Brote Grande, A New Phytoplasma Associated Disease of Chile Peppers in the Desert Southwest

Abstract

Chile is one of the most important crops in New Mexico, contributing both to the agricultural economy and cultural identity of the state. Diseases are a major constraint on chile production in New Mexico and across the Desert Southwest. Chile producers in New Mexico recently reported a disorder of unknown etiology that was observed in increasing frequency for the past four years. Affected plants have a bushy appearance, develop overly large green calyces instead of normal flowers, and fail to set fruit. This characteristic phyllody has led the disorder to be referred to as “brote grande” which is Spanish for “big bud.” The phyllody is reminiscent of the aberrant flower development associated with tomato big bud, a phytoplasma disease of tomatoes. Microscopic analysis, including light microscopy and TEM along with PCR detection using phytoplasma specific primer sets, indicates that brote grande disease is associated with a novel phytoplasma. Field surveys conducted in 2008 and 2009 indicate that this new disease is widely distributed at low levels across chile production areas in New Mexico and Arizona. Accepted for publication 10 January 2011. Published 1 March 2011.