Influence of hydraulic properties of rootstocks and the rootstock-scion graft on water use and productivity of apple trees

This one year exploratory project investigated hydraulic architecture of apple dwarfing rootstocks. The hypothesis was that hydraulic conductance is correlated with rootstock vigor. A previous study of trees on three rootstocks in Israel showed that dwarfed trees used less water than un-dwarfed trees. Analysis showed that if the tree maintains leaf water potentials above minimum values, then this implies that the dwarfed trees have lower leaf conductance, which may also be the cause of dwarfing. The current project studied small 2-year old unworked rootstock trees, and full sized trees bearing commercial yields. In both cases hydraulic conductance was determined with two methods - the non-destructive evaporative flux (EF)-leaf water potential (L WP) method, and a destructive method in which water was forced through the plant at known pressure using the "high pressure flow meter" (HPFM). Detailed work allowed measurement of conductance of the rootstock-scion union. This was achieved both with the HPFM and with the EF-LWP methods, the former in the US and the latter in Israel. Direct measurements of leaf conductance were made, and carbon isotope ratios ( d ¹³ C) were determined for leaves sampled at the end of the season. The latter can indicate sustained differences in leaf conductance behavior. HPFM and EF-LWP methods did not give the same results. In the small plants results were similar in magnitude, but not significantly correlated. In large trees, EF- L WP measurements were a fraction of those obtained with the HPFM. The latter indicates that some of the xylem is not normally functional but transports water when pressurized. Additional experimental work targeted this result. Xylem was stained before and after perfusion with water at high pressure. This showed that at least for one rootstock a significant amount of xylem was blocked before perfusion. The "air method" for determining xylem vessel properties was improved and employed. Length, radius and density of xylem vessels of different rootstocks were found to be similar, and significant differences found were not clearly related to rootstock vigor. Measurements in the commercial orchard in Israel showed that the graft union in a dwarfing rootstock was a large obstacle for water transport (i.e. had a high resistance). This apparently led to low leaf conductance to water vapor, as indicated by lower d ¹³ C, which implies low internal CO ₂ concentrations. In the US orchard, d ¹³ C in 2001 was correlated with rootstock vigor, and significant differences were found in leaf conductance. However, the d ¹³ C differences were not observed in 2002, were opposite to those found in the Israeli orchard, and measurements of the graft union with the HPFM did not find large resistances. We speculate that the graft union is not necessarily a large impediment to water transport unless the scion starts to separate from the rootstock. It was concluded that significant differences in hydraulic conductance exist between different dwarfing rootstocks. These differences may be caused by differences in xylem properties and in the degree of cavitation, as well as resistance in the graft union. However, no general relationship to rootstock vigor was found. Therefore, hydraulic conductance alone cannot explain dwarfing, but may be one of two or more factors that lead to dwarfing. Future work should integrate more factors with hydraulic relations, e.g. nutrient and solute transport and production of hormones.

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Two measures of leaf capacitance: insights into the water transport pathway and hydraulic conductance in leaves

Functional Plant Biology ◽

10.1071/fp10183 ◽

2011 ◽

Vol 38 (2) ◽

pp. 118 ◽

Cited By ~ 50

Author(s):

Chris J. Blackman ◽

Tim J. Brodribb

Keyword(s):

Water Transport ◽

Lignin Content ◽

Leaf Tissue ◽

Dry Weight ◽

Hydraulic Conductance ◽

Leaf Water ◽

Transport Pathway ◽

Transpiration Stream ◽

Two Measures ◽

Key Indicators

The efficiency and stress tolerance of leaf water transport are key indicators of plant function, but our ability to assess these processes is constrained by gaps in our understanding of the water transport pathway in leaves. A major challenge is to understand how different pools of water in leaves are connected to the transpiration stream and, hence, determine leaf capacitance (Cleaf) to short- and medium-term fluctuations in transpiration. Here, we examine variation across an anatomically and phylogenetically diverse group of woody angiosperms in two measures of Cleaf assumed to represent bulk-leaf capacitance (Cbulk) and the capacitance of leaf tissues that influence dynamic changes in leaf hydration (Cdyn). Among species, Cbulk was significantly correlated with leaf mass per unit area, whereas Cdyn was independently related to leaf lignin content (%) and the saturated mass of leaf water per unit dry weight. Dynamic and steady-state measurements of leaf hydraulic conductance (Kleaf) agreed if Cdyn was used rather than Cbulk, suggesting that the leaf tissue in some species is hydraulically compartmentalised and that only a proportion of total leaf water is hydraulically well connected to the transpiration stream. These results indicate that leaf rehydration kinetics can accurately measure Kleaf with knowledge of the capacitance of the hydraulic pathway.

