• Korean Journal of Plant Resources
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• v.26 no.4
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• pp.457-462
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• 2013

Molecular study were conducted to evaluate taxonomic identities of Echinochloa crus-galli (L.) Beauv. and Echinochloa crus-galli var. echinata (Willd.) Honda in Dokdo. Echinochloa crus-galli complex of two species 26 individuals analyse based on nuclear ribosomal DNA (ITS region) and cpDNA (trnH-psbA, trnL-F). At a result, two species were same sequence. Characters the length of the lemma and the length of the awn traits were identity of the species was unclear. According to, Taxonomy treatments that is based on existent morphological characters should thinks again. On the other hand, in the case of ITS, Echinochloa crus-galli (L.) Beauv. and Echinochloa crus-galli var. echinata (Willd.) Honda at the Dokdo forms from other clades with individuals that is collected at land area and Ulleungdo. These result is showing that is flowing independent evolution trends.

• Weed & Turfgrass Science
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• v.5 no.4
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• pp.181-186
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• 2016

Three Echinochloa species inhabit various crop fields with different soil moisture conditions. Therefore, a growthpouch test was conducted to investigate adaptive diversity of six Echinochloa species, three from Korea and three from USA, toosmotic stress by assessing shoot and root growths. Echinochloa crus-galli var. praticola showed the greatest tolerance to osmoticstress in both root ($GR_{50}=1316.3g\;PEG\;L^{-1}$) and shoot ($GR_{50}=212.2g\;PEG\;L^{-1}$) growths, while Korean E. oryzicola was mostsensitive to osmotic stress in both root ($GR_{50}=116g\;PEG\;L^{-1}$) and shoot ($GR_{50}=126.2g\;PEG\;L^{-1}$) growths. Root to shoot (R/S) ratioof Echinochloa crus-galli var. praticola increased with increasing osmotic stress, while that of Korean E. oryzicola decreased, suggestingthat R/S ratio is closely related to osmotic stress tolerance in Echinochloa species. Our results clearly demonstrate that E. crus-galli var.praticola maintains high R/S ratio even under high osmotic stress, which enables this species to well adapt to dry upland condition. Incontrast, while E. oryzicola fails to maintain sufficiently high R/S ratio, resulting in poor adaptability to dry upland condition.

• The Korean Journal of Ecology
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• v.17 no.3
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• pp.367-378
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• 1994

The germination responses of Echinochloa crus-galli (L.) Beauv. seeds to temperature were examined under the various thermal conditions. While almost all the seeds tested did not germinate immediately after collection, almost of the seeds which were stored for 7, 10, and 17 months showed very high germination percentages (85-95%) at their own constant temperatures between $16^{\circ}C\;and\;40^{\circ}C$. The total thermal time which was required for germination(10-70%) of Echinochloa crus-galli seeds ranged from 539Kh(degree Kelvin X hour) to 1,279Kh in accordance with the distribution function of thermal time, $F({\Theta})=1-[3D^{-3}({\Theta}-m+D)+1]^{-1/2}$, where m is 935Kh and D is 555Kh. Moist chilling treatment at $2^{\circ}C$ for 20 days increased the final germination percentage as well as the germination rate. In the increasing temperature(IT1 regime, E. crus-galli seeds started to germinate at $12^{\circ}C$. and showed greater germination rate with increasing temperatures, with the final germination percentage of 80%. On the other hand, in the decreasing temperature(DT1 regime, the seeds began to germinate at $12^{\circ}C$(10% germination) with the final germination percentage of 20%. An induced dormancy occurred at $4^{\circ}C$ in the DT regime.

• Weed & Turfgrass Science
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• v.3 no.3
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• pp.190-195
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• 2014

Echinochloa (L.) P. Beauv. includes some of the noxious weeds, causing a serious yield loss when they are dominant in the fields. Identification of the Echinochloa is very difficult because many interspecific and intraspecific forms of the species are found. However, it is important to identify the species exactly and to know the genetic diversity of the species for effective weed management. This study was conducted to identify and summarize the Echinochloa species by comparing the genetic variation and relationship among Korean Echinochloa species using SSR. The genetic diversity of 107 individuals, including seven species were assessed using five SSR markers. UPGMA dendrogram generated two clades (I and II) and clade II divided again into two subclades (II-1 and II-2) whereas the model based genetic structure proposed four subpopulations. The two subpopulations were corresponded to clades I and II-1 and the other two were arranged to clade II-2 of the UPGMA dendrogram. We have concluded that E. colona and E. glabrescens might have not distributed in Korea. The biological varieties, praticola and echinata, of E. crus-galli should be treated as E. crus-galli. Korean Echinochloa should be summarized with four species, i.e., E. oryzicola, E. crus-galli, E. esculenta, and E. oryzoides.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.821-832
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• 1997

The aim of this study was to separate or purify some bioactive compounds from flowers of alfalfa(Medicago sativa L.) and to test of the isolated compounds on alfalfa for their autotoxicity and on Echinochloa crus-galli for their allelopathy for seed germination and seedling weight. Using thin layer chromatography(TLC) of $CHCl_3$ extracts, the most inhibitory band to alfalfa seed germination was determined. Germination inhibition of this extract suggested a complex chemical interaction. Separation and purification of compounds with CHCl$_3$ extract of fresh alfalfa flowers were conducted by a silica gel TLC, and microcrystalline cellulose TLC(MCTLC), followed by droplet countercurrent chromatography(DCCC) bioassay. Preliminary identification was done by high perfomance liquid chromatography(HPLC) on the most inhibitory fractions in DCCC. Ferulic acid, caffeic acid, vanillic acid, rutin, narringin were identified in fraction 5 and ferulic acid, caffeic acid, vanillic acid, rutin, coumarin in fraction 6. The phytotoxicity of their individual compound was tested on alfalfa and Echinochloa crus-galli seed germination and seedling weight. Coumarin and ferulic acid showed the most inhibitory effect on alfalfa seed germination and Echinochloa crus-galli seedling fresh and dry weight. These compounds may be, at least in part, involved in autotoxicity and allelopathy.

