RESEARCH ARTICLE 억새원예품종의출수특성과화서가시성평가 김기동 1,2 주영규 2* 1 한국골프대학교, 2 연세대학교생명과학기술학과대학원 Assessment of Heading Perfor

Transcription

1 RESEARCH ARTICLE 김기동 1,2 주영규 2* 1 한국골프대학교, 2 연세대학교생명과학기술학과대학원 Assessment of Heading Performance and Inflorescence Visibility in Miscanthus sinensis Cultivars Ki-Dong Kim 1,2 and Young-Kyoo Joo 2* 1 Department of Golf Course Management, Korea Golf University, Hoengsoeng 25247, Korea 2 Department of Biological Science and Technology, Graduate School of Yonsei University, Wonju 26493, Korea *Corresponding author: ykjoo@yonsei.ac.kr Received: August 29, 2018 Revised: November 29, 2018 Accepted:December 7, 2018 OPEN ACCESS HORTICULTURAL SCIENCE and TECHNOLOGY 37(2): , 2019 URL: pissn : eissn : This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Copyrightc2019 Korean Society for Horticultural Science. Abstract Miscanthus sinensis (Poaceae) cultivars have great values as ornamental grasses and adapt well to various environmental conditions. To assess the inflorescence visibility of seven popular Miscanthus cultivars ( Gold Breeze, Strictus, Morning Light, Variegatus, Gracillimus, Kleine Fontäne, and Common ), the heading performance and morphological characteristics were analyzed. The test cultivars were transplanted and cultivated on research plots in 2013 and data were collected from July 2017 to February Among the six cultivars, except Gold Breeze, which had not bloomed during the research period, Kleine Fontäne showed the longest heading period and the highest peduncle density. Heading patterns were classified in the early and the late heading patterns. The early heading pattern cultivars ( Kleine Fontäne, Common, and Strictus ) had a high weekly heading rate (WHR), and reached later heading peak time with low mean heading rate (MHR). However, the late heading pattern cultivars ( Variegatus, Gracillimus, and Morning Light ) had high WHR at the beginning of the heading initiation and reached earlier heading peak time with high MHR. The changes of inflorescence stage were classified into the flowering season (stage 1), the seed maturation (stage 2), and the seed shatter stages (stage 3). The inflorescence colors were expressed with a reddish ( Strictus, Morning Light, Variegatus, Gracillimus, and Common ) and a yellow-greenish ( Kleine Fontäne ) color in stage 1. The color difference value (ΔE*ab) was greater at stage 1 and stage 2; however, ΔE*ab was decreased in stage 3 compared with the reference inflorescence color of Common. The morphological characteristics of inflorescences were significantly different among the cultivars, such as the plant height, stem length, dissociation index, length, width, length/width ratio, raceme density, and spikelet density. On the assessment of inflorescence visibility, the morphological characteristics showed a decisive component in Common, Strictus, Variegatus, and Gracillimus ; on the other hand, the heading characteristics were more influential on visibility in Kleine Fontäne and Morning Light. These results suggest that the inflorescence visibility of Miscanthus cultivars was determined by various factors of the heading and morphological characteristics of inflorescence. 290 Horticultural Science and Technology

2 Additional key words: dissociation index, ornamental grasses, peduncle, Poaceae, weekly heading rate 서언관상용그래스 (ornamental grasses) 는경관가치와지속성이우수한식물로벼과 (Poaceae), 사초과 (Cyperaceae), 골풀과 (Juncaceae), 부들과 (Typhaceae) 및레스티오과 (Restionaceae) 의 5가지분류군에분포되어있다 (Darke, 2007). 양지, 음지, 건조, 습지및수변등다양한생육환경에적응하고, 여러가지토성 (soil texture) 과척박한토양에도적응력이우수하여 (Davidson and Gobin, 1998; Dougherty et al., 2015) 전세계적으로녹지, 건축조경, 가정원예분야에서광범위하게식재되며 (Gao and Liu, 2005; Wu et al., 2006; Thetford et al., 2009) 다양한원예품종이개발되고있다. 최근기후변화의영향으로내서성과내건성이우수한종이주목받고있으며, 특히관리요구도가낮아국내에서도하천변, 가로변, 광장및공원등의저관리지역 (low maintenance area) 에서식재빈도가높아지고있다 (Kim et al., 2013). 그러나긴지하경 (rhizome) 과지상경형태 (stoloniferous) 로생장하거나종자번식력이높은종 (spp.) 은침입성 (invasive potential) 이강하여생태계교란가능성이높아종의선택시생장습성 (growth habit) 과번식특성을고려할필요가있다 (Meyer and Tchida, 1999; Meyer, 2004; Dougherty et al., 2014; Bonin et al., 2017). 현재관상용그래스가가장많이속해있는벼과는세계적으로 여속, 8,000-10,000여종이분포하고있으며 (KFS, 2015) 국립수목원 (Korea National Arboretum, KNA) 국가표준식물목록 (Korean Plant Names Index, KPNI) 에명시된관상용그래스의 5가지분류군중 40.4% 가벼과에속해있어잠재적유전자원이풍부한식물군으로해석될수있다 (KNA, 2018). 우리나라에서는억새속 (Miscanthus), 수크령속 (Pennisetum) 식물이원예및조경용의관상용그래스로주로식재되고있는데억새속식물은 C 4 type의다년생식물 (Greef et al., 1997) 로국내에는물억새 [Miscanthus sacchariflorus (Maxim.) Benth.] 와억새 (Miscanthus sinensis Andersson) 계통들이전국각지에자생하고있다. 물억새는하천변이나물가에자라는키큰풀로긴지하경이있고대군락을이루며줄기의직립성이강한반면, 억새는산이나평지, 초원에자생하는식물로짧은지하경이있고줄기는총생하며포기를이룬다 (Lee, 2003). 이러한억새의생장습성 (growth habit) 은물억새에비하여상대적으로관상용그래스로적합하여현재가장많은원예품종이개발되어있으며초고 (plant height), 초형 (overall form), 질감 (texture) 및잎의무늬 (leaf pattern) 가다양한 20종의재배종이 KPNI(KNA, 2018) 에명시되어있다. 관상용그래스의경관감상은영양생장기에해당하는 1차감상시기와생식생장기에해당하는 2차감상시기까지연속적으로이어지며생육상이전환되면서경관요소가달라진다. 1차감상시기에는초고, 초형, 질감, 잎의무늬및엽색 (leaf color) 을감상할수있다 (Kim et al., 2015). 특히관상용억새의독특한무늬와엽색은 1차감상시기의주요경관요소가되며엽맥과교차하는무늬가있고두가지색을가진 zebra-stripe type(m. sinensis Strictus etc.), 엽맥과평행하는무늬가있고두가지색을가진 stripe type(m. sinensis Variegatus etc.), 무늬가없는단색의 normal type(m. sinensis Gracillimus etc.) 으로구분할수있다. 그리고 2차감상시기에는출수 (heading), 화서 (inflorescence) 및엽색의변화 (discoloration) 가경관요소가되며출수특성 (heading characteristics) 과화서의가시성 (inflorescence visibility) 은 2차감상시기의주요경관요소가된다 (Wilson and Knox, 2006, 2009; Gunnell et al., 2015). 억새의꽃은우리나라에서는 8-10월사이에피며포영 (glume), 호영 (empty glume), 내영 (inner glume) 으로둘러싸여여러개가피고화서는길이 20-30cm로 10-25개의총 (raceme) 이길게배열되어있다 (KFS, 2015). 꽃은크기가작고유지기간이짧지만화서는유지기간이길며밀집된정도와색채가조합된전체적인이미지에따라가시성의핵심적인요소가된다. 관상용그래스의경우종과품종 (cultivar) 에따라서다양한형태와색채의화서가나타나는데초형과화서의시각적분리가명확하고밀도가높으며색채변화가뚜렷할수록화서의가시성이높다. 화서의가시성은 1차감상시기부터이어지는경관의연속성측 Horticultural Science and Technology 291

