Laser-induced Chlorophyll Fluorescence Ratio in Certain Plants Exhibiting Leaf Heliotropism

1997 ◽  
Vol 24 (2) ◽  
pp. 159 ◽  
Author(s):  
M. V. Sailaja ◽  
Y. Chandrasekhar ◽  
D. Narayana Rao ◽  
V. S. Rama Das
Keyword(s):  
Chlorophyll Fluorescence ◽  
Oryza Sativa L ◽  
Ricinus Communis ◽  
Hibiscus Cannabinus ◽  
Midday Depression ◽  
Photosystems I And Ii ◽  
Solar Tracking ◽  
Cleome Gynandra ◽  
Ricinus Communis L ◽  
Use Efficiency

Laser-induced F685/F720 chlorophyll fluorescence of intact leaves in solar tracking plants from Euphorbiaceae (Ricinus communis L.), Amaranthaceae (Amaranthus gangeticus L., Amaranthus viridis L.), Malvaceae (Hibiscus cannabinus L., Althaea rosea L.), Fabaceae (Dolichos lablab L.) Capparadaceae (Cleome gynandra L.) exhibited remarkable diurnal constancy in contrast to those of compass plants from Poaceae (Oryza sativa L.) and Amaranthaceae (Telanthera ficoides Moq.) with fixed leaf orientation. The F685/F720 ratio remained constant in both the diaheliotropic and paraheliotropic plants, but it decreased during midday in compass plants. The acquired spectra were analysed in terms of Gaussian parameters to determine the relative intensity of contribution of various bands; the data suggested a decrease in both the F685 and the F720 bands at 1230 h in compass plants while they remained unaltered in reorienting leaves. The typical midday depression in F685/F720 ratio observed in compass plants may be due to down-regulation of both photosystems, I and II. This unique behaviour of diurnal constancy in laser-induced F685/F720 suggests that the leaves of diaheliotropic plants maximise light-use efficiency throughout the day and avoid the hazard of midday depression of photosynthesis.

Laser-induced Chlorophyll Fluorescence Ratio in Certain Plants Exhibiting Leaf Heliotropism

1997 ◽  
Vol 24 (3) ◽  
pp. 407
Author(s):  
M. V. Sailaja ◽  
Y. Chandrasekhar ◽  
D. Narayana Rao ◽  
V. S. Rama Das
Keyword(s):  
Chlorophyll Fluorescence ◽  
Oryza Sativa L ◽  
Ricinus Communis ◽  
Hibiscus Cannabinus ◽  
Midday Depression ◽  
Photosystems I And Ii ◽  
Solar Tracking ◽  
Cleome Gynandra ◽  
Ricinus Communis L ◽  
Use Efficiency

Laser-induced F685/F720 chlorophyll fluorescence of intact leaves in solar tracking plants from Euphorbiaceae (Ricinus communis L.), Amaranthaceae (Amaranthus gangeticus L., Amaranthus viridis L.), Malvaceae (Hibiscus cannabinus L., Althaea rosea L.), Fabaceae (Dolichos lablab L.) Capparadaceae (Cleome gynandra L.) exhibited remarkable diurnal constancy in contrast to those of compass plants from Poaceae (Oryza sativa L.) and Amaranthaceae (Telanthera ficoides Moq.) with fixed leaf orientation. The F685/F720 ratio remained constant in both the diaheliotropic and paraheliotropic plants, but it decreased during midday in compass plants. The acquired spectra were analysed in terms of Gaussian parameters to determine the relative intensity of contribution of various bands; the data suggested a decrease in both the F685 and the F720 bands at 1230 h in compass plants while they remained unaltered in reorienting leaves. The typical midday depression in F685/F720 ratio observed in compass plants may be due to down-regulation of both photosystems, I and II. This unique behaviour of diurnal constancy in laser-induced F685/F720 suggests that the leaves of diaheliotropic plants maximise light-use efficiency throughout the day and avoid the hazard of midday depression of photosynthesis.

scholarly journals Comportamento do cafeeiro Apoatã em consórcio com culturas anuais

Bragantia ◽  
2004 ◽  
Vol 63 (2) ◽  
pp. 275-281 ◽  
Author(s):  
Edison Martins Paulo ◽  
Ronaldo Severiano Berton ◽  
José Carlos Cavichioli ◽  
Francisco Seiiti Kasai
Keyword(s):  
Zea Mays ◽  
Oryza Sativa ◽  
Arachis Hypogaea ◽  
Zea Mays L ◽  
Oryza Sativa L ◽  
Ricinus Communis ◽  
Coffea Canephora ◽  
Gossypium Hirsutum L ◽  
Ricinus Communis L ◽  
Arachis Hypogaea L

