• Title/Summary/Keyword: dormancy

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Germination Responses of Echinochloa crus - galli Seeds to Temperature (온도에 대한 돌피(Echinochloa crus-galli) 종자의 발아반응)

  • 이호준;성미선;류병혁
    • 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.

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Presown Seed Treatments to Promote Seed Germination of Zoysiagrass (Zoysia japonica) (한국잔디 종자의 발아율 향상을 위한 파종전 종자처리)

  • 전병삼;강진호;조상철;권혁식;류영섭
    • Korean Journal of Plant Resources
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    • v.14 no.2
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    • pp.175-181
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    • 2001
  • Dormancy of intact zoysiagrass seeds hinders its seed propagation in which presowing seed treatment must be done to overcome it. The study was done to remodel the presowing treatments of zoysiagrass seeds by determining the treatment effects of seedcoat softening, prechilling, drying and combined light treatment with them or during germination stage. Seedcoat softening with different chemicals (NaOH 20%, KOH 20%, $H_2SO_4\;8M, acetone 20%) and periods (10, 30, 60 min.), prechilling with different periods at 3$^{\circ}C$, and drying with 4 hours at 35$^{\circ}C$ was done. Light sources were also applied with 660 nm red LED light, commercial fluorescent and incandescent light and darkness. Germination test was done in alternative day and night temperature of 35 and 2$0^{\circ}C$ to check the daily germination rates. With seeds treated with NaOH 20% for 30 minutes, red and incandescent light showing similar responses inclined their germination rates compared to dark conditions. Drying resulted in its higher rate than non-drying but fluorescent light treatment forced during drying more enhanced the rate than red light. While mean germination rate considering all the seedcoat softening treatment periods was the greatest in $H_2SO_4$ in comparison with NaOH, KOH and acetone, NaOH treatment for 30 minutes showed the best rate among the all the treatment levels. In the conditions of sowing them to no-mulching field, presowing treatment procedure of zoysiagrass seeds was remodeled: the seedcoat softening treatment with NaOH 20% for 30 minutes was done, washed, and chilled at 3$^{\circ}C$ for 2 weeks before dried under 4 hour fluorescent light illumination at 35$^{\circ}C$.

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The ptimum temperatures during cultivation period of Gastrodia elata according to growth stages (천마 생육단계별 변온에 의한 최적온도 및 재배기간)

  • Kim, Chang-Su;Kim, Hyo-Jin;Seo, Sang-Young;Kim, Hee-Jun;Lee, Wang-Hyu
    • Journal of Mushroom
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    • v.16 no.2
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    • pp.90-95
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    • 2018
  • This study was carried out to investigate the optimum temperature and the cultivation period according to the different growth stages of Gastrodia elata (G. elata). The growth period for the indoor cultivation of G. elata is divided into four stages that require specific temperatures during the enlargement of the tuber. The optimum temperatures and cultivation periods during the growth stages of G. elata were observed to be $20^{\circ}C$ for 30 days during the mycelial growth stage (MGS), $25^{\circ}C$ for 120 days during the tuber formation stage (TFS), $6-24^{\circ}C$ for 60 days during the tuber enlargement stage (TES), and $5^{\circ}C$ for 30 days during the dormant stage (DS). The total cultivation period was shortened by 120 days in the indoor cultivation facilities by reduction of 30 days from the mycelial growth stage, addition of 30 days to the tuber formation stage, and reduction of 120 days from the dormancy stage as compared to the outdoor field cultivation. These results provide a basis for a growth model that permits year-round cultivation of G. elata.