3 면에서중요한요소이나국내억새속식물의연구는에너지작물교배육종모본선발을위한출수특성연구 (An et al., 2015; Song et al., 2018) 와플라워디자인소재에관한일부연구 (Sohn and Kwon, 2008) 등에서만제한적으로보고되고있어관상용그래스로서에대한연구가부족하다. 본연구에서는국내저관리지역에식재되고있는관상용그래스억새품종 7가지를선정하여총출수기간 (total heading period), 화경밀도 (density of peduncle), 평균출수속도 (mean weekly heading, MWH), 주간출수율 (weekly heading rate, WHR), 출수피크타임 (heading peak time), 출수집중도 (mean heading rate, MHR), 출수패턴 (heading pattern), 화서색채 (inflorescence color) 및화서의형태적특성 (morphological characteristics) 을분석하고 2차감상시기의주요경관요소인출수특성과화서의가시성을평가하였다. 재료및방법공시재료, 시험포장조성및실험기간공시재료는국내에서식재되고있는억새 (M. sinensis) 자생종과원예품종중에서초고와잎의무늬가다양한 7품종을선정하였다 (Table 1). 일반적인특성은미농무성 (U.S Department of Agriculture, USDA) 의 Natural Resources Conservation Service Plant Database(USDA, 2018) 와 Missouri Botanical Garden(MBG) 의 Plant Finder(MBG, 2018), The Encyclopedia of Grasses for the Livable Landscapes(Darke, 2007), 산림청 (Korea Forest Service, KFS) 의한국식물도해도감 (KFS, 2015) 및원색대한식물도감 (Lee, 2003) 를인용하였다. 식물명은국립수목원 (KNA) 의 KPNI에명시된학명과품종명을표기하였고 (KNA, 2018) 일반명은국가와지역에따라다양하게사용되는경향이있어생략하였다. 2012년 6월연세대학교원주캠퍼스연구온실 ( 강원도원주소재 ) 에서모본들을재배하였고월동시킨후 2013년 3월줄기수가 5-7개포함되도록분주하여교내시험포장에정식하였다. 포장면적과식재본수는성숙된크기를고려하여한품종당 16m 2 (2m 8m), 재식간격 1m로 12본씩식재하였으며초기활착을위한관수 (irrigation) 관리를제외하고 2017년까지무관수, 무시비관리로저관리지역에서생장할수있도록재배하였다. 전체실험기간은 2017년 7월부터 2018년 2월까지였고조사항목마다데이터수집기간은달랐다. Table 1. Height, leaf pattern, growth habit and overall form of seven Miscanthus sinensis cultivars in this study Cultivar Height (m) Leaf pattern Growth habit Overall form Gold Breeze Strictus Zebra-stripe z Morning Light Stripe y Variegatus Short rhizomatous w Upright arching v Gracillimus Kleine Fontäne Normal x Common z Horizontal bands of yellow variegation. y Longitudinally striped with a leaf vein of light golden-yellow or white variegation. x Green color without variegation. w Clumps slowly expand in circumference by short rhizomes but typically retain tight clump shape. v Foliage ascends stiffly and vertically, then falls in a fountain of arcs from the top. Gold Breeze and Strictus are more upright than other cultivars. 292 Horticultural Science and Technology

