Leaf Water Relations and Gas Exchange in Relation to Forage Production in Four Asiatic Bluestems 1

Crop Science ◽  
1982 ◽  
Vol 22 (5) ◽  
pp. 1036-1040 ◽  
Author(s):  
P. I. Coyne ◽  
J. A. Bradford ◽  
C. L. Dewald
2016 ◽  
Vol 402 (1-2) ◽  
pp. 191-209 ◽  
Author(s):  
Anabela A. Fernandes-Silva ◽  
Álvaro López-Bernal ◽  
Timóteo C. Ferreira ◽  
Francisco J. Villalobos

HortScience ◽  
2012 ◽  
Vol 47 (3) ◽  
pp. 403-409 ◽  
Author(s):  
Vicente Gimeno ◽  
James P. Syvertsen ◽  
Inma Simon ◽  
Vicente Martinez ◽  
Jose M. Camara-Zapata ◽  
...  

Previous work on citrus trees has shown that an interstock, grafted between the rootstock and scion combination, not only can improve tree growth, longevity, fruit production, and quality, but also can increase salinity tolerance. This research was designed to evaluate flooding responses of 2-year-old ‘Verna’ lemon trees [Citrus limon (L.) Burm.; VL] either grafted on ‘Sour’ orange (C. aurantium L.; SO) rootstock without an interstock (VL/SO) or interstocked with ‘Valencia’ orange (C. sinensis Osbeck;VL/V/SO) or with ‘Castellano’ orange (C. sinensis Osbeck; VL/C/SO). Well-watered and fertilized trees were grown under greenhouse conditions and half were flooded for 9 days. At the end of the flooded period, leaf water relations, leaf gas exchange, chlorophyll fluorescence parameters, mineral nutrition, organic solutes, and carbohydrate concentrations were measured. Leaf water potential (Ψw), relative water content (RWC), net CO2 assimilation rate (ACO2), and stomatal conductance (gS) were decreased by flooding in all the trees but the greatest decreases occurred in VL/V/SO. The Ci/Ca (leaf internal CO2 to ambient CO2 ratio), Fv/Fo (potential activity of PSII) and Fv/Fm (maximum quantum efficiency) ratios were similar in flooded and non-flooded VL/SO and VL/C/SO trees but were decreased in VL/V/SO trees by flooding. Regardless of interstock, flooding increased root calcium (Ca), iron (Fe), copper (Cu), and manganese (Mn) concentration but decreased nitrogen (N) and potassium (K) concentration. Based on the leaf water relations, gas exchange, and chlorophyll parameters, ‘Verna’ lemon trees interstocked with ‘Valencia’ orange had the least flooding tolerance. Regardless of interstock, the detrimental effect of flooding in ‘Verna’ lemon trees was the leaf dehydration which decreased ACO2 as a result of non-stomatal factors. Lowered ACO2 did not decrease the leaf carbohydrate concentration. Flooding decreased root starch in all trees but more so in VL/V/SO trees. Sugars were decreased by flooding in roots of interstocked trees but were increased by flooding in VL/SO roots suggesting that the translocation of carbohydrates from shoots to roots under flooded condition was impaired in interstocked trees.


2009 ◽  
Vol 166 (5) ◽  
pp. 467-476 ◽  
Author(s):  
Mª Jesús Sánchez-Blanco ◽  
Sara Álvarez ◽  
Alejandra Navarro ◽  
Sebastián Bañón

2009 ◽  
Vol 45 (1) ◽  
pp. 93-106 ◽  
Author(s):  
E. E. M. PASSOS ◽  
C. H. B. A. PRADO ◽  
W. M. ARAGÃO

SUMMARYDaily courses of leaf gas exchange and leaf water potential (Ψleaf) of green dwarf coconut palm (Cocos nucifera) were measured in irrigated plantations on the wet coastal plateau and in a dry semi-arid area of northeast Brazil. At both sites, significant correlations were obtained between stomatal conductance (gs) and vapour pressure deficit (VPDair), Ψleaf and VPDair, leaf transpiration (E) and gs, and E-Ψleaf. Despite these similar relationships between sites, stronger correlations involving gs-VPDair and E-Ψleaf were found at the semi-arid site, where whole-plant hydraulic conductance (gp) was correlated significantly with VPDair. In addition, at the semi-arid site, only, the net photosynthesis (PN) was not correlated with E and Ψleaf, and the intrinsic water use efficiency (WUEi) was disconnected from VPDair and Ψleaf. The different behaviour of leaf gas exchange and Ψleaf between sites was probably caused by low gs in response to high VPDair at the semi-arid site. Our results indicate potential for significant alterations in the pattern of leaf gas exchange during future climatic changes with increasing temperature and concomitant increases in VPDair. The atmospheric water stress will probably reinforce the strength of connection among water relation variables (E, Ψleaf, gs, gp, and VPDair), but it will disrupt the linear relationship between net CO2 assimilation and leaf water relations such as PN-E, PN-Ψleaf, WUEi-VPDair and WUEi-Ψleaf.


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