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SAFETY AND EFFICIENCY OF XYLEM WATER TRANSPORT IN TWO CASHEW (Anacardium occidentale L.) STRAINS AT THE SEEDLING STAGE

Jurnal Penelitian Tanaman Industri ◽

10.21082/jlittri.v18n4.2012.156-161 ◽

2020 ◽

Vol 18 (4) ◽

pp. 156

Author(s):

JOKO PITONO ◽

TSUDA MAKOTO

Keyword(s):

High Pressure ◽

Water Transport ◽

Applied Pressure ◽

Vessel Diameter ◽

Hydraulic Conductance ◽

Seedling Stage ◽

Wet Season ◽

Flow Meter ◽

Pressure Flow ◽

Xylem Vulnerability

ABSTRACT As cashew trees are grown by transplanting seedlings, the seedling often suffers from drought damaged due to prolonged dry season. Previous study found that the ability to maintain water transport in xylem related to drought resistant character. To determine whether there was trade-off between the ability to maintain water transport in xylem and an efficiency of water transport, differences in xylem vulnerability to dysfunction, hydraulic conductance, and the relationship to xylem vessel diameter were examined in two cashew strains. The xylem vulnerability to dysfunction was evaluated by the applied pressure which induced 50% loss of stem hydraulic conductivity (P 50 ). The hydraulic conductance on root, stem, and leaf were determined with High Pressure Flow Meter (HPFM). Variations in the P 50 values were found between A3-1 and Pangkep, whereas the values were 1.75 and 0.50 MPa, respectively. However, since there was no difference in the hydraulic conductance and the vessel diameter, the trade- off between the ability to maintain water transport in xylem and an efficiency of water transport did not occur in cashew. It was suggested that good combination of efficiency and safety of water transport enables A3-1 to strongly uptake soil water either in dry or wet season resulting in good adaptation to drought prone environment, and the P 50 value would be suitable parameter for evaluating drought tolerance of cashew at the seedling stage. Key words: cashew strain, vessel, xylem dysfunction, hydraulic conductance, droughtABSTRAK Pengembangan jambu mete secara transplanting sering diikuti cekaman kekeringan pada bibit akibat musim kering yang berkepanjangan. Studi awal memperlihatkan bahwa kemampuan xylem mempertahankan fungsi transportasi air merupakan karakter pertahanan penting terhadap cekaman kekeringan. Untuk mengetahui apakah terjadi kompensasi antara kemampuan pertahanan fungsi xylem dan tingkat efisiensi transportasi airnya dilakukan pengujian pada aspek kepekaan fungsi xylem, hantaran hidraulik, dan ukuran vesselnya. Kepekaan fungsi xylem ditentukan dari nilai tekanan udara yang menyebabkan kehilangan 50% hydraulic conductance (P 50 ). Nilai hydraulic conductance pada akar, batang, dan daun ditentukan dengan menggunakan metode High Pressure Flow Meter (HPFM). Hasil pengujian menunjukkan terdapat perbedaan nilai P 50 diantara dua strain jambu mete yang diuji, yakni secara berturut-turut 1,75 dan 0,50 MPa pada strain A3-1 dan Pangkep. Karena tidak disertai perbedaan pada hydraulic conductance dan ukuran vesselnya, maka disimpulkan tidak ditemukan nilai adanya mekanisme kompensasi antara kemampuan pertahanan fungsi xylem dan tingkat efisiensi pengangkutan air. Hal ini memungkinkan A3-1 tetap dapat menyerap air tanah secara cukup, baik pada musim kering maupun musim basah, dan mampu beradaptasi dengan baik di daerah rawan kekeringan. Dan nilai P 50 dapat dijadikan sebagai parameter representatif untuk evaluasi toleransi bibit jambu mete terhadap cekaman kekeringan. Kata kunci: strain jambu mete, vessel, fungsi xylem, hydraulic conductance, cekaman kekeringan

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The Influence of the Lignotuber on Hydraulic Conductance and Leaf Conductance in Eucalyptus behriana Seedlings

Functional Plant Biology ◽

10.1071/pp9950857 ◽

1995 ◽

Vol 22 (5) ◽

pp. 857 ◽

Cited By ~ 4

Author(s):

BA Myers

Keyword(s):

Water Potential ◽

Water Flow ◽

Leaf Water Potential ◽

Hydraulic Conductance ◽

Leaf Conductance ◽

Leaf Water ◽

Mature Trees ◽

Flow Through ◽

Transpirational Flow ◽

Stem Segments

Hydraulic conductances of stem segments and stem-plus-lignotuber segments were estimated for 3-year-old seedlings of the mallee eucalypt Eucalyptus behriana F. Muell. Stems of seedlings were cut underwater and either above or below the lignotuber. Cutting the stem of intact seedlings underwater and above the lignotuber resulted in rapid increases in leaf water potential (Ψ); 1.1 MPa in 10-15 min with a concomitant decrease in leaf conductance. Cutting the stem below the lignotuber did not significantly affect leaf Ψ or leaf conductance. Transpirational flow through whole seedlings and segments of seedlings was about 10-9 m3 s-1. The hydraulic conductance of the lignotuber (2.27 × 10-9 m3 s-1 Mpa-1) was about half that of the stem. This work suggests that resistance to water flow through the lignotuber accounts, in part, for the persistently low dawn Ψ of the foliage of mature trees of E. behriana.

