COMMERCIALIZING PRODUCTS FROM PLANT BIOTECHNOLOGY 195

zae is a beneficial root fungus that is associated with nearly all plant roots
(Gerdemann, 1975). This root symbiont grows into the cortex of a root
where it produces structures termed arbuscules and vesicles within the root
cells (Figure 1). External to the root, the hyphae proliferate into the soil in
considerable abundance and serve as a conduit for uptake of water and
plant nutrients as well as form a protective screen against many plant
pathogens in the soil (Menge, 1980). One of the first practical applications
suggested for mycorrhizae was to inoculate seedlings to assist in their es-
tablishment upon being transplanted into sterile soils following massive
disturbance from surface mining and in revegetating spent oil shale dis-
posal sites (Aldon, 1978; Call and McKell, 1985). Concurrently, Professor
Menge at the University of California, Riverside, demonstrated the use of
inoculants on citrus transplants and other horticultural crops to increase
their establishment success.



 CASPARIAN
 HYPHAE, V STRIP

 r \ C CORTICAL STELLAR










 ARBUSCULES ENDODERMAL
 CELLS
 EPIDERMAL CELLS
 CELLS



 TYPICAL VESICULAR-ARBUSCULAR MYCORRHIZA
 Figure 1. Cross-section of a root showing the relation of mycorrhizal
structures in the cortex and external area of the root. The greater extent of
hyphae compared with root hairs assist in the uptake of nutrients and
water.