Mycorrhizal fungi enhance growth and nutrient uptake of prickly-pear cactus (Opuntia albicarpa Scheinvar 'Reyna') plantlets after ex vitro transplantation
Aa. Estrada-luna et Ft. Davies, Mycorrhizal fungi enhance growth and nutrient uptake of prickly-pear cactus (Opuntia albicarpa Scheinvar 'Reyna') plantlets after ex vitro transplantation, J HORT SCI, 76(6), 2001, pp. 739-745
We studied the effects of a mixed Mexican arbuscular mycorrhizal (AM) funga
l inoculum (composed of Glomus albidum, G. diaphanum, and G. claroides) and
low phosphate supply (0 and 11 mug P ml(-1)) on growth and nutrient uptake
of micropropagated prickly-pear cactus (Opuntia albicarpa Scheinvar Reyna)
plantlets. After seven months of glasshouse culture, there was 100% surviv
al of the micropropagated plantlets. Mycorrhizal colonization occurred rapi
dly within 5 d of inoculation, with the development of internal hyphae in r
oot cortical cells. At the end of the study, high levels (48-54%) of coloni
zation were observed. Plantlets transferred to soil began to grow actively
with no lag phase. However, plant growth rate was significantly affected by
treatments. Poorest growth occurred with uninoculated plantlets that lacke
d supplementary P supply. In contrast, the combination of mycorrhizal colon
ization and supplementary P significantly increased shoot length, shoot and
root DM and surface area of the plantlets. AM fungi enhanced concentration
of P and Zn and increased nutrient uptake of P, B and Zn in the cladodes.
We conclude that AM fungi can be used as a biotechnological tool that allow
s more efficient, low P input to enhance ex vitro transplantation of O. alb
icarpa.