FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W157863577> ?p ?o ?g. }

• W157863577 abstract "The Australian native rainforest tree Macadamia integrifolia has been cultivated for its edible kernel since the early 1900's. High variability in yield and quality between trees, years and regions poses a significant problem for producers. To date, factors strongly correlated to yield have not been identified. There is little information on the N physiology of sub-tropical evergreen tree crops such as Macadamia. Three methods were used to evaluate N characteristics of mature, orchard grown Macadamia. Firstly, N compounds present in the xylem sap were characterised over two years from December 1999 to November 2001 in upper and lower canopy regions. Secondly, 15N fertiliser was applied to mature trees and 15N enrichment was determined in different tissues. Finally, 15NH4+ was injected into the xylem tissue of individual branches to identify N distribution patterns at particular times of the phenological cycle. There were distinct changes in xylem sap N and sugar concentration and composition with relation to phenology and tree management. Asparagine (ASN), glutamine (GLN), arginine (ARG), aspartate (ASP) and glutamate (GLU) comprised the majority of xylem sap amino N in mature Macadamia. A positive correlation was found between xylem sap sucrose and aspartate + glutamate content implying a metabolic link between these compounds. Canopy reduction is currently required in orchard grown Macadamia in order to maintain equipment access. Within one week, hedging of the lower canopy reduced xylem sap amino-N and sucrose concentrations by 5-6 fold and 2 fold respectively in the hedged portions of the canopy. Glutamine-N concentrations in the xylem sap increased 2-3 fold from February to May in this study suggesting that GLN may be a product of recent N assimilation. Close correlation between upper and lower canopy glutamine-N (GLN-N) concentrations up to 6 months after hedging suggest an even distribution of recently assimilated N throughout the canopy. Xylem sap glucose: fructose ratios close to 1:1 during flowering in spring and in the year following hedging suggest that sucrose is the primary C source of glucose and fructose. All trees were hedged at the same time so it is not possible to distinguish seasonal from treatment effects with certainty. Mature tree N uptake, transport and cycling were investigated using soil application of 15N labeled fertiliser. Highest mean 15N incorporation was detected in outer and mid canopy leaves 8 weeks after soil application. Decreases in 15N incorporation into outer and mid canopy leaves during vegetative dormancy suggest that soil derived N present in mature leaves remains part of a larger cycling pool of N. The close correlation between outer/mid canopy leaves and flush/flowers suggest the presence of a large mobile pool of N rather than discrete stores. 15N incorporation was significantly higher in actively growing tissues than in mature leaves or bark following introduction of 15NH4+ into individual branches using a novel xylem injection method. The relative N content and 15N incorporation patterns of outer, mid and inner canopy leaves suggest that reallocation of cycling N is the primary role of mature Macadamia leaves. Developing nuts that were prematurely abscised within 7 days of 15N injection had very low 15N incorporation. In contrast, 15N incorporation into nuts prematurely abscised 8-14 days after injection were similar to retained nuts implies that 15N transport to nuts ceased between 7 and 14 days prior to nut drop. It is likely that the reduced 15N incorporation is a result of reductions in xylem and phloem connectivity within the abscission zone resulting in a general loss of resource supply. Xylem sap collection, soil 15N application and 15N injection techniques allowed examination of mobile N forms and distribution at different temporal and spatial resolutions. The previously proposed role of mature leaves as N storage organs was revised and an alternative model of N cycling and reallocation is presented." @default.
• W157863577 created "2016-06-24" @default.
• W157863577 creator A5070718757 @default.
• W157863577 date "2003-01-01" @default.
• W157863577 modified "2023-09-26" @default.
• W157863577 title "Nitrogen and carbon relations in orchard grown Macadamia integrifolia trees" @default.
• W157863577 hasPublicationYear "2003" @default.
• W157863577 type Work @default.
• W157863577 sameAs 157863577 @default.
• W157863577 citedByCount "0" @default.
• W157863577 crossrefType "journal-article" @default.
• W157863577 hasAuthorship W157863577A5070718757 @default.
• W157863577 hasConcept C101000010 @default.
• W157863577 hasConcept C144027150 @default.
• W157863577 hasConcept C177924670 @default.
• W157863577 hasConcept C2778597767 @default.
• W157863577 hasConcept C2780753983 @default.
• W157863577 hasConcept C49799701 @default.
• W157863577 hasConcept C55493867 @default.
• W157863577 hasConcept C59822182 @default.
• W157863577 hasConcept C6557445 @default.
• W157863577 hasConcept C86803240 @default.
• W157863577 hasConceptScore W157863577C101000010 @default.
• W157863577 hasConceptScore W157863577C144027150 @default.
• W157863577 hasConceptScore W157863577C177924670 @default.
• W157863577 hasConceptScore W157863577C2778597767 @default.
• W157863577 hasConceptScore W157863577C2780753983 @default.
• W157863577 hasConceptScore W157863577C49799701 @default.
• W157863577 hasConceptScore W157863577C55493867 @default.
• W157863577 hasConceptScore W157863577C59822182 @default.
• W157863577 hasConceptScore W157863577C6557445 @default.
• W157863577 hasConceptScore W157863577C86803240 @default.
• W157863577 hasLocation W1578635771 @default.
• W157863577 hasOpenAccess W157863577 @default.
• W157863577 hasPrimaryLocation W1578635771 @default.
• W157863577 hasRelatedWork W2059154150 @default.
• W157863577 hasRelatedWork W2065589601 @default.
• W157863577 hasRelatedWork W2101443255 @default.
• W157863577 hasRelatedWork W2105204416 @default.
• W157863577 hasRelatedWork W2105793156 @default.
• W157863577 hasRelatedWork W2117288667 @default.
• W157863577 hasRelatedWork W2124714516 @default.
• W157863577 hasRelatedWork W2125349354 @default.
• W157863577 hasRelatedWork W2128197300 @default.
• W157863577 hasRelatedWork W2146739863 @default.
• W157863577 hasRelatedWork W2168444825 @default.
• W157863577 hasRelatedWork W2320255444 @default.
• W157863577 hasRelatedWork W2323642684 @default.
• W157863577 hasRelatedWork W2509457326 @default.
• W157863577 hasRelatedWork W2525248438 @default.
• W157863577 hasRelatedWork W2555915931 @default.
• W157863577 hasRelatedWork W2938314663 @default.
• W157863577 hasRelatedWork W3043966832 @default.
• W157863577 hasRelatedWork W791389185 @default.
• W157863577 hasRelatedWork W2131401813 @default.
• W157863577 isParatext "false" @default.
• W157863577 isRetracted "false" @default.
• W157863577 magId "157863577" @default.
• W157863577 workType "article" @default.