Resistance to water flow through leaves of Coffea arabica is dominated by extra-vascular tissues

2004 ◽  
Vol 31 (12) ◽  
pp. 1161 ◽  
Author(s):  
Antonio Gascó ◽  
Andrea Nardini ◽  
Sebastiano Salleo
Keyword(s):  
Low Temperatures ◽  
Coffea Arabica ◽  
Vascular System ◽  
Membrane Damage ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Flow Through ◽  
Frame Work ◽  
Coffea Arabica L ◽  
Made In

The leaf hydraulic conductance (Kleaf) of Coffea arabica L. was measured for shoots exposed to non-lethal temperature stress or to a freeze–thaw cycle, and compared with Kleaf of non-stressed samples (controls). Exposure to temperatures below 6°C for 1 h caused measurable damage to the functional integrity of cell membranes as shown by increased membrane leakiness to electrolytes. A 1 : 1 relationship was found to exist between relative electrolyte leakage and relative Kleaf suggesting that membrane damage caused Kleaf to increase. Low temperatures did not cause membrane disruption as shown by the comparison of chilled samples with frozen–thawed ones. In frozen leaves, membranes were extensively disrupted and both electrolyte leakiness and Kleaf increased 5-fold. Low temperatures did not induce alterations of the hydraulic properties of the leaf vascular system, as revealed by measurements of Kleaf after up to 500 cuttings of minor veins were made in the leaf blade of control and chilled leaves. Calculations showed that 62–75% of leaf hydraulic resistance resided in the extra-vascular water pathway. Results are discussed within the frame work of our current understanding of leaf hydraulic architecture as well as in terms of plant adaptation to extremes in temperature.

scholarly journals Dehydrins (LTI29, LTI30, COR47) from Arabidopsis thaliana expressed in Escherichia coli protect Thylakoid membrane during freezing

2013 ◽  
Vol 78 (8) ◽  
pp. 1149-1160 ◽  
Author(s):  
Vladan Bozovic ◽  
Jan Svensson ◽  
Jürgen Schmitt ◽  
Carsten Kohn
Keyword(s):  
Low Temperatures ◽  
Protein Concentration ◽  
Gene Families ◽  
Thylakoid Membranes ◽  
Protein Expression Level ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Mrna And Protein Expression

As the name dehydrins implies, these proteins are typically expressed in response to dehydration which can be caused by drought, osmotic stress or freezing temperatures 1. In general, dehydrins occur in plants as multi-gene families. Four Arabidopsis dehydrins (LTI29, ERD14, COR47 and RAB18) have been tested for protection of thylakoid membranes during freeze thaw cycle in vitro. 2,3 Our firstly reported results show that dehydrins LTI29, ERD14, COR47 have cryoprotective activity while RAB18 did not protect the thylakoid membranes at low temperatures. The cryoprotective activity reached a maximum of 50% to 60% at protein concentration of 140-250 ?g/ml in the assay. A contribution of dehydrins to freezing tolerance in vivo is supported by the observation of Nylander et al. (2001)4 that LTI29 and COR47 are cold induced at mRNA and protein expression level.

SISTEMA DE PRODUCCIÓN DE CAFÉ (Coffea arabica L.) EN LA COMUNIDAD DEL CERRO CUATE, ILIATENCO, GUERRERO

2018 ◽  
Vol 11 (10) ◽  
Author(s):  
A. Delgado-Alvarado
Keyword(s):  
Coffea Arabica ◽  
El Sistema ◽  
Coffea Arabica L

Objetivo: Analizar el proceso de producción y comercialización de café en la comunidad del Cerro Cuate, Iliatenco, en la región de la Montaña de Guerrero, México.Diseño/Metodología/aproximación: el trabajo se realizó por; 1) investigación documental), 2) selección del área de estudio, 3) Entrevista estructurada con preguntas abiertas a 22 cafeticultores, soportada con la técnica de encuesta seccional y la herramienta de cédulas de entrevistas, y 4) análisis de la información. El tamaño de muestra se definió por el método de muestreo por conveniencia, y la selección de las unidades de análisis por la técnica bola de nieve. Resultados: El sistema de producción de café que predominó fue el sistema rústico de montaña, intercalado con plátano y frutales. La máxima productividad de las plantaciones se alcanza de 5.5 a 7.5años de edad, la renovación de plantas la hacen a los 12 años. El rendimiento de café fue de 3.7 kg por planta por año. La producción del café la realizan principalmente hombres (77.3%), entre 56 y 70años de edad. La venta se realiza en la presentación de café capulín a granel a intermediarios, a la ARIC, a CAFECO, a la Unión de Ejidos y a la Organización Mixtrui.Limitaciones del estudio/implicaciones: Se da una propuesta de mejora para favorecer el proceso de producción, beneficio y comercialización del café.Hallazgos/conclusiones: Coffea arabica es el principal café que se cultiva, con las variedades Typica, Caturra, Mundo Novo, Garnica y Bourbón. Los factores que limitan su producción y calidad son faltade planeación en manejo del cultivo y no contar con asesoría técnica.

