PARENT SESSION
Poster Session 39: Late Breaking and Newsworthy Posters
Friday, August 12, 8:30 AM - 10:30 AM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal

Young Daughter Cladodes Affect CO2 Uptake by Mature Cladodes of Opuntia ficus-indica.

Pimienta-Barrios, Eulogio^*,1, Zañudo-Hernàndez ., Julia ², Nobel , Park S³, ¹ UNIVERSIDAD DE GUADALAJARA, UNIVERSIDAD DE CALIFORODAniveru, JALISCO, MEXICO² UNIVERSIDAD DE GUADALAJARA, ZAPOPAN, JALISCO, MEXICO³ UNIVERSITY OF CALIFORNIA LOS ANGELES, LOS ANGELES, CALIFORNIA, USA

ABSTRACT- The effects of the number of daughter cladodes on gas exchange parameters were evaluated for underlying basal cladodes of Opuntia ficus-indica exposed to varying soil water contents. Daily carbon gain by basal cladodes was reduced as the number of daughter cladodes was increased up to eight, especially during drought. The reduction was accompanied by lower relative water content, suggesting a movement of water from underlying cladodes to daughter cladodes. CO2 assimilation was most affected in phase IV (late afternoon net CO2 uptake) by the combined effects of daughter cladodes and drought. Natural rainfall raised the soil water content, eliminating most of the effects of daughter cladodes on net CO2 uptake by the underlying cladodes.

Key words: CRASSCULACEN ACID METABOLISM, CACTUS, DROUGHT, GAS EXCHANGE