4 총출수기간, 화경밀도및평균출수속도총출수기간, 화경밀도및 MWH 조사는 2017년 7월부터 11월까지 1주일간격 4반복 (4개체) 으로실시하였다. 본실험에서는 Jensen 등의연구 (Jensen et al., 2011, 2013) 와농촌진흥청 (Rural Development Administration, RDA) 농업과학기술연구조사분석기준 억새의생육및특성조사 (RDA, 2012) 에서출현기의정의에따라전체 12본중 5본이상의개체에서화서가지엽을뚫고출현한출수시작시점부터출수종료시점까지의기간을총출수기간으로산정하였다. 화경밀도는 1본당총화경개수로정의하였고총출수기간동안화서가 1cm 이상출현한화경의개수를 1주일간격으로조사하고누적하여산출하였다. MWH는 Association of Official Seed Analysts(AOSA) 의종자분석방법 (AOSA, 1990) 을응용하여총화경수 ( 화경밀도 ) 를조사주수 ( 총출수기간 ) 로나눈값으로정의하였다. 평균출수속도 (mean weekly heading, MWH) = N/T N: total number of peduncles T: total heading period 주간출수율, 출수피크타임, 출수집중도및출수패턴 WHR, 출수피크타임, MHR는 2017년 7월부터 11월까지 4반복으로조사하였으며종합하여출수패턴을분석하였다. WHR은출수시작후 1주간격으로산출한화경개수를총화경수로나누어백분율을산정하였다. 주간출수율 (weekly heading rate, WHR = (ni/n) 100 ni: number of peduncles per week N: total number of peduncles 출수피크타임은조사기간중 WHR이가장높은시기를 1차출수피크타임 (peak I) 으로정의하고소요주수 (week after heading) 와 WHR을명시하였다. 2차 (peak II) 및 3차출수피크타임 (peak III) 은 Wilson과 Knox의연구에서적용한 5단계척도 (Wilson and Knox, 2006) 를응용하여출수후누적출수율 (cumulative heading rate, CHR) 이 50% 이상되는시기를 2차출수피크타임, CHR이 75% 이상되는시기를 3차출수피크타임으로정의하고각각의소요주수와 CHR을명시하였다. 3차출수피크타임이후출현한화경은화서의캐노피 (canopy) 형성에영향이적었기때문에 3차출수피크타임까지의 CHR을소요주수로나누어 MHR을산정하였다. 출수집중도 (mean heading rate, MHR) = Σ[(ni/N) 100] / ti Σ[(ni/N) 100]: cumulative heading rate (CHR) to investigation weeks ni: number of peduncles per week N: total number of peduncles ti: investigation weeks after heading Horticultural Science and Technology 293

5 화서색채화서색채에대한조사는 2017년 7월부터 2018년 2월까지실시하였고화서변화단계를개화기 (stage 1), 종자성숙기 (stage 2), 종자탈립기 (stage 3) 의 3단계로구분하였다. 각단계마다색채변화가 80% 이상진행된시점에서표현되는색을대표색으로설정하고색차계 (CR-300 R colorimeter, Minolta, Japan) 로 L * a * b * (CIE 1976 L * a * b * 색공간 ) 값을측정하였다. 측색과정에서의오차를줄이기위하여차광캡을설치하고구경보다지름이작은 petri dish(ø55mm) 위에화서변화단계별대표색으로판단되는화서부위를일정한길이로절단하여여러개를포개어면 (face) 을형성하였고광노출을피해암실에서 6반복으로측정하여평균값을취하였다. 색차이값 (ΔE*ab) 은억새자생종 (M. sinensis Common ) 의화서색채를기준색 (reference color) 으로정하고 Nickerson Index of Fading의색차식을사용하여화서변화단계별로각품종간 ΔE*ab를구하였다 (Chen et al., 2016). 두색차간최소식별차이 (just-noticeable difference, JND) 값은 ΔE*ab 2.3을적용하여기준색과의차이를구분하였다. ΔE*ab = L L a a b b L L a a b b the difference of color values compared with reference color 화서의형태적특성화서의형태적특성은화서색채실험에서적용한화서변화 3단계중에서 stage 2에해당되는종자성숙기에실시하였고조사시기는품종마다달랐다. 농업과학기술연구조사분석기준 (RDA, 2012) 을참고로하여초고 (plant height), 간장 (stem length), 분리지수 (dissociation index), 화서길이 (length), 화서폭 (width), 장폭비 (length/width ratio), raceme 밀도 (raceme density) 및 spikelet 밀도 (spikelet density) 를조사하였다. 초고는자연상태에서의초형의높이, 간장은지면에서이삭하단부까지의길이, 분리지수는초고와간장의비율, 화서길이는자연상태의직선길이, 화서폭은자연상태에서가장넓은폭, 장폭비는화서길이와폭의비율, raceme 밀도는화서하나에달린 raceme의수, spikelet 밀도는 raceme 3cm를단위길이로하여단위길이당 spikelet의수로정의하였다. 화서가시성평가화서가시성평가는 Smith and Fellowes(2015) 의꽃의개수와크기로가시성을평가한방법을응용하였으며출수특성과화서의형태적특성을종합하여실시하였다. 전체조사항목중에서화서가시성평가를위한출수특성은화경밀도, MWH 및 3차출수피크타임의 CHR, 화서의형태적특성으로는분리지수, 화서길이및 raceme 밀도를선정하였다. 각항목마다본실험에서조사된통계적등급에따라 1점부터 5점까지 0.5점단위로부여하였으며출수특성과화서형태적특성의평균점수를산출하여 (scale1-5; 1 = poor quality, 3 = average quality, 5 = excellent quality) 화서의가시성을평가하였다 (Wilson and Knox, 2006). 기상, 토양환경및재배관리 2017년 7월부터 2018년 2월까지실험기간동안의기상데이터는시험포장에서인접한원주기상청 (Korea Meteorological Administration; KMD) 의관측자료 (KMD, 2018) 를수집하여월평균기온 (monthly mean temperature), 월평균최저기온 (monthly mean minimum temperature) 및월누적강수량 (monthly cumulated precipitation) 을조사하였다 (Fig. 1). 사양토 (sandy loam) 로조성된실험포장토양이화학성분석은공시재료정식시에실시하였으며농업과학기술연구조사분석기준 294 Horticultural Science and Technology

