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Photosynthesis, growth and nutrient changes in non‐nodulated Phaseolus vulgaris grown under atmospheric and elevated carbon dioxide conditions
Author(s) -
Mjwara Jabulani M.,
Botha C. Edward J.,
Radloff Sarah E.
Publication year - 1996
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1996.tb00541.x
Subject(s) - phaseolus , photosynthesis , chlorosis , carbon dioxide , nutrient , relative growth rate , horticulture , chemistry , dry weight , zoology , botany , growth rate , biology , geometry , mathematics , organic chemistry
The response of Phaseolus vulgaris L. cv. Contender grown under controlled environment at either ambient or elevated (360 and 700 μmol mol ‐1 , respectively) CO 2 concentrations ([CO 2 ]), was monitored from 10 days after germination (DAG) until the onset of senescence. Elevated CO 2 had a pronounced effect on total plant height (TPH), leaf area (LA), leaf dry weight (LD), total plant biomass (TB) accumulation and specific leaf area (SLA). All of these were significantly increased under elevated carbon dioxide with the exception of SLA which was significantly reduced. Other than high initial growth rates in CO 2 ‐enriched plants, relative growth rates remained relatively unchanged throughout the growth period. While the trends in growth parameters were clearly different between [CO 2 ], some physiological processes were largely transient, in particular, net assimilation rate (NAR) and foliar nutrient concentrations of N, Mg and Cu. CO 2 enrichment significantly increased NAR, but from 20 DAG, a steady decline to almost similar levels to those measured in plants grown under ambient CO 2 occurred. A similar trend was observed for leaf N content where the loss of leaf nitrogen in CO 2 ‐enriched plants after 20 DAG, was significantly greater than that observed for ambient‐CO 2 plants. Under enhanced CO 2 , the foliar concentrations of K and Mn were increased significantly whilst P, Ca, Fe and Zn were reduced significantly. Changes in Mg and Cu concentrations were insignificant. In addition. high CO 2 grown plants exhibited a pronounced leaf discoloration or chlorosis, coupled with a significant reduction in leaf longevity.