HOST DETERMINANTS OF MYCORRHIZAL DEPENDENCY OF CITRUS ROOTSTOCK SEEDLINGS

Open Access
Publisher Website
Google Scholar
Abstract
Summary: Seedlings of five citrus rootstocks were grown in a low phosphorus (P) sandy soil and were either (1) inoculated with Glomus intraradices Schenck & Smith, (2) non‐inoculated and fertilized with P, or (3) non‐inoculated without added P. The order of mycorrhizal dependency (MD) of the five rootstocks was sour orange = Cleopatra mandarin > Swingle citrumelo > Carrizo citrange > trifoliate orange. The less dependent rootstocks, trifoliate orange and its hybrid Carrizo citrange, had greater leaf P, finer roots (greater length per unit of dry root) and slower growth rates than sour orange and Cleopatra mandarin. Rootstocks with lower MD also generally had greater hydraulic conductivity of roots, and greater transpiration and CO2 assimilation rates. Under well‐watered conditions, VAM plants of all five rootstocks did not differ in morphology, anatomy or physiology from non‐mycorrhizal plants fertilized with P of similar size, growth rate and P status.