• Weed & Turfgrass Science
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• v.4 no.3
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• pp.225-229
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• 2015

Echinochloa colona is one of the most problematic weeds in the paddy fields of the world. In recent years, this species is likely to be introduced in Korea due to global warming, the expansion of international trade including agricultural products, and increasing tourists. We tried to identify the species from Korean Echinochloa crus-galli and E. oryzicola in order to establish the control measures in case of the initial influx. For this study, Echinochloa colona collected from the National Plant Germplasm System, USA were examined and E. crus-galli and E. oryzicola were collected in Korea. It is, however, very difficult to identify for Echinochloa species using morphological characters because of numerous interspecific and intraspecific types found in nature. Thus, we barcoded the species using rbcL, matK, and ITS. All three markers identified E. colona very well from the others. ITS alone may be enough as a DNA barcode for E. colona identification, when considering cost and effectiveness. The barcode sequences were deposited to the National Center for Biotechnology Information database for public use.

• Korean Journal of Weed Science
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• v.17 no.1
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• pp.52-58
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• 1997

Rice (Oryza sativa L.) contains water-soluble substances that inhibit the germination of Echinochloa crus-galli. This study investigated the allelopathic potential of rice in which rice had been grown with E. crus-galli in the field. Extracts of forty-seven rice varieties were screened for allelopathic potential in the laboratory. Double distilled water was used as a control. Based on the germination percentage, the varieties may be classified in the following order of decreasing inhibition : Namweon(36%) and Gyehwa(38%) hulls extracts and Sambaeg(43%) and Seoan(46%) leaves extracts. In the comparison of allelopathic activity test between leaves and hulls extracts, hulls extracts contain more allelopathic toxic substances. In the effect of concentration treatment on the six levels of extract solutions(3, 6, 12, 25, 50, 100%, v/v) germination percentage was significantly inhibited as the extract concentration increased. The highest concentration(100%) caused the greatest reduction in E. crus-galli. Allelopathic potential effects were significantly different among the various varieties and between '94 and '95 year extracts. The results indicate that there are genetic differences among varieties for allelopathic potentiality on E. crus-galli. Allelopathic potential in the ecological aspects can be decided through variety selection.

• Korean Journal of Weed Science
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• v.16 no.3
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• pp.171-175
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• 1996

Seed occurrence patterns of Echinochloa crus-galli (L) P. Beauv. and Monochoria vaginalis (Burm. f.) Presl. were investigated in irrigated and rainfed rice cultures. There was not much difference in seed population of E. crus-galli between irrigated and rainfed fields, but M. vaginalis occurred in about 1.6-fold greater number in rainfed fields. In seed distribution patterns under the two conditions, about 50% and 30% of E. crus-galli and M. vaginalis, respectively, were found in the uppermost 5cm layer. Under both conditions M. vaginalis was distributed to a depth of 25cm, but distribution of E. crus-galli was only 15cm deep. Early rice transplanting brought about greater emergence of the two weeds than optimal or late transplanting. Emergence of the weeds was significantly greater in single cropping system of rice than in double cropping systems of rice followed by barley and/or strawberry.

• Korean Journal of Weed Science
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• v.8 no.1
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• pp.9-14
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• 1988

Three varieties of Echinochloa crus-galli (L.) Beauv. and five collections different in gross morphology from the E. crus-galli species were obtained in a lowland rice field located in Jukjeol-Ri, Soyang-Myeon, Wanju-Kun, Jeonbug to compare the ecological and physiological characteristics. There were great variations in seed dormancy, relative growth rates, days required to panicle emergence and panicle morphology among the collections. On the basis of the cluster analysis using the different characteristics, the collections were divided into three groups; E. crus-galli var. frumentaceae and its two ecotypcs, E. crus-galli var. echinata and its two ecotypes, and E crus-galli var. crus-galli and its one ecotype. There were differential responses in percent germination and post-germination growth of the collections to butachlor (2-chloro-2', 6'-diethyl-N-butoxymethyl acetanilide).

• Korean Journal of Weed Science
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• v.16 no.3
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• pp.194-199
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• 1996

Seed size and days required to reach specific growth stages were determined for Echinochloa crus-galli (L.) P. Beauv. varieties which are major grass species found in Korean paddy field and the results were compared with E. frumentacea (Roxb.) Link. In addition, responses of the Echinochloa species on preemergence herbicides (molinate, esprocarb, and mefenacet) were investigated with respect to time of application. One thousand seed weight of E. crus-galli var. oryzicola was about 3 times heavier than that of var. praticola, but was not significantly different that of E. frumentacea. Days requited to reach the 2.5 leaf-stage (LS) were 11, 13, and 14 days after seeding for E. frumentacea, E. crus-galli var. oryzicola, and E. crus-galli var. praticola, respectively. E. crus-galli var. praticola was more sensitive to molinate, esprocarb and mefenacet than var. oryzicola and the sensitivity of both the varieties decreased as the time of application LS was delayed. However, there was no great difference in the response for E. frumentacea when applied between 1.5 and 3.0 LS. In thiocarbamate hebicides esprocarb was more active to Echinochloa species than molinate and the higher the active ingredient of the herbicides, the greater was the activity to Echinochloa species. Differential susceptibility of Echinochloa species to the herbicides was not related to the seed size, but to the early growth stages at the time of herbicide application which were affected by the seed size.