw reads by removing duplicated reads and trimming reads with low quality value. Kmer frequency analysis with the cleaned reads showed that the genome is heterozygous, highly repetitive and gigantic, ranging from 2.9Gb to 5.8Gb. The cleaned reads were further subjected to error correction and primary assembly with SOAPdenovo2. Here, we’ll report the result of Kmer frequency analysis and genome assembly.

Chrysanthemum white rust, caused by Puccinia horiana, is one of the most destructive fungal diseases in chrysanthemum cultivation worldwide. For increasing efficiency of resistant breeding, molecular markers linked to chrysanthemum white rust resistance gene were developed in pseudo F1 cross population between ‘Puma White’ as susceptible and ‘Dancer’ as resistant using bulked segregant analysis (BSA). Of 280 RAPD primers (Operon 10 mer), 18 primers found to be polymorphic. After screening of these primers in 20 individual lines, only OPI-13520 was selected as closely linked marker to white rust disease resistance. Based on correspondence between phenotypic resistant level and marker in 187 segregation population, the genetic distance between white rust resistance gene and OPI-13520 marker assumed to be 3.8 cM. For OPI-13520 marker conversion into sequence characterized amplified region (SCAR) marker, the amplified fragment of OPI-13520 was purified, cloned and sequenced. Based on the DNA sequence of OPI-13520, SCAR maker was generated and verified in 20 individual lines used in BSA-RAPD.The results showed SCAR marker could be used to identify white rust resistance in chrysanthemum.

For developing molecular markers linked to white rust resistance in chrysanthemum, RAPD and AFLP were carried out in ‘Puma White’ x ‘Dancer’ mapping population through Bulked Segregant Analysis (BSA) methods. 10 resistant and 10 susceptible individuals were selected and bulked. And then, these bulks were screened using 280 RAPD primers (10 mer) with two parents. As a result of BSA-RAPD, 25 Dancer/R-bulk specific bands in 21 primers and 22 Puma White/S-bulk specific bands in 18 primers were selected. These resistant or susceptible specific bands were screened in 10 resistant and 10 susceptible individuals. Except OPI-13520, all bands were confirmed as false positive. OPI-13520 band presumed as closely linked marker to white rust disease resistance was tested in whole population. Among 187 progenies, just six off-springs did not correspond with phenotypic data. Based on expected phenotypic segregation ratios in the pseudo F1 progenies, it was assumed that a duplex type of white rust resistance in ‘Dancer’ (RRrrrr) were in combination with a duplex type of OPI-13520 marker. As a result of x2-test of independence between resistance gene and OPI-13520 marker, x2 score is 76.08 and probability is 2.13x10-16. And resistance gene and OPI-13520 marker were assumed to be linked in coupling phase. The value of recombination fraction obtained by successive trials and second derivative of log likelihood was 0.03832±0.0271.