Wheat seed gall nematode

The wheat seed gall nematode (Anguina tritici) is a specialized plant-parasitic nematode belonging to the family Anguinidae. It is a classic example of a seed-borne pathogen that causes a disease historically known as "ear cockle" of wheat. Unlike many other nematodes that attack roots, this species is specialized to invade the aerial parts of cereal plants, particularly the developing grains.

The primary hosts for Anguina tritici include wheat (both bread and durum) and rye. The infection leads to the transformation of healthy kernels into dark, hard galls, often referred to as "cockles." Symptoms on infected plants include stunted growth, leaf twisting, and distorted, bushy ears. These structural changes severely weaken the plant and significantly reduce grain yield.

The life cycle of this nematode is perfectly synchronized with the development of the host plant. Juvenile larvae emerge from the galls in the soil or in the seed lot under favorable moisture conditions. They climb the stem of the host, penetrate the immature tissues, and reach the floral primordia. Once inside, they transform into adult worms, mate, and produce a new generation of larvae that encyst within the developing galls.

The spread and development of the pathogen are highly dependent on moisture. Wet conditions in the early stages of plant growth facilitate the movement of larvae from the soil to the crown of the plant. The larvae are incredibly resilient; when inside the dried galls, they can survive for several years in the soil or in stored grain, effectively bridging gaps between growing seasons.

Economic impact is significant, as it leads to both quantitative losses and the contamination of harvested grain with nematode galls, making it unsuitable for processing. Management of Anguina tritici relies on preventative agricultural practices:

• Use of certified, nematode-free seed lots.
• Physical removal of galls using gravity separators or brine flotation methods.
• Crop rotation, avoiding host crops for at least two to three years.
• Destruction of crop residues through deep tillage to bury the galls.