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KETIDAKEFEKTIFAN KEBIJAKAN ANTI-DUMPING PRODUK IMPOR BAJA INDONESIA: SEBUAH ANALISIS AWAL

Buletin Ilmiah Litbang Perdagangan ◽

10.30908/bilp.v11i2.230 ◽

2017 ◽

Vol 11 (2) ◽

pp. 143-168

Author(s):

Aditya Paramita Alhayat

Keyword(s):

Government Regulation ◽

Best Practice ◽

Secondary Data ◽

Information Services ◽

Global Trade ◽

Trade Patterns ◽

Safeguard Measures ◽

The Us ◽

Before And After ◽

The Government

Meskipun Indonesia telah mengenakan tindakan anti-dumping terhadap beberapa jenis produk baja, namun impor produk tersebut masih meningkat. Salah satu kemungkinan penyebabnya adalah importasi melalui produk yang dimodifikasi secara tidak substansial atau melalui negara ketiga yang tidak dikenakan tindakan anti-dumping, yang dalam perdagangan internasional umum disebut sebagai praktik circumvention. Studi ini ditujukan untuk membuktikan bahwa circumvention mengakibatkan tindakan anti-dumping atas impor produk baja Indonesia tidak efektif dan untuk memberikan masukan berdasarkan praktik di negara lain supaya kebijakan anti-dumping Indonesia lebih efektif. Circumvention dianalisis dengan membandingkan pola perdagangan antara sebelum dan setelah pengenaan bea masuk anti-dumping (BMAD) menggunakan data sekunder dari Badan Pusat Statistik (BPS) maupun Global Trade Information Services (GTIS). Hasil analisis menunjukkan adanya indikasi kuat bahwa circumvention mengkibatkan pengenaan tindakan anti-dumping impor produk baja di Indonesia menjadi tidak efektif. Oleh karena itu, sangat penting bagi Pemerintah Indonesia untuk segera melakukan penyempurnaan terhadap Peraturan Pemerintah No. 34/2011 tentang Tindakan Antidumping, Tindakan Imbalan, dan Tindakan Pengamanan Perdagangan dengan memasukkan klausul tindakan anti-circumvention yang setidaknya mencakup bentuk-bentuk dan prosedur tindakan, sebagaimana yang telah dilakukan beberapa negara seperti: AS, EU, Australia, dan India. Although Indonesia has imposed anti-dumping measures on several types of steel products, the import of steel products is still increasing. One possible cause is that imports are made by non-substantial modification of product or through a third country which is not subject to anti-dumping measures, which is generally referred as circumvention practice. This study is aimed to prove that circumvention made Indonesian anti-dumping actions on the steel products ineffective. This also study provides recommendation for a best practice for other countries so that Indonesia's anti-dumping policy can be more effective. Circumvention was analyzed by comparing trade patterns between before and after the imposition of anti-dumping duty using secondary data from the Central Bureau of Statistics (BPS) and the Global Trade Information Services (GTIS). The results of the analysis indicate that circumvention became the reason why Indonesian anti-dumping measures on imported steel products are ineffective. Therefore, it is very important for the Government of Indonesia to immediately make amendments to the Government Regulation No. 34/2011 on Antidumping, Countervailing, and Safeguard Measures by adopting clauses of anti-circumvention. This can be done bycovering the forms/types and procedures of action, as has been implemented by several countries such as the US, EU, Australia, and India.