6 Fig. 1. Monthly mean temperature (MmT), monthly mean minimum temperature (MmmT), and monthly cumulated precipitation (MCP) in the research field from July 2017 to February Table 2. Soil test results following the Standard book on research, investigation and analysis of agricultural science and technology (RDA, 2012) before planting in the research plot Soil texture ph (1:5) EC (1:5) (ds m -1 ) OM (%) CEC (cmol kg -1 ) Avail. P 2 O 5 (mg kg -1 ) NO 3 (mg kg -1 ) K + (cmol kg -1 ) Sandy loam 농업환경 (RDA, 2012) 분석방법에준하여토성 (soil texture), ph, 전기전도도 (electronic conductivity), 유기물함량 (organic matter), 양이온치환용량 (cation exchange capacity), 질산태질소 (NO 3 ), 유효인산 (P 2 O 5 ), 칼륨 (K + ) 함량을분석하였다 (Table 2). 재배관리는 2013년정식후초기활착을위한관수를제외하고자연강우에의존하였고시비는실시하지않았다. 매년 3월초에신초 (shoot) 가발생하기전광량확보를돕고신초생장을촉진시키기위하여지면에서 20cm 높이로묵은지상부를제거하였다 (Quinn and Macleod, 2003; Lee and Kim, 2005). 통계분석시험구배치는완전임의배치법 (completely randomized design) 으로적용하였고통계분석은 Statistical Analysis System (SAS) 9.4 프로그램 (SAS institute, 2016) 의 ANOVA를이용하여품종간출수와화서의형태적특성을비교분석하였으며평균간유의성검정은던컨의다중검정법 (Duncan s multiple range test) 5% 오차수준에서실시하였다. 결과및고찰총출수기간, 화경밀도및평균출수속도본연구에서전체실험기간중출수하지않았던 Gold Breeze 를제외하고총출수기간, 화경밀도및 MWH는통계적으로품종간유의한차이를보였다 (Table 3). 출수된공시재료 6품종의총출수기간조사결과 5-9주범위였으며 Kleine Fontäne > Strictus Common > Variegatus Gracillimus > Morning Light 순서로길었다 (Table 3). Kleine Fontäne 는 2017년 7월 25일공시재료중가장빨리출수하여 9월 19일까지 9주간장기간지속되었고 Morning Light 는가장늦은 10월 3일출수하여 10월 31일까지 5주간의짧은출수기간을보였다. Common 과 Strictus 는 9월 3일, 9월 10일출수하여모두 7 주간, Variegatus 와 Gracillimus 는 9월 24일출수하여 6주간의출수기간을보였다. Jensen et al.(2011) 의연구와같이본실 Horticultural Science and Technology 295

7 Table 3. Total heading period, peduncle density and mean weekly heading (MWH) of seven Miscanthus sinensis cultivars in the 2017 test Cultivar Total heading period z (weeks) Peduncle density y MWH x Gold Breeze - w - - Strictus Sep 10 - Oct 22 (7) 73.5 d v 11.0 e Morning Light Oct 3 - Oct 31 (5) 83.3 c 16.7 c Variegatus Sep 24 - Oct 29 (6) 70.0 d 12.3 d Gracillimus Sep 24 - Oct 29 (6) b 17.8 b Kleine Fontäne Jul 25 - Sep 19 (9) a 22.1 a Common Sep 3 - Oct 15 (7) 75.0 d 10.7 e z Total period of weeks from when the cultivar reached 40% heading from all plants until termination defined by Jensen et al. (2011) and Rural Development Administration (2012). y Total number of peduncles per plant. x Mean weekly heading: peduncle density divided by total heading period. w Gold Breeze did not bloom during the test period. v Different letters in each row indicate significant difference by Duncan s multiple range test at p < 험에서도첫서리가내리고최저기온이영하로내려가는 10월말을기점으로공시재료모두더이상의출수가진행되지않았다. 억새는자생지와환경조건이달라지면영양생장기의생육특성이다르게나타나는데 (Song et al., 2018) 공시재료중 Gold Breeze 는미국 Oregon 지역의 M. sinensis Strictus 군락에서우연실생으로육종된품종 (U.S. Patent, 2011) 으로현지에서는 9월말이나 10월초에화경이출현하는것으로알려져있다. 그러나본실험에서는 2013년정식후 2017년조사기간까지한차례도출수되지않은것으로보아지역적환경조건에따라출수특성차이가큰것으로생각되었다. 화경밀도는 개범위였으며 Kleine Fontäne 는식물 1본당총화경수가평균 199.3개로가장많았고 Common, Strictus, Variegatus 는각각 75개, 73.5개, 70개로가장적었다 (Table 3). 품종간비교결과 Kleine Fontäne > Gracillimus > Morning Light > Common Strictus Variegatus 순서로화경밀도가높았으며 Common 과비교하여 Kleine Fontäne, Gracillimus, Morning Light 는통계적으로유의하게높았다. MWH 는 10-25개범위였으며 Kleine Fontäne 는 22.1개로 MWH가가장빨랐고 Strictus 와 Common 은각각 10.9개, 10.7개로가장느렸다 (Table 3). 품종간비교한결과 Kleine Fontäne > Gracillimus > Morning Light > Variegatus > Strictus Common 순서로나타났으며 Common 과비교하여 Kleine Fontäne, Gracillimus, Morning Light, Variegatus 는통계적으로유의하게빨랐다. 억새의영양생장과생식생장에관한연구에의하면영양생장기간이상대적으로길고바이오매스축적량이많은대형종 (M. sacchariflorus) 은영양생장기간이상대적으로짧고조기출수하는소형종 (M. sinensis) 에비하여출수가늦은것으로보고되어있다 (Clifton-Brown et al., 2001; An et al., 2013; Song et al., 2018). 그러나본실험에서억새원예품종의경우상대적으로소형품종인 Gracillimus, Morning Light 에서대형품종인 Common, Strictus, Variegatus 보다출수시점이늦고출수기간이짧은상반된경향이나타났다. 화경밀도는소형품종이대형품종보다높았고 MWH도소형품종이빠른경향을보였다. 주간출수율, 출수피크타임, 출수집중도및출수패턴 Gold Breeze 를제외한 6품종의 WHR을분석한결과 Kleine Fontäne 는 7월말출수하여 9주간지속되었고 1주차 WHR 10.5% 를시작으로 3주차까지증가하였으며 4주차부터감소하기시작하여 5주차부터는 10% 이하로급격히감소하였다 (Fig. 2). Common 과 Strictus 는 9월초출수하여 7주간지속되었고 Kleine Fontäne 와유사한경향을보였다. 두품종모두 1주차 WHR은 10% 이하였고 2주차까지증가하였으며 3주차부터는감소하기시작하여 4주차부터 10% 이하로급격히감소하였다. 이와달리 Variegatus 는 9월말출수하여 6주간지속되었으며 1주차에 WHR이 39.8% 로높았으며 2주차까지상승하였고 296 Horticultural Science and Technology

