Influence of phosphorus and endomycorrhiza (Glomus intraradices) on gas exchange and plant growth of chile ancho pepper (Capsicum annuum L. cv. San Luis)
L. Aguilera-gomez et al., Influence of phosphorus and endomycorrhiza (Glomus intraradices) on gas exchange and plant growth of chile ancho pepper (Capsicum annuum L. cv. San Luis), PHOTOSYNTHE, 36(3), 1999, pp. 441-449
Seedlings of chile ancho pepper were grown in pots containing a pasteurized
mixture of sand and a low phosphorus (P) sandy loam soil, and either inocu
lated (VAM) or not inoculated (NVAM) with the endomycorrhizal fungus Glomus
intraradices. Long Ashton nutrient solution (LANS) was modified to supply
P to the seedlings at 0, 11, and 44 g(P) m(-3) (P-0, P-11, P-44, respective
ly). Low P depressed net photosynthetic rate (P-N), stomatal conductance (g
(s)), phosphorus use efficiency (P-N/P), and internal CO2 concentration (C-
i). The mycorrhiza alleviated low P effects by increasing P-N g(s), P-N/P,
and decreasing C-i. At P-0, C-i of NVAM plants was equal to or higher than
that of VAM plants, suggesting nonstomatal inhibition of photosynthesis. Ga
s exchange of VAM plants at P-0 was similar to that of NVAM plants at P-11.
Endomycorrhiza increased leaf number, leaf area, shoot, root and fruit mas
s at P-0 and P-11 compared to NVAM plants. Reproductive growth was enhanced
by 450% in mycorrhizal plants at P-44 Root colonization (arbuscules, vesic
les, internal and extraradical hyphae development) was higher at lower P co
ncentrations, while sporulation was unaffected. The enhanced growth and gas
exchange of mycorrhizal plants was in part due to greater uptake of P and
greater extraradical hyphae development.