Grass pea or chickling vetch ( Lathyrus sativus L.) is a herbaceous plant, a diploid species. belonging to the Fabaceae family and is also the most widely cultivated species of Lathyrus for food and feed purposes. It is also called guinea pea and grass pea. The genus Lathyrus comprises about 180 species and is mainly found in temperate regions of the northern hemisphere, South America, southern Asia and sub-Saharan Africa. The best-known species are:

• Lathyrus sativus L.
• Lathyrus cicera L.
• Lathyrus odoratus L. 

It is a hardy and versatile crop with excellent tolerance to abiotic stresses, excellent adaptability to difficult climatic conditions such as drought, flooding, intense cold, excessive heat, resistance to salt and to many pests. In particular, salinity is the greatest danger to cultivated plants and is one of the main causes of soil degradation worldwide.

The cultivation of chickling vetch, which has long been used as a cooked, fermented or roasted foodstuff, particularly in past generations, has declined dramatically in recent years following the discovery of a neurotoxin, β-N-oxalyl-L-α, β-diaminopropionic acid (β-ODAP), present in both the plant and the seeds. This toxin, which appears to be linked to sulphur metabolism, is responsible for a serious and non-reversible neurological disorder in humans and animals, neurolathyrism, a degenerative motor neuron syndrome, leading to convulsions and paralysis of the lower limbs, spastic paraparesis. The toxin occurs in alpha and beta isomeric forms with a β-isomer content of up to 95 % of the total ODAP (1).  The seeds can be partially detoxified by fermentation, cooking or soaking in alkaline solutions (2). Many countries have banned the cultivation of this legume. To counteract its toxicity, India has produced some low-toxin varieties of Lathyrus sativus (Ratan, Prateek, Mahateora) with an ODAP content of less than 0.10 % (3).

With regard to the phytochemical composition, chickling vetch has a high content of proteins, flavonoids and the presence of iron (41-43 ppm), zinc (19-54 ppm) is observed. Carbohydrates account for 51-73% and starch for 35-52%. Saturated fatty acids 16-54% and unsaturated fatty acids 45.7-66.7%. We find potassium in 8.33-11.05 ppm, manganese in 7.86-42.5 ppm and a small amount of magnesium, 0.86-1.61 ppm (4).

Secondary genetic pool (Heywood et al., 2007):

• L. cicera   
• L. amphicarpus
• L. crisante
• L. gorgoni
• L. marmoratus
• L. pseudocicera
• L. blepharicarpus
• L. choranthus
• L. ierosimitano
• L. hirsutus

Chickling vetch has proved very useful in remediating and restoring the quality and fertility of soils polluted by heavy metals such as Lead and Cadmium (5).

Chickling vetch and toxins, studies

References_______________________________________________________________________

(1) De Bruyn, A., Becu, C., Lambein, F., Kebede, N., Abegaz, B., & Nunn, P. B. (1994). The mechanism of the rearrangement of the neurotoxin β-ODAP to α-ODAP. Phytochemistry, 36(1), 85-89.

(2) Getahun H, Lambein F, Vanhoorne M. Neurolathyrism in Ethiopia: assessment and comparison of knowledge and attitude of health workers and rural inhabitants. Soc Sci Med. 2002 May;54(10):1513-24. doi: 10.1016/s0277-9536(01)00131-9.

(3) Kumar, S., Bejiga, G., Ahmed, S., Nakkoul, H., & Sarker, A. (2011). Genetic improvement of grass pea for low neurotoxin (β-ODAP) content. Food and Chemical Toxicology, 49(3), 589-600.

(4) Das A, Parihar AK, Barpete S, Kumar S, Gupta S. Current Perspectives on Reducing the β-ODAP Content and Improving Potential Agronomic Traits in Grass Pea (Lathyrus sativus L.). Front Plant Sci. 2021 Oct 18;12:703275. doi: 10.3389/fpls.2021.703275.

(5) Abdelkrim S, Jebara SH, Saadani O, Abid G, Taamalli W, Zemni H, Mannai K, Louati F, Jebara M. In situ effects of Lathyrus sativus- PGPR to remediate and restore quality and fertility of Pb and Cd polluted soils. Ecotoxicol Environ Saf. 2020 Apr 1;192:110260. doi: 10.1016/j.ecoenv.2020.110260.