Author
Submitted to: HortScience
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 6/6/2003 Publication Date: 10/1/2004 Citation: Scagel, C.F. 2004. Soil pasteurization and inoculation with mycorrhizal fungi alters flower productin and corm composition of brodiaea laxa. Hortscience. 39(6):1432-1437. Interpretive Summary: Maximum productivity and quality of bulb (corm) crops used for both flower and corm production requires a balance between resources allocated to flowering and corm production. The symbiotic relationship between vesicular-arbuscular mycorrhizal fungi (VAMF) and their plant symbiont can alter aspects of resource partitioning and metabolism that differentially influence productivity and quality of corm crops. Inoculation of Brodiaea laxa 'Queen Fabiola' can decrease the time until flower opening and plants generally lasted longer. Incoluation can also increase daughter corm size and production of cormels, but inoculated plants preferentially allocated more resources to daughter corms over cormels resulting in a lower average weight per cormel than in non-inoculated plants. Our results indicate that adding VAMF inoculum into the growing medium of B. laxa alters aspects of flowering and biomasses partitioning that are important in the commercial production of this crop for cut flowers and corms. Technical Abstract: Inoculum of the vesicular-arbuscular mycorrhizal fungus (VAMF) Glomus intraradices was added to pasteurized or non-pasteurized growing medium for Brodiaea laxa 'Queen Fabiola' to assess whether inoculation altered aspects of flower and corm production during two growing seasons after inoculation. Responses to inoculation were dependent on pasteurization of growing media. In general, VAMF decreased the number of days until flower opening, increased the number of flowers per inflorescence and flower longevity. Inoculation also altered aspects of daughter corm quality that influenced flowering in the year following inoculation. Inoculated plants had larger daughter corms and produced more cormels than non-inoculated plants but inoculation also preferentially increased biomass partitioning to daughter corms over cormels resulting in a lower average weight per cormel. Inoculation increased concentrations and content of potassium (K), nitrogen (N), zinc (Zn), and non-reducing sugars in daughter corms. Adding VAMF inoculum into the growing medium of B. laxa altered flowering during the first growing season after inoculation and some effects of VAMF inoculation were more pronounced in the second growing season after inoculation. Changes in biomass partitioning between corms and cormels in response to VAMF inoculation may be important in determining factors that influence the multiplication rate of this crop. |