Deposição da calda de pulverização em diferentes volumes vegetativos de Coffea arabica L.

2017 ◽  
Vol 12 (1) ◽  
pp. 69 ◽  
Author(s):  
Felipe Santinato ◽  
Renato Adriane Alves Ruas ◽  
Carlos Diego Silva ◽  
Rouverson Pereira Da Silva ◽  
Victor Afonso Reis Gonçalves ◽  
...  
Keyword(s):  
Coffea Arabica ◽  
Para Determinar ◽  
Coffea Arabica L

A disposição dos ramos e sobreposição das folhas em plantas de café dificultam a penetração da calda pulverizada. Portanto, para determinar o volume de calda adequado, é importante verificar o estado de enfolhamento da lavoura antes da aplicação. Objetivou-se com este trabalho, avaliar a deposição de caldas de pulverização em lavouras de café aplicadas em diferentes volumes vegetativos. Os tratamentos foram dispostos seguindo esquema de parcelas subdivididas em cada volume vegetativo (5.000; 7.500; 10.000 e 17.500 m<sup>3</sup> ha<sup>-1</sup>). Sendo as parcelas cinco volumes de calda (150, 300, 450, 600 e 750 L ha<sup>-1</sup>) e as subparcelas três posições no dossel do cafeeiro (terço superior, médio e inferior) com quatro repetições. Nos quatro volumes vegetativos estudados, não ocorreu interação significativa (p&gt;0,05) entre o volume aplicado e os diferentes volumes vegetativos. Porém, os volumes vegetativos de 5.000,0 e 17.500,0 m<sup>3</sup> ha<sup>-1</sup> a deposição foi crescente com aumento das vazões, o que pode ser atribuído a densidade foliar. Não foi verificada diferença estatística (p&gt; 0,05), entre as médias de deposição nos diferentes terços (alturas) no dossel das plantas de café, nos volumes vegetativos 5.000,0 m<sup>3 </sup>ha<sup>-1</sup>, 10.000,0 m<sup>3 </sup>ha<sup>-1</sup> e 17.500,0 m<sup>3 </sup>ha<sup>-1</sup>. Contudo, no volume de 7.500,0 m<sup>3 </sup>ha<sup>-1</sup> houve maior deposição no terço mediano em relação ao terço inferior. A deposição é maior à medida que aumenta o volume de calda aplicado. Em plantas com menor densidade foliar, há incremento na deposição. A deposição é maior no terço mediano em relação ao terço inferior.

Pengelolaan Pemangkasan Tanaman Kopi Arabika (Coffea arabica L.) di Kebun Blawan, Bondowoso, Jawa Timur

2016 ◽  
Vol 4 (3) ◽  
pp. 266
Author(s):  
Vinsensia Febrina Sianturi ◽  
Ade Wachjar
Keyword(s):  
Coffea Arabica ◽  
Coffea Arabica L

<p><em>Kopi merupakan salah satu komoditas perkebunan yang memiliki nilai ekonomi yang cukup tinggi</em><em>. </em><em>Kegiatan magang bertujuan mempelajari teknik budidaya</em><em> </em><em>tanaman</em><em> </em><em>dan</em><em> p</em><em>engelolaan</em><em> </em><em>perkebunan kopi, mempelajari dan menganalisis permasalahan yang dihadapi di lapangan mengenai pengelolaan pemangkasan serta solusi mengatasinya.</em><em> P</em><em>emangkasan </em><em>bertujuan </em><em>agar pohon tetap rendah sehingga mudah perawatannya, </em><em>dan </em><em>membentuk cabang-cabang produksi yang baru.</em><em> </em><em>Kegiatan magang dilaksanakan di Kebun Blawan, Bondowoso, Jawa Timur</em><em>,</em><em> mulai bulan Februari sampai dengan Juni 2014.</em><em> </em><em>Pengumpulan data </em><em>primer diperoleh melalui </em><em>pengamatan dan praktik kerja secara langsung meliputi kegiatan pemeliharaan tanaman yaitu pemangkasan lepas panen (pengamatan cabang-cabang tanaman, tinggi tanaman, jumlah tunas yang tumbuh)</em><em>, sedangkan data sekunder </em><em>diperoleh melalui </em><em>laporan manajemen perusahaan. </em><em>A</em><em>nalisis </em><em>data </em><em>yang dilakukan secara</em><em> deskriptif, rata-rata dan persentase</em><em>. Pemangkasan yang dilakukan</em><em> </em><em>termasuk dalam kategori pemangkasan ringan.</em><em> Tanaman kopi </em><em>yang memiliki kondisi cabang yang merata dan seimbang sangat mempengaruhi </em><em>hasil </em><em>taksasi</em><em> produksi</em><em>.</em><em> Banyak cabang harus dipangkas karena cabang-cabang yang sudah tua dan terserang penyakit. Setelah melakukan pemangkasan, tanaman menghasilkan tunas-tunas baru</em><em>.</em><em></em></p>

scholarly journals Unveiling a unique genetic diversity of cultivated Coffea arabica L. in its main domestication center: Yemen