Weedy Rice Control by No-tillage Direct Seeding on Flooded Paddy Field (무경운 담수표면산파에 의한 잡초성벼 방제)

  • 정남진;윤영환;김정곤;강양순
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.45 no.3
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    • pp.195-198
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    • 2000
  • Weedy rice has typical characters such as easy shattering, dormancy, and longevity. These characters let it undergo the winter and occur year by year, It is very difficult to control weedy rice once the field have contaminated with its seeds. Therefore, the control method for weedy rice was focused on the no-tillage direct seeding in this experiment. The germination ability of seeds shattered on the soil surface in the next spring was 92.7% in weedy rice, and 4.3% in cultivated rice. The possible depth of weedy rice emergence were 1.5cm, 3.0cm and 6.8cm in no-tillage, wet seeding and dry seeding paddy field, respectively. The paddy field contaminated with weedy rice was maintained as no-tillage, and then irrigated in early spring (April 15). We could induce weedy rice on the soil to emerge with irrigation, and then kill by using non-selective herbicide, paraquat. Weedy rice was controled 92.2% of total emerged by this method. After seedling establishment of cultivated rice, molinate, thiobencarb, oxadiazon, dithiopyr, butachlor were soil-applied to suppress the emergence of weedy rice seeds buried in the soil. Oxadiazon was the most effective to repress the weedy rice among soil-applied herbicides tested. The highest control value was 96.4% as the result of combination of paraquat and oxadiazon.

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Effect of Light, $GA_3$, $KNO_3$ Treatments on the Germination of Chilean Wild Flower (칠레 야생화의 발아율에 미치는 광조건 그리고 $GA_3$, $KNO_3$ 처리 효과)

  • Choi, In-Lee;Lee, Dong-Jun;Lee, Kyoung-Soo;Son, Jin-Sung;Choi, Kyung;Park, Kwang-Woo;Kang, Ho-Min
    • Journal of Bio-Environment Control
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    • v.21 no.1
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    • pp.45-49
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    • 2012
  • Chilean wild flower seeds showed low germination rate and lacked germination uniformity. This experiment was conducted to find out the effects of light conditions, $GA_3$ (50 mg/L, 100 mg/L, 200 mg/L) and $KNO_3$ (0.1%, 0.2%, 0.4%) treatments on germination of five species of Chilean wild flower seeds. The seeds of $Schizanthus$ $candidus$, $Schizanthus$ $hookerii$, and $Schizanthus$ $litoralis$ did not germinated in light condition. The others did not show a significant different germination rate under light and dark conditions. The germination rate of $Mimulus$ $luteus$, $Schizanthus$ $candidus$, $Schizanthus$ $hookerii$ increased 2.3, 5.6, and 3.2 times compared with control, respectively in $GA_3$-200 mg/L treatment, but that of $Rhodophiala$ $ananuca$ enhanced slightly in $GA_3$-50 mg/L treatment. Those results suggested that the germination rate of Chilean wild flower seeds enhanced by $GA_3$ treatment that is very efficient in breaking seed dormancy.

Characteristics of Seed Structure and Seedling Development in Polygonatum odoratum Druce (둥굴레의 종자(種子) 구조(構造)와 출아(出芽) 특성(特性))

  • Kang, Jin-Ho;Kim, Dong-Il;Ryu, Yeong-Seop;Bae, Kee-Soo;Han, Kyung-Soo
    • Korean Journal of Medicinal Crop Science
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    • v.6 no.2
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    • pp.102-107
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    • 1998
  • Solomon's seal (Polygonatum odoratum) seedlings raised through its seeds can replace the rhizomes impelling higher cost for transplanting, This experiment was done to determine the seed characteristics and the germinating processes to give some information on bulk production of seedlings using the seeds. The external or internal morphology of seeds or seedlings grown in lab. or greenhouse was examined mainly with stereomicroscope. The external shape of Solomon's seal seed was hard seed-coat and orthotropous ovule with linear type embryo stretching to the center of seed. Germination proceeded through the several steps. The lower part of seed embryo having the primordia of bulbil and roots first grew before the bulbil and roots was developed from the primordia. The lower part of embryo was enlarged toward the endosperm of seed as soon as seed germinated. Then epicotyl was formed on the apex of bulbil. The epicotyl was elongated after at least 6-week chilling treatment for breaking its dormancy and the first leaf shape was affected by light intensity given during seedling emergence. The bulbil was the first organ of the rhizome used as tea or herb medicine.

