HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Lynch, J. Articles by Rodriguez H., N. S. Search for Related Content PubMed Articles by Lynch, J. Articles by Rodriguez H., N. S. Agricola Articles by Lynch, J. Articles by Rodriguez H., N. S.

Photosynthetic Nitrogen-Use Efficiency in Relation to Leaf Longevity in Common Bean

Dep. Horticulture, Pennsylvania State Univ., University Park, PA, 16802
ICA Palmira, Programa de Frutales, Apartado Aereo 233, Palmira, Colombia

^* Corresponding author (jlynch{at}psupen.psu.edu).

Nitrogen deficiency is an important limitation to bean (Phaseolus vulgaris L.) production in the tropics. The ability of a leaf to utilize N for photosynthetic C assimilation (leaf N-use efficiency) may be element of genetic adaptation to low N soils. We tested the hypotheses that (i) leaf N-use efficiency is related to leaf longevity, and (ii) shoot architecture influences the relationship of leaf N-use efficiency and leaf longevity. Four genotypes that have contrasting shoot architectures (determinate bush, indeterminate bush, indeterminate prostrate, and indeterminate climbing) were grown in duplicate experiments in Colombia. At frequent intervals, the third and eighth leaves to appear on the main stem were analyzed for CO₂ assimilation and N content. Daily CO₂ assimilation and leaf N content, which were highly correlated, peaked soon after leaf expansion and declined steadily until leaf abscission. Leaf N duration and cumulative leaf CO₂ assimilation were highly correlated. Leaf longevity was highly correlated with leaf N duration and significantly correlated with cumulative leaf CO₂ assimilation. Leaf longevity was highly negatively correlated with leaf N-use efficiency expressed as cumulative CO₂ assimilation per unit leaf N duration but slightly positively correlated with leaf N-use efficiency expressed per unit of average leaf N content. Shoot architecture had little impact on these variables and relationships. We conclude that leaf longevity is an important factor in leaf N-use efficiency but that genetic variation for shoot architecture in common bean is not important in determining the N-use efficiency of individual leaves.

Received for publication November 2, 1993.

This article has been cited by other articles:

				K. L. Nielsen, A. Eshel, and J. P. Lynch The effect of phosphorus availability on the carbon economy of contrasting common bean (Phaseolus vulgaris L.) genotypes J. Exp. Bot., February 1, 2001; 52(355): 329 - 339. [Abstract] [Full Text] [PDF]