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Changes in Perceptions of Filipino Immigrants about Themselves and of Americans Before and After Coming to the United States

10.31124/advance.8107907 ◽

2019 ◽

Author(s):

Gremil Alessandro Naz

Keyword(s):

United States ◽

Symbolic Interaction ◽

The United States ◽

The Philippines ◽

Appraisal Theory ◽

American Values ◽

The Us ◽

Before And After ◽

Symbolic Interaction Theory ◽

Filipino Immigrants

This paper examines the changes in Filipino immigrants’ perceptions about themselves and of Americans before and after coming to the United States. Filipinos have a general perception of themselves as an ethnic group. They also have perceptions about Americans whose media products regularly reach the Philippines. Eleven Filipinos who have permanently migrated to the US were interviewed about their perceptions of Filipinos and Americans. Before coming to the US, they saw themselves as hardworking, family-oriented, poor, shy, corrupt, proud, adaptable, fatalistic, humble, adventurous, persevering, gossipmonger, and happy. They described Americans as rich, arrogant, educated, workaholic, proud, powerful, spoiled, helpful, boastful, materialistic, individualistic, talented, domineering, friendly, accommodating, helpful, clean, and kind. Most of the respondents changed their perceptions of Filipinos and of Americans after coming to the US. They now view Filipinos as having acquired American values or “Americanized.” On the other hand, they stopped perceiving Americans as a homogenous group possessing the same values after they got into direct contact with them. The findings validate social perception and appraisal theory, and symbolic interaction theory.

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Bioelectric Effect of a Microcurrent Toothbrush on Plaque Removal

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18168255 ◽

2021 ◽

Vol 18 (16) ◽

pp. 8255

Author(s):

Ji-Hyun Lee ◽

Jin-Hee Ha

Keyword(s):

Bacterial Flora ◽

Gingival Index ◽

Direct Electric Current ◽

Plaque Removal ◽

Bioelectric Effect ◽

Biofilm Removal ◽

Significant Difference ◽

The Us ◽

Before And After ◽

Previous State

This study evaluated the effectiveness of a microcurrent toothbrush (approved by the US Food and Drug Administration [FDA]), which employs a superimposed alternating and direct electric current, named as a Proxywave® technology, similar to the intensity of the biocurrent, in plaque removal and reducing gingivitis by biofilm removal through the bioelectric effect. This study enrolled 40 volunteers with gingivitis. Dental observations were made every two weeks, before and after the use of each toothbrush. We randomly assigned participants into two groups: one group used the Proxywave® toothbrush (PB) for two weeks followed by the control toothbrush (CB) for two weeks, while the other group used the CB for two weeks followed by the PB. The participants had a two-week washout period. If the toothbrush used earlier has had an effect on the bacterial flora in the oral cavity, this is to remove this effect and return it to its previous state. During each dental visit, we recorded plaque index (PI) and gingival index (GI) scores. The PI and GI scores were significantly lower in both the PB and the CB (p < 0.05). Considering the PI, there was no significant difference between the toothbrushes on all the surfaces. Considering the GI, the PB showed a significant decrease in the interproximal surface, compared to the CB (p < 0.05). The PB showed a significant decrease in the interproximal GI and had a beneficial effect in the interproximal area where the bristles could not reach. No adverse events were observed in the participants during the clinical trial. The microcurrent toothbrush is a device that can be safely used for plaque removal.

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Ethylene enhances root water transport and aquaporin expression in trembling aspen (Populus tremuloides) exposed to root hypoxia

BMC Plant Biology ◽

10.1186/s12870-021-02995-7 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Xiangfeng Tan ◽

Mengmeng Liu ◽

Ning Du ◽

Janusz J. Zwiazek

Keyword(s):

Gas Exchange ◽

Water Transport ◽

Populus Tremuloides ◽

Leaf Gas Exchange ◽

Hydraulic Conductance ◽

Root Hydraulic Conductance ◽

Trembling Aspen ◽

Expression Levels ◽

Root Hypoxia ◽

Exogenous Ethylene

Abstract Background Root hypoxia has detrimental effects on physiological processes and growth in most plants. The effects of hypoxia can be partly alleviated by ethylene. However, the tolerance mechanisms contributing to the ethylene-mediated hypoxia tolerance in plants remain poorly understood. Results In this study, we examined the effects of root hypoxia and exogenous ethylene treatments on leaf gas exchange, root hydraulic conductance, and the expression levels of several aquaporins of the plasma membrane intrinsic protein group (PIP) in trembling aspen (Populus tremuloides) seedlings. Ethylene enhanced net photosynthetic rates, transpiration rates, and root hydraulic conductance in hypoxic plants. Of the two subgroups of PIPs (PIP1 and PIP2), the protein abundance of PIP2s and the transcript abundance of PIP2;4 and PIP2;5 were higher in ethylene-treated trembling aspen roots compared with non-treated roots under hypoxia. The increases in the expression levels of these aquaporins could potentially facilitate root water transport. The enhanced root water transport by ethylene was likely responsible for the increase in leaf gas exchange of the hypoxic plants. Conclusions Exogenous ethylene enhanced root water transport and the expression levels of PIP2;4 and PIP2;5 in hypoxic roots of trembling aspen. The results suggest that ethylene facilitates the aquaporin-mediated water transport in plants exposed to root hypoxia.

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