Envirologix: Putting Science to the Test

Bacterial Fruit Blotch

Bacterial Fruit Blotch (BFB)

Bacterial fruit blotch (BFB), caused by Acidovorax avenae subsp. citrulli (Aac), was first recognized as a disease of watermelons in Florida in 1989. Since then, outbreaks of BFB have been reported every year and the host range has expanded to other cucurbit species. BFB can be introduced in production fields by infected transplants (derived from contaminated seed), and to some extent by volunteer host plants found in the fields.

Contaminated seed represents the most important means of disease transmission. Hot and humid environmental conditions found in transplant houses contribute further to the fast spread of this disease. One single infected seed or transplant could contaminate entire sections of a transplant house; therefore, it is recommended that transplant growers inspect seedlings on a routine basis, especially before releasing them to commercial fields. Seedling flats with suspected symptoms of BFB must be destroyed.

The QuickStix Kit for Bacterial Fruit Blotch, utilizing a monoclonal antibody, offers the specificity, sensitivity and convenience necessary to assist plant raisers in making on-site diagnosis for this devastating disease.

Because one single infected seed could contaminate entire sections of a transplant house, zero tolerance for seed contamination is essential to control this disease. The seedling grow out is the current accepted method by the seed industry to detect BFB on commercial seed lots. Unfortunately, it is a lengthy process and can be costly. More recently, PCR-based assays have been developed, but they require expensive and time-consuming DNA preparations.

Our newest product, the QuickBead™ Kit for Bacterial Fruit Blotch, is the first commercial kit of prepared immunomagnetic beads (IMBs) to be used for the detection of BFB on seed washes. The beads are coated with antibodies specific to Acidovorax avenae subs. citrulli (Aac), the causal agent of BFB. Our IMBs allow sensitive and specific capture of Aac from seed wash extracts, expediting clean downstream analysis of the bacteria.

The coated QuickBeads trap the Aac bacteria on the surface of the beads. Exposing them to a magnetic field allows the separation of the beads (along with the bacteria) from unwanted material, thus yielding a clean and concentrated sample of the organism. This technique is known as Immuno-Magnetic Separation (IMS).

IMS combined with PCR (IMS-PCR) is a valuable technique for the detection of Bacterial Fruit Blotch in seed washes. The use of IMBs for IMS-PCR-based detection of BFB has been characterized and documented by Dr. Ron Walcott, Associate Professor of Plant Pathology at the University of Georgia.

Now testing labs can have highly sensitive and well characterized antibody-coated magnetic beads for IMS-PCR analysis at a fraction of the cost of coating their own. This is also a practical alternative to the more costly and time-consuming seedling grow out.

Click here for detailed information on the QuickStix Kit for Bacterial Fruit Blotch

Click here for detailed information on the QuickBead Kit for Bacterial Fruit Blotch

Click here for detailed information on our other Plant Pathogen Test Kits

Sources: Florida Department Of Agriculture & Consumer Services, Division of Plant Industry; “BFB-A Commercial Grower’s Guide” pamphlet; “Guidelines for Managing Bacterial Fruit Blotch Disease” – UGA/UF/Purdue University

PDF files, where provided, require Adobe Acrobat Reader.

- up -