8 A B C Fig. 2. Weekly heading rate (WHR) of three early heading pattern cultivars of Miscanthus sinensis that showed longer heading period of 7-9 weeks. (A) Kleine Fonta ne, (B) Common, and (C) Stictus. 3주차부터는 10% 이하로급격히감소하였다 (Fig. 3). 동일하게 9월말출수한 Gracillimus 도 6주간출수가지속되었는데 1주차 WHR이 50.6% 로공시재료중에서높은출수율을보였고 2주차부터는감소하였으며 4주차부터 10% 이하로급격히감소하였다. Morning Light 는 10월초출수하여 5주간지속되었고 1주차 WHR이 48.3% 로높은출수율을보였고 Gracillimus 와유사한경향을보였다. 출수피크타임, MHR 에대한품종간비교결과 WHR이가장높은 1차출수피크타임도달시기는출수후 1-3주사이였고 Gracillimus Morning Light > Strictus Variegatus Common > Kleine Fontäne 순서로빨랐다 (Table 4). 1차출수피크타임의 WHR은 % 까지나타났으며 Strictus > Gracillimus > Variegatus Morning Light > Kleine Fontäne > Common 순서로높았다. CHR 이 50% 이상되는 2차출수피크타임도달시기는출수후 1-3주사이였는데 Morning Light 는 1차에서 2차출수피크타임까지 1주일이소요된반면, 다른 5품종들은모두 1차피크타임과 2차피크타임이동시에나타났다 (Table 4). 2차출수피크타임의 CHR은 % 까지나타났고 Variegatus > Kleine Fontäne Morning Light > Strictus Common > Gracillimus 순서로높았으며품종간 CHR 차이가가장크게나타났다. CHR 이 75% 이상되는 3차출수피크타임도달시기는출수후 2-4주사이였으며 Variegatus Gracillimus > Strictus Morning Light Common > Kleine Fontäne 순서로빨랐고출수된공시재료모두총출수기간의반이지나기전 3차출수피크타임에도달하였다 (Table 4). 3차피크타임의 CHR은 % 까지나타났고 Morning Light > Kleine Fontäne > Variegatus > Strictus > Common > Gracillimus 순서로높았다. 3차출수피크타임의 CHR을소요주수로나눈 MHR은 % 까지나타났으며 Variegatus > Gracillimus > Morning Light > Strictus > Kleine Fontäne > Common 순서로높았다 (Table 4). Horticultural Science and Technology 297

9 A B C Fig. 3. Weekly heading rate (WHR) of three late heading pattern cultivars of Miscanthus sinensis that showed intensive WHR after simultaneous heading initiation with shorter heading periods of 5-6 weeks. (A) Variegatus, (B) Gracillimus, and (C) Morning Light. Table 4. Weekly heading rate (WHR), cumulative heading rate (CHR) and mean heading rate (MHR) of seven Miscanthus sinensis cultivars during inflorescence peak times Cultivar Peak I z Peak II y Peak III x WAH w WHR v (%) WAH CHR u (%) WAH CHR (%) MHR t (%) Gold Breeze - s Strictus a r c c 28.9 d Morning Light bc b a 31.5 c Variegatus bc a bc 44.0 a Gracillimus ab d e 37.7 b Kleine Fontäne cd b b 22.7 e Common d d d 27.8 d z Time at the highest weekly heading rate. y Time at more than 50% cumulative heading present. x Time at more than 75% cumulative heading present. w Weeks after heading. v Weekly heading rate: (number of peduncles per week/total number of peduncles) 100%. u Cumulative heading rate. Σ[WHR] until peak II. t Mean heading rate: CHR divided by WAH in peak III. s Gold Breeze did not bloom during the test period. r Different letters in each row indicate significant difference by Duncan s multiple range test at p < Horticultural Science and Technology

10 이상의결과를종합하여출수패턴을분석해보면 Kleine Fontäne, Common, Strictus 는 7월말에서 9월초사이출수하여조기출수의패턴이나타났고 Variegatus, Gracillimus, Morning Light 는 9월말에서 10월초사이출수하여만기출수의패턴을보였다 (Figs. 2 and 3). 출수시점이빠른조기출수패턴의품종 ( Kleine Fontäne, Common, Strictus ) 은출수초기에 WHR이높은경향이었으나만기출수패턴의품종에비해 1차, 2차, 3차출수피크타임도달시기가상대적으로늦고 MHR이낮았다 (Table 4). 출수시점이늦은만기출수패턴의품종 ( Variegatus, Gracillimus, Morning Light ) 은출수와동시에 WHR이높게나타났고 1차, 2차, 3차출수피크타임도달시기가빨랐으며 MHR도높았다 (Table 4). 한편, 공시재료모두 3차출수피크타임을지나면서 WHR이 10% 전후로급격히감소하였는데이는품종간출수시점에따라화서의캐노피형성시기가다를수있지만 3차출수피크타임까지는전체적인캐노피형성이완료되는것으로판단되었다. 화서색채색차계의 L * a * b * 값의 L은명도, a와 b는색좌표값으로 +a는적색 (red), -a는녹색 (green), +b는황색 (yellow), 그리고 -b는청색 (blue) 방향을나타낸다 (Kim and Kim, 2008). 엽색과화색은계절, 관리조건, 생육단계에따라변하게되며실내의경우는광원에따라서도다르게표현되기때문에고정된대표색을추출하기에는어려움이있다고보고되어있다 (Kim and Seo, 2013; Seo, 2014; Moon and Choi, 2014; Kim and Choi, 2015; Lee and Moon, 2015). 본연구에적용된억새원예품종화서의경우작은기관이밀집된구조이고일시에단일한색이표현되지않아측색시점을화서변화단계 (stage 1-3) 마다측정하였으며화서변화단계가진행될수록황색계열 (yellowish) 색상이발현되었다 (Table 5). 개화기인 stage 1에서나타난색채의주요부위는 spikelet이였고 Common, Strictus, Morning Light, Variegatus, Gracillimus 는적색계열 (reddish), Kleine Fontäne 는황록색계열 (yellowish green) 의색상이발현되었다. 적색계열의 Morning Light, Variegatus, Gracillimus 는 Common 보다적색이짙었고 Strictus 는유사하였으며명도차이는크지않았다 (Table 5). 종자성숙기인 stage 2에서나타난색채의주요부위는 spikelet 기부에서나타난털 (hair) 이었고기준색의 Common 과비교하여 Morning Light, Variegatus, Gracillimus 는색차이값 (ΔE*ab) 이크게나타났다 (Table 5). 적색계열의 Common, Strictus, Morning Light, Variegatus, Gracillimus 모두 stage 1에서나타났던적색이옅어졌고황색 Table 5. Characteristics of L * a * b * ( Lab color space) and color difference value (ΔE*ab) of inflorescence on seven Miscanthus sinensis cultivars from flowering season to seed shatter stage Cultivar Stage 1 z Stage 2 y Stage 3 x L a b ΔE*ab w L a B ΔE*ab L a b ΔE*ab Gold Breeze - v Strictus Morning Light Variegatus Gracillimus Kleine Fontäne Common RC u RC RC z Flowering stage. Spikelet color was measured. y Seed ripening stage. Hair color of spikelet was measured. x Seed shattering stage. Rachis color was measured. w ΔE*ab = L L a a b b. Just-noticeable difference of color was ΔE*ab 2.3. v Gold Breeze did not bloom during the test period. u Reference color: the inflorescence color of M. sinensis Common. Horticultural Science and Technology 299

