Canopy gas exchange response to moisture stress in old and new maize hybrid

• Published in: Crop science Vol. 37; no. 1; pp. 172 - 181
• Main Authors: Nissanka, S.P. (University of Peradeniya, Peradeniya, Sri Lanka.), Dixon, M.A, Tollenaar, M
• Format: Journal Article
• Language: English
• Published: Madison, WI Crop Science Society of America 01-01-1997; American Society of Agronomy
• Subjects: Agricultural production; Agronomy. Soil science and plant productions; Biological and medical sciences; Botany; Corn; Cultivars: description, identification, tests, catalogs; DEFICIT DE HUMEDAD EN EL SUELO; DEFICIT HYDRIQUE DU SOL; DESHIDRATACION; DESHYDRATATION; Economic plant physiology; EFFICACITE; EFICACIA; ESTRES DE SEQUIA; Fundamental and applied biological sciences. Psychology; Gas exchange; Gases; Genetics and breeding of economic plants; GENOTIPOS; GENOTYPE; HIBRIDOS; Hybrid corn; HYBRIDE; Hybrids; INDICE DE SUPERFICIE FOLIAR; INDICE DE SURFACE FOLIAIRE; Moisture stress; ONTARIO; Physiological aspects; POTENTIEL HYDRIQUE; REHIDRATACION; REHYDRATATION; RESISTANCE A LA SECHERESSE; RESISTENCIA A LA SEQUIA; SECHERESSE; SEQUIA; STRESS DU A LA SECHERESSE; TENSION DE ABSORCION; TRANSPIRACION; TRANSPIRATION; USO DEL AGUA; UTILISATION DE L'EAU; Varietal selection. Specialized plant breeding, plant breeding aims; Water; Water relations, transpiration, stomata; XILEMA; XYLEME; ZEA MAYS; Canada; North America; Ontario; America; Short term; Hybrid variety; Monocotyledones; Water deficit; Environmental factor; Cereal crop; Resistance to injurious factors; Transpiration; New variety; Controlled environment study; Gramineae; Water regime; Angiospermae; Adaptation; Zea mays; Whole plant; Varietal selection; Ecophysiology; Genetic improvement; Spermatophyta; Yield; Gas exchange; Photosynthesis; Respiration; Cultivar
• ISSN: 0011-183X; 1435-0653
• DOI: 10.2135/cropsci1997.0011183x003700010030x

Grain yield improvement of maize (Zea mays L.) hybrids in Ontario has been associated with increased stress tolerance. Effects of short-term water-deficit stress on canopy gas exchange of an old and a new maize hybrid were studied. Plants of Pride 5 (old) and Pioneer 3902 (new) were grown under controlled-environment conditions until tassel emergence and, subsequently, plants were transferred to enclosures, each containing the aboveground parts of four plants. Canopy photosynthesis, respiration, transpiration, and stem water potential were measured continuously for 7 d. Plants were either well watered or exposed to a water-deficit stress by withholding water supply until net canopy photosynthesis declined to zero and, subsequently, plants were rehydrated. Under well-watered conditions, the two hybrids did not differ significantly in terms of canopy photosynthesis, transpiration, and stem water potential. In contrast, hybrids responded differently to a water-deficit stress. Cumulative canopy photosynthesis and transpiration during the drying cycle were reduced by 21 and 31%, respectively, in Pioneer 3902 and by 34 and 31%, respectively, in Pride 5. The threshold stem water potential related stomatal closure, and thus, photosynthesis and transpiration, was lower for Pioneer 3902 than for Pride 5. During the recovery day, canopy photosynthesis was 53% higher and canopy transpiration was 31% higher in Pioneer 3902 than in Pride 5. Respiration per unit CO2 fixed was lower in Pioneer 3902 than in Pride 5 in all conditions