Comment from Richard Gaskalla

The FDACS-DPI carefully reviewed and evaluated the interim rule (Docket No. APHIS-2008-0052) regarding citrus seed imports: citrus greening and citrus variegated chlorosis (CVC). It was indicated within the interim rule that there existed emerging scientific evidence suggesting that seed intended for propagation of genera that are hosts for citrus greening can transmit the disease. There is ongoing research exploring the likelihood of propagative seed transmission of the Canidatus Liberibacter species associated with citrus and citrus relatives. To date, there has been no conclusive evidence to indicate that citrus greening can be seed-transmitted in Citrus. On the contrary, published research (Albrecht and Bowman 2009; Shokrollah et al. 2009) actually suggests that citrus greening is not seed borne. Without firm scientific data to support the seed borne transmission of citrus greening, FDACS-DPI does not favor its inclusion into the rule. We acknowledge that only long-term studies can answer this question of seed transmission of HLB with more precision and confidence. This agency is supportive of the USDA-APHIS recommendation to prohibit the importation of propagative seed from several Rutaceae genera from certain countries where citrus variegated chlorosis (CVC) is known to occur. We are further supportive of requiring propagative seed of these genera imported from all other countries to be accompanied by a phytosanitary certificate with an additional declaration that CVC is not present within these countries. Literature cited: Albrect, Ute and Kim D. Bowman. 2009. Canidatus Liberibacter asiaticus and Huanglongbing Effects on Citrus Seeds and Seedlings. HortScience 44: 1967-1973. Shokrollah, Hajivand, Thohirah Lee Abdullah, Kamaruzaman Sijam and Siti Nor. 2009. Determination of the Presence of Huanglongbing in Seeds and Movement of the Pathogen in Citrus reticulata. American Journal of Applied Sciences 6 :60: 1180-1185.