Pigeonpea cyst nematode - Heterodera cajani
Effective: August 18, 2010
Tylenchida : Heteroderidae
Pest Code (NAPIS):
This pest is a member of the following lists:
These Approved Methods are appropriate for:
2020, 2019, 2018, 2017, 2016, 2015
Pest is vectored by:
This pest is is not known to be a vector and it is not vectored by any organism.
|| NAPIS Survey Method
| Soil Sample
|| Send sample to nematology diagnostic lab where nematodes will be extracted and identified (preferred method)
3012 - General Soil Sample
| Tissue Sample
|| Send sample to nematology diagnostic lab where nematodes will be extracted and identified.
3011 - General Tissue Sample
Survey Instruction Details:
Laboratory methods that are acceptable for cyst extraction include sugar centrifugation, USDA cyst extractor, Fenwick can sieving, wet sieving, and elutriation.
The disease is recognized by the presence of pearly white, lemon-shaped females on roots or brown cysts in the soil.
A reduction in height and vigor of the infected plants can be discerned by careful comparison with healthy plants. Stunting, reduced leaf lamina size, and yellowing on cotyledonary leaves may or may not be readily visible. Flowers and pods are reduced in size and number, and the root system may also be poorly developed.
Morphological: Characteristics of second-stage juveniles, males, females, and cysts.
Mulvey (1972) provides a key to 39 species of Heterodera, including H. cajani, based on characteristics of cysts.
Sharma and Swarup (1983) provide morphological keys, based on cyst, cone top structures, and second-stage larvae, to cyst nematode species occurring in India, including H. cajani.
Heterodera cajani resembles species in the schachtii group, including H. trifolii, H. glycines, H. sacchari, H. schactii, H. mothi, H. galeopsidis, and H. lespedezae.
Characteristics of the second-stage juveniles, cyst size, and vulval cone characteristics are useful to separate H. cajani from H. trifolii, H. glycines, H. sacchari, H. schactii, and H. mothi. The presence of males and host range separate H. cajani from H. galeopsidis, and H. lespedezae, respectively.
In Progress / Literature-based Diagnostics:
Biochemical: Singh et. al. (1998) used the isozyme patterns of esterases and malate dehydrogenase to separate two races of H. cajani and three races of H. zeae.
Molecular: Heterodera species can be identified by sequencing the ITS-rRNA genes and by PCR-RFLP profiles; these tools remain the best available for identifying cyst-forming nematodes (Waeyenberge et al., 2009; Subbotin et al., 2010).
The wide host range among leguminous crops and the ability of this pest to become established in tropical and subtropical areas, makes this nematode a dangerous species.
This nematode can be introduced with legumes, plant debris, and soil contaminated with cysts.