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Effects of $GA_3$ on Seed Germination and Seedling Survival Rate of Acanthopanax senticosus Maxim. (가시오갈피의 $GA_3$처리에 따른 종자발아와 유묘생존)

  • Li, Cheng-Hao;Lim, Jung-Dae;Kim, Myong-Jo;Yu, Chang-Yeon
    • Korean Journal of Medicinal Crop Science
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    • v.11 no.3
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    • pp.207-211
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    • 2003
  • This experiment was carried out to investigate the effects of $GA_{3}$ and cold stratification as presown treatments on seed germination, seedling emergence and final survival rate of Acanthopanax senticosus Maxim. Seeds collected 145 days after-ripening period followed by 10 days of cold stratification was effective in promoting germination. Dehisced seeds treated with 500 ppm of $GA_{3}$ for 3 days was also effective in promoting germination. However, seedling emergence rate remained low in both treatment. Seedling emergence rate was higher for seeds germinated in Heungnong-Bio and Klasman-Bio than in vermiculite, perlite, vermiculite-perlite mixture, or sand. After 40 days of cold stratification, seedling emergence was significantly higher in the 500 ppm $GA_{3}$ treatment than nontreatment for both dehisced and non-dehisced seeds. However, for dehisced seeds, $GA_{3}$ treatment before sowing resulted in decreased final seedling survival rate.

Effects of Environmental Factors on the Stability and Vegetation Survival in Cutting Slope of Forest Roads (임도 절토 비탈면의 안정과 식생활착에 미치는 환경인자의 영향)

  • Jung, Won-Ok
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.4 no.2
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    • pp.74-83
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    • 2001
  • The purpose of this study was investigate to the influence of forest roads characteristics and environment factors on the soil erosion, stability and vegetation survival of cut slope in forest roads. The results obtained could be summarized as follows; 1. The correlated factors between slope erosion and variables in cut slope were altitude, convex, degree of slope, length of slope and soil depth. In the stepwise regression analysis, length of slope and soil hardness was a high significant and its regression equation was given by -89.6136 + 15.0667X14 + 16.6713X15($R^2$ = 0.6712). 2. The main factors influencing the stability of cut slope were significant in order of coverage, middle, convex, length of slope and north, and its discriminant equation was given by -1.019 + 0.064X22 - 0.808X8 - 0.622X24 + 0.742X11 - 0.172X14 - 0.545X6 ($R^2$ = 0.793). 3. The centroids value of discriminant function in the stability and unstability estimated to 1.244 and -1.348, respectively. The boundary value between two groups related to slope stability was -0.1038. The prediction rate of discriminant function for stability evaluation of was as high as 91.3%. 4. The dominant species of invasion vegetation on the cut slope consist with Carex humilis, Agropyron tsukushiense var. transiens, Calamagrostis arundinacea, Miscanthus sinensis var. purpurascens, and Ixeris dentata in survey area. The rate of vegetation invasion more increased by time passed. 5. The life form of invasion vegetation in cut slop showed to $H-D_1-R_{2,3}-e$ type of the hemicryptophyte of dormancy form, dissem inated widely by wind and water of dissminule type, moderate extent and narrowest extent of radicoid type, erect form of growth form. 6. The correlated factors between forest enviroment and coverage appeared north, passage years and middle position of slope at 5% level. The forest environment factors influencing the invasion plants in survey area were shown in order to altitude, passage years, rock(none), forest type(mixed) and stone amount. The regression equation was given by 17.5228 - 0.0911X3 + 3.6189X28 15.8493X22 19.8544X25 + 0.3558X26 ($R^2$ = 0.4026).