2021 ◽  
Author(s):  
C. Montagnon ◽  
A. Mahyoub ◽  
W. Solano ◽  
F. Sheibani
Keyword(s):  
Genetic Diversity ◽  
Genetic Distance ◽  
Coffea Arabica ◽  
Genetic Improvement ◽  
The World ◽  
Genetic Clusters ◽  
Domestication Process ◽  
Almost All ◽  
Coffea Arabica L ◽  
Cup Quality

AbstractWhilst it is established that almost all cultivated coffee (Coffea arabica L.) varieties originated in Yemen after some coffee seeds were introduced into Yemen from neighboring Ethiopia, the actual coffee genetic diversity in Yemen and its significance to the coffee world had never been explored. We observed five genetic clusters. The first cluster, which we named the Ethiopian-Only (EO) cluster, was made up exclusively of the Ethiopian accessions. This cluster was clearly separated from the Yemen and cultivated varieties clusters, hence confirming the genetic distance between wild Ethiopian accessions and coffee cultivated varieties around the world. The second cluster, which we named the SL-17 cluster, was a small cluster of cultivated worldwide varieties and included no Yemen samples. Two other clusters were made up of worldwide varieties and Yemen samples. We named these the Yemen Typica-Bourbon cluster and the Yemen SL-34 cluster. Finally, we observed one cluster that was unique to Yemen and was not related to any known cultivated varieties and not even to any known Ethiopian accession: we name this cluster the New-Yemen cluster. We discuss the consequences of these findings and their potential to pave the way for further comprehensive genetic improvement projects for the identification of major resilience/adaptation and cup quality genes that have been shaped through the domestication process of C. arabica.

scholarly journals Sustainable Development of Chitosan/Calotropis procera-Based Hydrogels to Stimulate Formation of Granulation Tissue and Angiogenesis in Wound Healing Applications

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3284
Author(s):  
Muhammad Zahid ◽  
Maria Lodhi ◽  
Zulfiqar Ahmad Rehan ◽  
Hamna Tayyab ◽  
Talha Javed ◽  
...  
Keyword(s):  
Wound Healing ◽  
Blood Vessels ◽  
Granulation Tissue ◽  
Chorioallantoic Membrane ◽  
Calotropis Procera ◽  
Connective Tissues ◽  
Blood Capillaries ◽  
Chick Chorioallantoic Membrane ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle

The formation of new scaffolds to enhance healing magnitude is necessarily required in biomedical applications. Granulation tissue formation is a crucial stage of wound healing in which granulation tissue grows on the surface of a wound by the formation of connective tissue and blood vessels. In the present study, porous hydrogels were synthesized using chitosan incorporating latex of the Calotropis procera plant by using a freeze–thaw cycle to stimulate the formation of granulation tissue and angiogenesis in wound healing applications. Structural analysis through Fourier transform infrared (FTIR) spectroscopy confirmed the interaction between chitosan and Calotropis procera. Latex extract containing hydrogel showed slightly higher absorption than the control during water absorption analysis. Thermogravimetric analysis showed high thermal stability of the 60:40 combination of chitosan (CS) and Calotropis procera as compared to all other treatments and controls. A fabricated scaffold application on a chick chorioallantoic membrane (CAM) showed that all hydrogels containing latex extract resulted in a significant formation of blood vessels and regeneration of cells. Overall, the formation of connective tissues and blood capillaries and healing magnitude decreased in ascending order of concentration of extract.

scholarly journals Effect of freeze–thaw cycle on physical and mechanical properties and damage characteristics of sandstone

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Longxiao Chen ◽  
Kesheng Li ◽  
Guilei Song ◽  
Deng Zhang ◽  
Chuanxiao Liu
Keyword(s):  
Mechanical Properties ◽  
Shear Failure ◽  
Triaxial Compression ◽  
Physical And Mechanical Properties ◽  
Freeze Thaw ◽  
Damage Characteristics ◽  
Large Pore ◽  
Natural Rock ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle

AbstractRock deterioration under freeze–thaw cycles is a concern for in-service tunnel in cold regions. Previous studies focused on the change of rock mechanical properties under unidirectional stress, but the natural rock mass is under three dimensional stresses. This paper investigates influences of the number of freeze–thaw cycle on sandstone under low confining pressure. Twelve sandstone samples were tested subjected to triaxial compression. Additionally, the damage characteristics of sandstone internal microstructure were obtained by using acoustic emission (AE) and mercury intrusion porosimetry. Results indicated that the mechanical properties of sandstone were significantly reduced by freeze–thaw effect. Sandstone’ peak strength and elastic modulus were 7.28–37.96% and 6.38–40.87% less than for the control, respectively. The proportion of super-large pore and large pore in sandstone increased by 19.53–81.19%. We attributed the reduced sandstone’ mechanical properties to the degenerated sandstone microstructure, which, in turn, was associated with increased sandstone macropores. The macroscopic failure pattern of sandstone changed from splitting failure to shear failure with an increasing of freeze–thaw cycles. Moreover, the activity of AE signal increased at each stage, and the cumulative ringing count also showed upward trend with the increase of freeze–thaw number.

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