11 이짙어졌으며명도에의한 ΔE*ab가크게나타났다. 종자탈립기인 stage 3로전환된후색채의주요부위는꽃대 (rhachis) 였는데출수된공시재료모두황색이더욱짙어졌으며품종간 ΔE*ab가가장작았다 (Table 5). Stage 1, stage 2에서는기준색과의색차를가시적으로확인이가능했지만 stage 3부터는기준색과의색차가크지않았으며측색결과동일한경향을확인하였다. 따라서화서의색채를가시성의평가요소로적용하기위해서는 stage 1과 stage 2에서발현되는색채를구분하여적용해야할것으로판단되었다. 화서의형태적특성본연구의공시재료는포장에서정식 5년차였고화서의형태적특성의조사시점은화서변화단계중종자성숙기 (stage 2) 였다. 화서의형태적특성을평가하기위하여초고와간장, 그리고초고와간장의거리비율인분리지수를측정하였다. 출수된공시재료 6품종의초고분포는 cm였으며 Strictus Common > Variegatus Gracillimus > Kleine Fontäne Morning Light 순서로높았고품종간최대 47.5cm의차이가나타났다 (Table 6). 간장은 cm까지분포하였으며 Strictus > Common > Variegatus Gracillimus > Kleine Fontäne Morning Light 순서로나타났고각품종의초고와유사하였다. 분리지수는 까지분포하였으며 Strictus > Common Morning Light Gracillimus > Variegatus > Kleine Fontäne 순서로컸다 (Table 6). Strictus 는초형의직립성이강한품종으로초고가높았지만간장도길어분리지수가 1.48로가장컸으며화서로식물체의캐노피가형성되었다. Kleine Fontäne 는 1.12로분리지수가가장작아초고와간장의차이가크지않는초형과화서가혼재된캐노피를형성하였다. 화서길이는 cm까지나타났고 Common > Kleine Fontäne Gracillimus Strictus Variegatus > Morning Light 순서였으며 Common 이 34.3cm로가장길었다 (Table 6). 화서폭은 cm까지나타났으며 Gracillimus Common Variegatus > Morning Light Strictus > Kleine Fontäne 순서로넓었다 (Table 6). Gracillimus 의화서폭은 31.3cm로가장넓었지만화서폭이가장좁은 Kleine Fontäne 를제외하면품종간화서폭은유사하였다. 화서장폭비는 까지나타났는데 Kleine Fontäne 를제외하면품종간큰차이는없었으며 Kleine Fontäne > Strictus Common Variegatus Morning Light Gracillimus 의순서로컸다 (Table 6). Kleine Fontäne 는화서폭이 6.0cm로가장좁았으며장폭비는 Table 6. Morphological characteristics of inflorescence on seven Miscanthus sinensis cultivars Cultivar PH z (cm) SL y (cm) DI x L w (cm) W v (cm) L/W ratio u RD t SD s Gold Breeze 57.5 d - r Strictus a q a 1.48 a 26.0 b 21.8 b 1.20 b 30.0 b 12.8 d Morning Light c d 1.24 b 20.8 c 23.5 b 0.89 b 24.0 cd 24.8 a Variegatus b c 1.21 bc 25.5 b 29.0 a 0.89 b 26.8 bc 21.0 b Gracillimus b c 1.29 b 26.3 b 31.3 a 0.84 b 27.3 bc 14.8 c Kleine Fontäne c d 1.12 c 27.3 b 6.0 c 4.62 a 22.3 d 10.8 e Common a b 1.29 b 34.3 a 29.8 a 1.15 b 33.8 a 14.5 cd z Plant height: height from bottom to top leaf in natural shape. y Stem length: height from bottom to neck of the raceme. x Dissociation index: the distinction of canopy between foliage and inflorescence. w Length: length of inflorescence in natural shape. v Width: maximum width of inflorescence in natural shape. u Length/width ratio. t Raceme density: number of racemes per inflorescence. s Spikelet density: number of spikelets per 3cm raceme. r Gold Breeze did not bloom during the test period. q Different letters in each row indicate significant difference by Duncan s multiple range test at p < Horticultural Science and Technology

