- Identity: Known by various names including its scientific name Anguina tritici, and has EPPO codes ANGUTR and RHATTR. It has different common names in multiple languages and regions.
- Distribution: Once widespread, now becoming rarer in some areas. Present in Africa (e.g., Egypt, Ethiopia), Asia (e.g., China, India, Iran), Europe (e.g., Austria, France, Germany), Oceania (Australia, New Zealand), and was formerly in South America (Brazil). Absent in some US states where it was previously present.
- Growth Stages:Seedling: Causes leaf symptoms such as wrinkling, twisting, and dwarfing.Heading: Reduces wheat heads with abnormal glume angles, exposing galls (not in rye heads).Galls: Young galls are short-thick, green to brown-black. Rye galls are smaller and buff-colored.
- Seed Quality: Leads to significant losses. Completely infected ears have 100% grain loss. Partially affected ears also have substantial losses in number and weight, and the grain quality is inferior.
- Transmission: Mainly through infected wheat seeds and planting infected galls. In India, a significant portion of wheat samples were contaminated.
- Takes weeks for galls to release juveniles in moist soil. Juveniles reach a plant in 2 - 9 days and migrate to the growing point. They invade floral tissues, form galls, and develop into males or females. The life cycle is about 113 days but can be up to 164 days in India. Juveniles can overwinter in different ways and survive for a long time in certain conditions, e.g., 35 years in dry storage but not more than 1 year in field soil.
- Through direct visual inspection, wash-filter, freezing-blotter, embryo, and specific tests. Also via methods like dissection, salt assay, and Baermann funnel method. It needs to be distinguished from similar symptoms and other species using techniques like PCR-RFLP and real-time PCR.
- Cultural and Sanitary:Seed cleaning: Use salt brine method to separate galls and then treat them.Crop rotation or fallow: If soil is left fallow or planted with non-host crops, the nematode can be eliminated in over a year.
- Physical: Hot-water treatments at specific temperatures and durations can eradicate the nematode from seeds. Mechanical separation with specialized machines is also effective.
- Biological: Few reports exist, but some nematodes and fungi can reduce its numbers.
- Host-Plant Resistance: Some resistant plants have been found, but it's not a comprehensive solution.
The wheat seed gall nematode poses a significant threat to wheat production. Understanding its characteristics, impact, and control methods is crucial for effective management to ensure the health of wheat crops and the stability of agricultural production. By implementing a combination of these control strategies, we can better combat this pest and safeguard the quality and quantity of wheat yields.