Estudou-se no Pólo Regional de Desenvolvimento Tecnológico dos Agronegócios da Alta Paulista, em Adamantina, SP, no período de 1989 a 1993 o comportamento do cafeeiro cv. Apoatã IAC 2258 (Coffea canephora Pierre ex Froehner), consorciado com espécies anuais cultivadas no verão. Adotou-se o delineamento estatístico de blocos ao acaso com cinco repetições. Os tratamentos consistiram de culturas de algodão (Gossypium hirsutum L.) var. IAC 20; amendoim (Arachis hypogaea L.) var. Tatu; arroz (Oryza sativa L.) var. IAC 165; mamona (Ricinus communis L.) var. Guarani e milho (Zea mays L.) var. IAC 100-B, semeadas a 50 cm da projeção da copa das plantas de café, e uma testemunha sem cultura intercalar. Avaliaram-se no período experimental a produtividade, a altura e o diâmetro do caule dos cafeeiros e a fitomassa e a produção das culturas intercalares. Os resultados mostraram que o consórcio do cafeeiro com as plantas de mamona, milho, algodão e amendoim diminuíram significativamente a produção de café em coco, mas não a altura e o diâmetro do caule do cafeeiro. A produção de café foi inversamente correlacionada com a produção de fitomassa das culturas intercalares.

scholarly journals Photosynthetic capacity and water use efficiency in Ricinus communis (L.) under drought stress in semi-humid and semi-arid areas

2017 ◽  
Vol 89 (4) ◽  
pp. 3015-3029 ◽  
Author(s):  
CLAUDIANA M. DOS SANTOS ◽  
LAURÍCIO ENDRES ◽  
VILMA M. FERREIRA ◽  
JOSÉ V. SILVA ◽  
EDUARDO V. ROLIM ◽  
...  
Keyword(s):  
Drought Stress ◽  
Water Use Efficiency ◽  
Water Use ◽  
Photosynthetic Capacity ◽  
Ricinus Communis ◽  
Arid Areas ◽  
Ricinus Communis L ◽  
Use Efficiency ◽  
Semi Arid

Ricinus communis L.: Water Use Efficiency, Carbon Assimilation and Water Relations on Deficit Irrigation

2019 ◽  
Vol 30 (5) ◽  
pp. 1-15
Author(s):  
Marília Carvalho ◽  
Francisvaldo Amaral Roza ◽  
Marcelo Schramm Mielke ◽  
Alex-Alan Furtado de Almeida ◽  
Luana Mahé Costa Gomes ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Water Relations ◽  
Deficit Irrigation ◽  
Ricinus Communis ◽  
Carbon Assimilation ◽  
Ricinus Communis L ◽  
Use Efficiency

scholarly journals Probing the floral developmental stages, bisexuality and sex reversions in castor (Ricinus communis L.)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sujatha Thankeswaran Parvathy ◽  
Amala Joseph Prabakaran ◽  
Thadakamalla Jayakrishna
Keyword(s):  
Developmental Stages ◽  
Ricinus Communis ◽  
Sex Expression ◽  
Pistil Abortion ◽  
Ricinus Communis L ◽  
Sex Reversion ◽  
Stage 4 ◽  
Meristem Development ◽  
Male Specific ◽  
First Time

AbstractCastor (Ricinus communis L) is an ideal model species for sex mechanism studies in monoecious angiosperms, due to wide variations in sex expression. Sex reversion to monoecy in pistillate lines, along with labile sex expression, negatively influences hybrid seed purity. The study focuses on understanding the mechanisms of unisexual flower development, sex reversions and sex variations in castor, using various genotypes with distinct sex expression pattern. Male and female flowers had 8 and 12 developmental stages respectively, were morphologically similar till stage 4, with an intermediate bisexual state and were intermediate between type 1 and type 2 flowers. Pistil abortion was earlier than stamen inhibition. Sex alterations occurred at floral and inflorescence level. While sex-reversion was unidirectional towards maleness via bisexual stage, at high day temperatures (Tmax > 38 °C), femaleness was restored with subsequent drop in temperatures. Temperature existing for 2–3 weeks during floral meristem development, influences sexuality of the flower. We report for first time that unisexuality is preceded by bisexuality in castor flowers which alters with genotype and temperature, and sex reversions as well as high sexual polymorphisms in castor are due to alterations in floral developmental pathways. Differentially expressed (male-abundant or male-specific) genes Short chain dehydrogenase reductase 2a (SDR) and WUSCHEL are possibly involved in sex determination of castor.

scholarly journals The root endophytic bacterial community of Ricinus communis L. resembles the seeds community more than the rhizosphere bacteria independent of soil water content

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Stephanie E. Hereira-Pacheco ◽  
Yendi E. Navarro-Noya ◽  
Luc Dendooven
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Plant Development ◽  
Bacterial Community Structure ◽  
Ricinus Communis ◽  
Ricinus Communis L ◽  
Endophytic Bacterial Community

AbstractRhizosphere and root endophytic bacteria are crucial for plant development, but the question remains if their composition is similar and how environmental conditions, such as water content, affect their resemblance. Ricinus communis L., a highly drought resistant plant, was used to study how varying soil water content affected the bacterial community in uncultivated, non-rhizosphere and rhizosphere soil, and in its roots. Additionally, the bacterial community structure was determined in the seeds of R. communis at the onset of the experiment. Plants were cultivated in soil at three different watering regimes, i.e. 50% water holding capacity (WHC) or adjusted to 50% WHC every two weeks or every month. Reducing the soil water content strongly reduced plant and root dry biomass and plant development, but had little effect on the bacterial community structure. The bacterial community structure was affected significantly by cultivation of R. communis and showed large variations over time. After 6 months, the root endophytic bacterial community resembled that in the seeds more than in the rhizosphere. It was found that water content had only a limited effect on the bacterial community structure and the different bacterial groups, but R. communis affected the bacterial community profoundly.

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