Project Number: 5305-22000-012-07
Project Type: Trust

Start Date: Apr 01, 2005
End Date: Mar 31, 2009

Objective:
Evaluate and select progeny and breeding lines for resistance to Bacterial Leaf Spot (BLS) in greenhouse screenings. Evaluate and select progeny and breeding lines for resistance to BLS in field evaluations. Screen F2 and F3 families to determine the inheritance of BLS resistance in Little Gem and Batavia Reine des Glaces. Isolate and characterize Sphingomonas sp. from roots of several resistant cultivars grown in the putative cor-breaking soil (cBS). Complete Koch's postulates on strains related to Sphingomonas sp. isolated from the roots of resistant plants grown in cBS. Continue the development of molecular detection and quantification system for the corky root pathogen(s).

Approach:
Published screening methods will be used to evaluate resistance of progeny and breeding material to BLS (Bull et al., 2005). Resistant material will be propagated so that further evaluations or breeding can occur. Standard methods for completing Koch's postulates will be used for identification of organisms causing Corky Root disease on formerly resistant lettuce cultivars. Primers developed for detection will be tested to insure specificity and empirical experiments involving changes in reaction conditions will be conducted to improve sensitivity of detectiona dn quantification of the pathogen(s). Documents Trust with CA Lettuce Bd. Log 28894.