CARBON-ISOTOPE DISCRIMINATION, WATER USE EFFICIENCY, NET PHOTOSYNTHESIS AND TRANSPIRATION IN MYCORRHIZAL KINNOW (CITRUS NOBILIS × C. DELICIOSA) PLANTS

In a field experiment, three-year-old Kinnow trees budded on Jatti Katti (Citrus jambhiri) rootstock were inoculated with three different arbuscular mycorrhizal fungus (AMF), Glomus manihotis (T₁), Glomus mosseae (T₂) and Gigaspora gigantea (T₃) separately or in combination (T₄). Plants were grown under an ordinary field management program with a non-limiting supply of water and fertilized with only farm yard manure.
Mycorrhizal infection increased transpiration rate by 46% with T₁ followed by T₄, T₃ and T₂ (30, 11 and 3%, respectively) over non-mycorrhizal plants.
Photosynthetic rate under saturated light condition increased 44% with T₄ followed by T₃ and T₁ (13 and 10%, respectively). Photosynthetic water use efficiency enhanced slightly as determined on the single leaf level (µmol CO₂/mol H₂O) or by carbon isotope discrimination (Δ¹³C). These data were also used to analyze correlation between Δ and water use efficiency (WUE) and some other plant attributes.
A strong positive correlation between Δ and WUE (r=0.622**) and between Δ and transpiration rate (r=0.697**) was observed.
WUE showed higher dependence on photosynthesis (r=0.578*) rather than transpiration rate (r=0.209).

XXVII International Horticultural Congress – IHC2006: International Symposium on Citrus and Other Tropical and Subtropical Fruit Crops

M.H. Shamshiri, K. Usha, B. Singh

respiration, Glomus manihotis, Glomus mosseae, Gigaspora gigantea

https://doi.org/10.17660/ActaHortic.2008.773.38