12 4.62로길이가폭의 4배이상으로화서의직립성이강하게나타났다. Raceme 밀도는화서한개당 개를보였고 Common > Strictus > Gracillimus Variegatus > Morning Light > Kleine Fontäne 순서였으며화서길이가가장길었던 Common 은 33.8개로 raceme 밀도가가장높았다 (Table 6). Spikelet 밀도는 raceme 3cm 단위길이당 개까지분포하였으며 Morning Light > Variegatus > Gracillimus > Common > Strictus > Kleine Fontäne 순서였고 Morning Light 는 24.8개로 raceme 밀도는낮았지만 spikelet 밀도가가장높았다 (Table 6). 화서가시성평가화경밀도, MWH, 3차출수피크타임 CHR의출수특성 (Tables 3 and 4) 과분리지수, 화서길이, raceme 밀도의화서형태적특성 (Table 6) 대하여통계적등급에따라평균점수를산출하고화서의가시성을평가한결과평균 로출수된공시재료 6품종모두 scale 3(scale 1-5; 1 = poor quality, 3 = average quality, 5 = excellent quality) 이상을보였다 (Table 7). 화서가시성결정특성을각품종별로분석해보면 Common, Strictus, Variegatus, Gracillimus 는화서의형태적특성에의해, Kleine Fontäne, Morning Light 는출수특성에의해가시성이결정되는경향을보였다 (Table 7). Common 의화서가시성은평균 3.2였는데화경의밀도가낮고 MWH, 3차피크타임의 CHR도낮아화서의캐노피형성이늦었다. 그러나분리지수가크고화서길이가길며 raceme 밀도가높아출수특성 (2.7) 보다화서의형태적특성 (4.7) 이가시성을높이는주요인으로판단되었다. Stirctus 의화서가시성은평균 3.2였으며가시성결정특성이 Common 과유사하였다. Variegatus 의화서가시성은평균 3.1이었고화서의길이가길고 raceme의밀도도높았다. Gracillimus 의화서가시성은평균 3.4였는데화경의밀도는높았으나 3차출수피크타임 CHR이낮아캐노피형성이늦었던반면분리지수가크고화서의길이도길었다. 이와대조적으로 Kleine Fontäne 의화서가시성은평균 3.8이었는데분리지수가작아초형과화서의캐노피가혼재되어나타났고화서의길이에비하여 raceme의밀도가낮았다. 그러나화경의밀도가높고 MWH, 3차출수피크타임누적출수율도높아형태적특성 (3.0) 보다출수특성 (4.7) 이가시성을높이는주요인으로판단되었다 (Table 7). Morning Light 는공시재료중에서가장높 Table 7. Evaluation (1-5 scale) of inflorescence visibility based on heading characteristics and morphological characteristics of seven Miscanthus sinensis cultivars Cultivar Heading characteristics Morphological characteristics Inflorescence PD z MWH y CHR x Mean DI w L v RD u Mean visibility t Color s Gold Breeze - r Strictus reddish Morning Light reddish Variegatus reddish Gracillimus reddish Kleine Fontäne yellowish Common reddish z Penducle density: total number of peduncles per plant. y Mean weekly heading: total number of peduncles divided by heading period. x Cumulative heading rate in peak III. w Dissociation index. When DI > 1, or the larger number means more clear distinction of canopy between foliage and inflorescence. v Length: length of inflorescence in natural shape. u Raceme density: number of racemes per inflorescence. t Scale1-5: 1 = poor quality, 3 = average quality, 5 = excellent quality. Each item was evaluated from 1 to 5 points based on statistical significance. s The inflorescence color on spikelets in the flowering stage (stage 1). r Gold Breeze did not bloom during the test period. Horticultural Science and Technology 301

13 은 3차출수피크타임 CHR이나타났지만화서의길이가짧고 raceme의밀도가낮았다. 따라서, 본연구의억새원예품종들은품종마다출수특성과화서의형태적특성에서차이가나타남에따라다양한요인에의해화서의가시성이결정되는것으로분석되었다. 초록경관가치가우수하고다양한생육환경에잘적응하는관상용그래스인억새 (M. sinensis) 원예품종 7가지 ( Gold Breeze, Strictus, Morning Light, Varieagatus, Gracillimus, Kleine Fontäne, Common ) 의출수특성과화서의형태적특성을분석하고화서의가시성을평가하였다. 공시재료는 2013년시험포장에정식, 재배하였고 2017년 7월부터 2018년 2월까지데이터를수집하였다. Gold Breeze 를제외한 6개품종이출수하였는데 Kleine Fontäne 의출수기간이가장길었으며화경밀도도가장높았다. 출수패턴은조기와만기로구분되었으며조기출수패턴의품종 ( Kleine Fontäne, Common, Strictus ) 은출수초기에주간출수율 (WHR) 이높은경향이었으나출수피크타임에늦게도달했고출수집중도 (MHR) 도낮았다. 만기출수패턴의품종 ( Varieagatus, Gracillimus, Monring Light ) 은출수와동시에 WHR이높았고출수피크타임에일찍도달했으며 MHR도높았다. 화서변화단계를개화기 (stage 1), 종자성숙기 (stage 2), 종자탈립기 (stage 3) 로구분하였는데화서의색채는 stage 1에서적색계열 ( Strictus, Morning Light, Variegatus, Gracillimus, Common ) 과황록색계열 ( Kleine Fontäne ) 로구분되었다. Common (reference color) 과의화서색차이값 (ΔE*ab) 은 stage 1과 stage 2에서컸으며 stage 3에서는줄었다. 화서의형태적특성은초고, 간장, 분리지수, 길이, 폭, 장폭비, raceme 밀도, spikelet 밀도에서품종간유의한차이가있었다. 출수특성과형태적특성을바탕으로화서가시성결정특성을품종별로분석한결과 Common, Strictus, Variegatus, Gracillimus 는화서의형태적특성이두드러졌고 Kleine Fontäne, Morning Light 는출수특성이화서의가시성결정에기인한것으로나타났다. 본연구에서억새원예품종들의화서가시성은평균 을보였으며출수특성과화서의형태적특성의다양한요인에의해가시성이결정되는것으로분석되었다. 추가주요어 : 분리지수, 관상용그래스, 화경, 벼과, 주간출수율 Literature Cited An GH, Kim JK, Moon YH, Cha YL, Yoon YM, Koo BC, Park KG (2013) A now genotype of Miscanthus sacchariflorus Geodae-Uksae 1, identified by growth characteristics and a specific SCAR marker. Bioprocess Biosyst Eng 36: doi: /s An GH, Um KR, Lee JH, Jang YH, Lee JE, Yu GD, Cha YL, Moon YH, Ahn JW (2015) Flowering patterns of Miscanthus germplasms in Korea. Korean J Crop Sci 60: doi: /kjcs Association of Official Seed Analysts (AOSA) (1990) Rules for testing seeds. Seed Technol J 12:1-112 Bonin CL, Mutegi E, Snow AA, Miriti M, Chang H, Heaton EA (2017) Improved feedstock option or invasive risk? Comparing establishment and productivity of fertile Miscanthus giganteus to Miscanthus sinensis. Bioenergy Res 10: doi: /s Chen L, Ryu JS, Lee JS (2016) A study on analysis of colors applied to façade of modern commercial avenues in Korea and China. J Korean Soc Color Stud 30:5-17. doi: /jkscs Clifton-Brown JC, Lewandowski I, Andersson B, Basch G, Christian DG, Kjeldsen JB, Jorgensen U, Mortensen JV, Riche AB, et al (2001) Performance of 15 Miscanthus genotypes at five sites in Europe. Agron J 93: doi: /agronj x Darke R (2007) The encyclopedia of grasses for the livable landscapes. Timber Press, Portland, OR, USA, pp Davidson CG, Gobin SM (1998) Evaluation of ornamental grasses for the northern great plains. J Environ Hortic 16: Dougherty RF, Quinn LD, Endres AB, Voigt TB, Barney JN (2014) Natural history survey of the ornamental grass Miscanthus sinensis in the introduced range. Invasive Plant Sci Manag 7: doi: /ipsm-d Dougherty RF, Quinn LD, Voigt TB, Barney JN (2015) Response of naturalized and ornamental biotypes of Miscanthus sinensis to soil-moisture and shade stress. Northeastern Nat 22: doi: / Horticultural Science and Technology

