Makesh Kumar, Bala

Paliwal, Kailash

English

University of Kentucky

University of Kentucky UKnowledge International Grassland Congress Proceedings 21st International Grassland Congress / 8th International Rangeland Congress Effects of Water and Nutrient Treatment on Gas Exchange and Water Relations of Two Casuarina equisetifolia Clones Bala Makesh Kumar Madurai Kamaraj University, India Kailash Paliwal Madurai Kamaraj University, India Follow this and additional works at: https://uknowledge.uky.edu/igc  Part of the Plant Sciences Commons, and the Soil Science Commons This document is available at https://uknowledge.uky.edu/igc/21/2-1/34 The 21st International Grassland Congress / 8th International Rangeland Congress took place in Hohhot, China from June 29 through July 5, 2008. Proceedings edited by Organizing Committee of 2008 IGC/IRC Conference Published by Guangdong People's Publishing House This Event is brought to you for free and open access by the Plant and Soil Sciences at UKnowledge. It has been accepted for inclusion in International Grassland Congress Proceedings by an authorized administrator of UKnowledge. For more information, please contact UKnowledge@lsv.uky.edu. 　 Multifunctional Grasslands in a Changing World 　 Volume Ⅰ 　 瞯 ]329　 瞯Grasslands/Rangelands Resources and Ecology ——— Soil Quality and Plant NutritionEffects of water and nutrient treatment on gas exchange and water relations of two Casuarinaequiseti folia clonesB . Makesh K umar and K ailash Paliw alDepartment o f Plant Sciences , School o f Biological Sciences , Madurai K amaraj University , Madurai 625 021 India .E‐mail : bala .makeshkumar＠ gmail .comKey words : Casuarina equiseti f olia , nutrient treatment , water relations , gas exchangeIntroduction The relative success of a plant , both in an evolutionary sense and in terms of biomass productivity , depends on itsability to sequester and efficiently utilize soil resources that often are scarce . Nitrogen ( N ) and water are considered to be theresources most of ten limiting survival , reproduction , or grow th , although macro‐or micro‐nutrients , oxygen , physical space ,or other soil factors also may be important in some circumstances . The ecophysiological responses of plants to fluctuations inavailable water and N , therefore , have been and will continue to be important subjects of research ( Evans , １９８９) .Methods Two Casuarina equiseti f olia clones ( CH and TCR ) were grown in the pots and the pots received two differentnitrogen treatments and water treatments starting from July to December ２０００ . Photosynthesis and WUE of the clones weremeasured seasonally and diurnally to determine different response of the clones .Results and discussion Photosynthesis and stomatal conductance were well correlated in our study in both clones ( Figure １ ) ; r‐values were in excess of ０畅５ . The slopes and intercepts of the two linear regressions were nearly identical . However , the dataset for �TCR�contained more values in the upper range of photosynthesis ( A ) and stomatal conductance ( g ) . The resultsshowed that physiological processes in foliage of the Casuarina clones respond differently to water stress . Genotypic andpopulation level difference in photosynthetic rate and water relations have been reported within hardwood genera or species( Abrams and Knapp １９８６ ; Furukawa et al . , １９９０ ) . Based on the earlier reports and from the present study , it can beconcluded that high intrinsic rates of photosynthetic rate , light control of stomatal water loss , high WUE , and osmoticadjustment to cellular desiccation are all very desirable for the grow th of the tree species . The physiology of �CH�appears tobe more susceptible to extreme drought than does that of �TCR�. These results could lead to the conclusion that �TCR�wouldbe a better choice for high biomass production under non irrigated in grassland ecosystem condition than �CH�.Figure 1 L inear regression o f photosynthesis (A ) vs . stomatal conductance ( g ) f or a) CH and b) TCR clones o f Casuarinaequisetifolia .Data f rom all treatment combination and f rom seasonal and diurnal measurements .ReferencesEvans , J .R . １９８９ . Photosynthesis and nitrogen relationships in leaves of C３ plants . Oecologia , ７８ : ９‐１９ .Abrams , M .D . and Knapp , A .K . １９８６ . Seasonal water relations of three gallery forest hardwood species in northeastKansas . For . Sci . ３２ : ６８７‐６９６ .Furukawa , A . , Park , S‐Y . and Fujinuma , Y . １９９０ . Hybrid poplar stomata unresponsive to changes in environmentalconditions . T rees , ４ : １９１‐１９７ .CH-Clone TCR-Clone - 20 ~-=- L-ow_ W_ a-te_r_: -Lo_w_ N ______ _ w 18 •LowWater:High N 1: 16 "-HighWater:LowN • .. •~" .,, 0 14 ... High Water : Hi!;j,h ~ /' •• ., ,.v'",... .. E 12 ~ . ..,. ~ "'l. • -ti.. :::::1. • ,!i .:, ti.,..7.• t. en 10 ._'a.~..<"~ ... -~ 8 •• t. " • £ 6 1~ ' ? °cri. ,.•~ 6 • C: J:,)-L( ~ -'~~ .. t ~ 4 •y. • '~ 0 0 •• 0 2 _...- • o O r2=0.615 ~ o +--"~~"'-~--~---------~ 0.0 0.1 0.2 0.3 0.4 0.5 0.6 Stomata! Conductance(mol.m·2 .s-1) b) 

Effects of Water and Nutrient Treatment on Gas Exchange and Water Relations of Two \u3cem\u3eCasuarina equisetifolia\u3c/em\u3e Clones

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Effects of Water and Nutrient Treatment on Gas Exchange and Water Relations of Two \u3cem\u3eCasuarina equisetifolia\u3c/em\u3e Clones

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