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Transcriptional and Mycolic Acid Profiling in Mycobacterium bovis BCG In Vitro Show an Effect for c-di-GMP and Overlap between Dormancy and Biofilms

  • Cruz, Miguel A. De la;Ares, Miguel A.;Rodriguez-Valverde, Diana;Vallejo-Cardona, Alba Adriana;Flores-Valdez, Mario Alberto;Nunez, Iris Denisse Cota;Aceves-Sanchez, Michel de Jesus;Lira-Chavez, Jonahtan;Rodriguez-Campos, Jacobo;Bravo-Madrigal, Jorge
    • Journal of Microbiology and Biotechnology
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    • v.30 no.6
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    • pp.811-821
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    • 2020
  • Mycobacterium tuberculosis produces mycolic acids which are relevant for persistence, recalcitrance to antibiotics and defiance to host immunity. c-di-GMP is a second messenger involved in transition from planktonic cells to biofilms, whose levels are controlled by diguanylate cyclases (DGC) and phosphodiesterases (PDE). The transcriptional regulator dosR, is involved in response to low oxygen, a condition likely happening to a subset of cells within biofilms. Here, we found that in M. bovis BCG, expression of both BCG1416c and BCG1419c genes, which code for a DGC and a PDE, respectively, decreased in both stationary phase and during biofilm production. The kasA, kasB, and fas genes, which are involved in mycolic acid biosynthesis, were induced in biofilm cultures, as was dosR, therefore suggesting an inverse correlation in their expression compared with that of genes involved in c-di-GMP metabolism. The relative abundance within trehalose dimycolate (TDM) of α-mycolates decreased during biofilm maturation, with methoxy mycolates increasing over time, and keto species remaining practically stable. Moreover, addition of synthetic c-di-GMP to mid-log phase BCG cultures reduced methoxy mycolates, increased keto species and practically did not affect α-mycolates, showing a differential effect of c-di-GMP on keto- and methoxy-mycolic acid metabolism.

Variables that Affect the Satisfaction of Brazilian Women with External Breast Prostheses after Mastectomy

  • Borghesan, Deise Helena Pelloso;Gravena, Angela Andreia Franca;Lopes, Tiara Cristina Romeiro;Brischiliari, Sheila Cristina Rocha;Demitto, Marcela de Oliveira;Agnolo, Catia Millene Dell;Carvalho, Maria Dalva de Barros;Pelloso, Sandra Marisa
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.22
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    • pp.9631-9634
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    • 2014
  • Background: : In 2012, the breast cancer estimate worldwide stood at 1.67 million new cases, these accounting for 25% of all types of cancer diagnosed in women. For 2014, 57,120 new cases are expected, with a risk estimated at 56.1 cases for every 100,000 women. The objective of this study was to analyze the satisfaction regarding the use of external breast prostheses by women undergoing mastectomy. Materials and Methods: This cross-sectional study was conducted with 76 women who used an external breast prosthesis (EBP), registered in the services of the Cuiaba Center for Comprehensive Rehabilitation, Mato Grosso, Brazil, from 2009 to 2012. Data were collected from the records of women who had requested the opening of a process of external breast prosthesis concession. Results: Satisfaction with the EBP was identified in 56.6% of the women. Those satisfied with the EBP reported that its weight was not annoying (p<0.01). Although the women felt body sensations of stitches, pains, pulling, dormancy and phantom limb, they are satisfied with the EBP. The variable related to the displacement of the breast prosthesis during activity of everyday life has demonstrated that even though the women have reported the possibility of displacements, they are satisfied with the EBP. The satisfaction with the use of external breast prosthesis did not affect the sexuality of the women with mastectomy. Conclusions: Learning the specificities of the EBP, taking into consideration the satisfaction of its use, allows the rehabilitation team, by listening to their clientele more attentively, following up this woman throughout her life journey, supporting and guiding the best way of use, with an eye to her personal, emotional and social life, as well as to her self-esteem.