Wheat yield progress associated with higher stomatal conductance and photosynthetic rate, and cooler canopies

• Published in: Crop science Vol. 38; no. 6; pp. 1467 - 1475
• Main Authors: Fischer, R.A. (ACIAR, Canberra, Australia.), Rees, D, Sayre, K.D, Lu, Z.M, Condon, A.G, Saavedra, A.L
• Format: Journal Article
• Language: English
• Published: Madison, WI Crop Science Society of America 01-11-1998; American Society of Agronomy
• Subjects: Agronomy. Soil science and plant productions; AIR TEMPERATURE; Anatomy; Biological and medical sciences; Botany; CANOPY; CARBON DIOXIDE; COLOR; COLOUR; CONDUITE DE LA CULTURE; CONTENIDO DE NITROGENO; COULEUR; COUVERT; CRITERE DE SELECTION; CRITERIOS DE SELECCION; CROP MANAGEMENT; CROP YIELD; Crops; CUBIERTA DE COPAS; CULTIVARS; DIOXIDO DE CARBONO; DIOXYDE DE CARBONE; ECHANGE GAZEUX; FEUILLE; FISIOLOGIA VEGETAL; FLORACION; FLORAISON; FLOWERING; FOTOSINTESIS; Fundamental and applied biological sciences. Psychology; GAS EXCHANGE; Genetics and breeding of economic plants; GROWTH RATE; Harvesting; HOJAS; INDICE DE CRECIMIENTO; INTERCAMBIO DE GASES; LEAF AREA; LEAVES; MANEJO DEL CULTIVO; MEXICO; MEXIQUE; NITROGEN CONTENT; PESO; PHOTOSYNTHESE; PHOTOSYNTHESIS; PHYSIOLOGIE VEGETALE; Plant canopies; PLANT PHYSIOLOGY; POIDS; RENDEMENT DES CULTURES; RENDIMIENTO DE CULTIVOS; SELECTION CRITERIA; Spring wheat; Stomatal conductance; SUPERFICIE FOLIAR; SURFACE FOLIAIRE; TAUX DE CROISSANCE; TEMPERATURA DEL AIRE; TEMPERATURE DE L'AIR; TENEUR EN AZOTE; TRITICUM AESTIVUM; VARIEDADES; Varietal selection. Specialized plant breeding, plant breeding aims; VARIETE; VARIETIES; WEIGHT; Wheat; Yield, quality, earliness, varia; Agronomic character; Monocotyledones; Temperature; Carbon isotope discrimination; Stomatal conductance; Cereal crop; Gramineae; Angiospermae; Genetic improvement; Selection criterion; Ratio; Spermatophyta; Yield component; Photosynthesis; Triticum aestivum; Canopy(vegetation)
• ISSN: 0011-183X; 1435-0653
• DOI: 10.2135/cropsci1998.0011183X003800060011x

Grain yields of eight representative semidwarf spring wheat (Triticum aestivum L.) cultivars released in northwest Mexico between 1962 and 1988 have increased linearly across years as measured in this region during 6 yr under favorable management and irrigation. To understand the physiological basis of this progress and possibly assist future selection for grain yield, leaf traits were determined during 3 yr in the same study. Stomatal conductance (g(S)), maximum photosynthetic rate (A(max)), and canopy temperature depression (CTD), averaged over the 3 yr, were closely and positively correlated with progress in the 6-yr mean yield. The correlation was greatest with g(S) (r = 0.94 P 0.01). Compared with the overall yield increase of 27%, g(S) increased 63%, A(max) increased 23%, and canopies were 0.6 degree C cooler. Carbon-13 isotope discrimination was also positively associated with yield progress (r