Investigating Genetic Diversity and Correlations Between Mineral Concentration and Neurotoxin (β-ODAP) Content in the Lathyrus Genus

Abstract

Grass pea (<i>Lathyrus sativus</i> L.) is a nutritious legume crop well-adapted to fragile agro-ecosystems that can survive under challenging climatic conditions. The cultivation of grass pea faces stigma primarily due to the presence of <i>β</i>-<i>N</i>-Oxalyl-<i>L</i>-<i>α</i>, <i>β</i>-diaminopropionic acid (<i>β</i>-ODAP), which is associated with a risk of inducing neurolathyrism upon prolonged consumption of its grains as a staple diet. The grass pea improvement program of the International Center for Agricultural Research in the Dry Areas (ICARDA) aims to reduce <i>β</i>-ODAP content to a safe level along with improving yield potential and nutritional quality of grass pea. In this study, 183 germplasm accessions representing 13 different <i>Lathyrus</i> species and 11 <i>L. sativus</i> breeding lines were evaluated for <i>β</i>-ODAP content based on Rao protocol and mineral concentration using ICP-OES. Significant variability was observed among the accessions for the studied traits. The results showed low <i>β</i>-ODAP content and high mineral concentration in 25 accessions of crop wild relatives, which included <i>L. cicera</i>, <i>L. ochrus</i>, and <i>L. cassius</i>, with one accession IG65277 of <i>L. cassius</i>, in addition to two lines, IG117034 and ACC1335, of <i>L. sativus</i> having very low <i>β</i>-ODAP content. Furthermore, some accessions of <i>L. pseudocicera</i>, <i>L. aphaca</i>, <i>L. cicera</i>, <i>L. marmoratus</i>, <i>L. gorgoni</i>, and <i>L. tingitanus</i> also showed low <i>β</i>-ODAP content. The results showed significant positive correlations among different trait combinations, viz., K and P (r = 0.193 ***), K and Fe (r = 0.177 ***), Mn and Fe (r = 0.210 ***), Mn and Se (r = 0.137 ***), <i>β</i>-ODAP and Mg (r = 0.158 **), and <i>β</i>-ODAP and Ca (r = 0.140 **). <i>L. cicera</i>, <i>L. ochrus</i>, and <i>L. cassius</i> were identified as a great source for improving the mineral concentration and reducing <i>β</i>-ODAP content in the cultivated grass pea.