14 Gao H, Liu J (2005) The ornamental grass species and their ornamental value and utilization. Grassland Turf 3:13-16 Greef JM, Deuter M, Jung C, Schondelmaier J (1997) Genetic diversity of European Miscanthus species revealed by AFLP fingerprinting. Genet Resour Crop Evol 44: doi: /a: Gunnell JD, Jerry LG, Richard MA (2015) Ornamental grasses in the landscape, A guide for the Intermountain West. University of Utah Extension, UT, USA Jensen E, Farrar K, Jones ST, Hastings A, Donnison I, Brown JC (2011) Characterization of flowering time diversity in Miscanthus species. Glob. Change Biol Bioenergy 3: doi: /j x Jensen E, Robson P, Norris J, Cookson A, Farrar K, Donnison I, Clifton-Brown J (2013) Flowering induction in the bioenergy grass Miscanthus sacchariflorus is a quantitative short-day response, whilst delayed flowering under long days increases biomass accumulation. J Exp Bot 66: doi: /jxb/ers346 Kim JM, Kim KS (2008) A study on floral color groups and ranges for cut flowers using by colorimeter. J Korean Soc Color Stud pp Kim KD, Kim YJ, Lee JM, Lee JH, Joo YK (2013) Seed treatment and plug production of ornamental grasses (Gramineae spp.). Weed Turf Sci 2: doi: /wts Kim KD, Lee JH, Joo YK (2015) Spring green-up and winter leaf discoloration of three ornamental grasses (Gramineae spp.). Weed Turf Sci 4: doi: /wts Kim YS, Choi SR (2015) Analysis of change in plants color according to temperature and humidity of wall greening in the eco plaza of the new government office building of Seoul. J Korean Soc Color Stud 29: doi: /jkscs Kim YS, Seo JH (2013) A comparative analysis on color by lighting of patterns in Begoniaceae commercially distributed in Korea. J Korean Soc Color Stud 27:5-11. doi: /jkscs Korea Forest Service (KFS) (2015) Illustrated grasses of Korea. Jinhan M&B Inc., Seoul, Korea, pp Korea Meteorological Administration (KMA) (2018) Weather Information. Accessed 1 March 2018 Korea Nation Arboretum (KNA) (2018) Korean Plant Names Index (KPNI). Accessed 12 March 2018 Lee CB (2003) Coloured flora of Korea. Hyang Mun Sa Publishing Co., Seoul, Korea, pp 434 Lee JP, Kim DH (2005) Improvement of green-up zoysiagrass and cool-season grass during early spring in Korea. Korean Turfgrass Sci 19: Lee JS, Moon EB (2015) Analysis on the foliar color of street trees in residential area of Gyeonggi-do province. J Korean Soc Color Stud 29:5-16. doi: /jkscs Meyer MH (2004) Miscanthus: Ornamental and invasive grass. HortScience 39:792. doi: /hortsci b Meyer MH, Tchida CL (1999) Miscanthus Anderss. Produces viable seed in four USDA hardness zones. J Environ Hortic 17: Missouri Botanical Garden (MBG) (2018) MBG Plant Finder. Accessed 12 March 2018 Moon EB, Choi HJ (2014) A study on the classification criteria of landscape for local color collection. J Korean Soc Design Cult 20: Quinn M, Macleod C (2003) Grasses scapes: Gardening with ornamental grasses. Ball Publishing, Batavia, IL, USA, pp Rural Development Administration (RDA) (2012) Standard book on research, investigation and analysis of agricultural science and technology. RDA, Korea, pp SAS institute (2016) SAS/STAT User s guide version 9.4. SAS Inst., Inc., Cary, NC, USA Seo JH (2014). Analysis on color change by seasonal in greenhouse cut rose. J Korean Soc Color Stud 28: doi: /jkscs Smith LS, Fellowes MDE (2015) The influence of plant species number on productivity, ground coverage and floral performance in grass-free lawns. Landscape Ecol Eng 11: doi: /s Sohn KH, Kwon HJ (2008) Study of dried Korean native plants using for floral cluster. Flower Res J 16: Song YS, Lee JE, Moon YH, Yu GD, Choi IS, Cha YL, Kim KS (2018) Changes of morphological and growth characteristics collected Miscanthus germplasm in Korea. Weed Turf Sci 7: doi: /wts Thetford M, Norcini JG, Ballard B, Aldrich JH (2009) Ornamental landscape performance of native and nonnative grasses under low-input conditions. HortTechnology 19: doi: /hortsci U.S. Department of Agriculture (USDA) (2018) Natural Resources Conservation Service Plant Database. Accessed 12 March 2018 US Patent (2011) Miscanthus plant named Gold Breeze. US PP22,311 P2 Wilson SB, Knox GW (2006) Landscape performance, flowering, and seed viability of 15 Japanese silver grass cultivars grown in Northern and Southern Florida. HortTechnology 16: doi: /horttech Wilson SB, Knox GW (2009) Landscape performance, flowering, and seed viability of 10 green fountain grass alternative grown in Northern and Southern Florida. HortTechnology 19: doi: /hortsci Wu J, Teng W, Wang Q (2006) Evaluation of ornamental characters of introduced drought-tolerant perennial ornamental grasses in spring. Hua Bei Nong Xue Bao 1:028 Horticultural Science and Technology 303