Glossary

Term

Definition

Area-wide pest management

A coordinated application of insecticides or some other control tactic on a large scale, beyond individual properties, with the goal of suppressing a pest population.

Asian citrus psyllid (ACP)

Asian citrus psyllid, Diaphorina citri, is a sap-sucking insect that is an important pest of citrus and the only species that can transmit Candidatus Liberibacter asiaticus, the bacterium that causes huanglongbing.

Biological control

Intentional use by humans of natural enemies, predators, parasitoids, and pathogens to reduce pest populations to less damaging levels (from Hoddle Snapshot).

Candidatus Liberibacter asiaticus (CLas)

Pathogenic bacterial agent, causing Huanglongbing disease (HLB).

Citrus tristeza virus (CTV)

A plant virus of the family Closteroviridae that infects plants in the genus Citrus. It causes a disease called citrus tristeza, which is considered one of the most severe diseases of citrus trees

CRISPR

CRISPR-Cas: clustered regularly interspaced short palindromic repeats– CRISPR-associated protein

Disease management

Various tactics that could be used to mitigate the impact of HLB on established orchards

Early Detection Technologies (EDT)

Tests that indicate that a tree is infected before symptoms of the disease can be seen, or before the pathogen DNA can be detected through PCR

Gene editing

Involves manipulating genetic material (DNA) of organism by deleting, replacing, or inserting a DNA sequence in a specific location in the genome

Huanglongbing (HLB)

Devastating bacterial disease of citrus (yellow shoot disease).  Currently incurable, it is spread by grafting or by the ACP vector.

Marker-Assisted Selection (MAS)

Procedure used in plant breeding in which genetic markers that are easy to identify and linked to desirable genetic traits are used to aid in selecting individual plants from a population

Metabolites

Proteins and small molecular weight chemicals. These molecules change in abundance when the metabolism of a living organism is altered (from Slupsky Snapshot).

Microbiome

Community of microorganisms (bacteria, fungi, and/or viruses) living in a particular ecological niche, such as the root system of citrus trees, or the human body

Peptides

Small proteins composed of a few (2-15) aminoacids (mentioned in Dawson and Pelz-Stelinski, and Shatters Snapshots).

Petiole

Slender stalk that joins the leaf lammina to the stem

Phloem

Plant vascular tissue that transports sugars synthesized through photosynthesis from the leaves to the rest of the plant

Phytophthora

Genus of Oomycete (fungal-like) pathogens (mentioned in Gottwald and Hoddle Snapshots).

Polymerase Chain Reaction (PCR)

A technique used to amplify the number of copies in a specific region of DNA in order to produce enough of the DNA for use in various applications, such as detection of a pathogen in plant tissue

Poncirus trifoliata

Member of the citrus family (mentioned in Hall and Stover Snapshots).

Psyllid management

Methods that could be used to alter or affect the psyllid so that it can not spread the bacterium that causes HLB.

Rootstock

Trunk and root system of a citrus tree into which a scion is grafted

Scion

Fruit producing part of a citrus tree, which is grafted onto the rootstock

Tamarixia radiata

Tiny wasp that lays its eggs on Asian citrus psyllid (ACP) nymphs. When eggs hatch, larvae feed on ACP nymphs, ultimately leading to their death.

Vector

Organism able to carry and transmit a pathogen between hosts. In the case of HLB, the Asian Citrus Psyllid is the vector that transmits the pathogen Candidatus Liberibacter asiaticus between citrus hosts

Volatile organic compounds (VOCs)

Products of plant metabolism that are gases and emit an odor (from Davis Snapshot).