Lathyrus cicera x Lathyrus sativus interspecific hybrids: a way forward to quality and agronomic beneficial traits combination?

Grass pea (Lathyrus sativus) is a nutrient-rich, and “climate-resilient” grain legume neglected due to low yields and the presence of the neurotoxin β-ODAP. Its crop wild relative, Lathyrus cicera, shows lower ODAP contents, earliness, and better adaptation to low-rainfall. Through sexual crossing, hybrids-derived lines were successfully developed and selected based on fertility and adaptation, but not thoroughly evaluated until the present study. This study evaluated 14 of these L. cicera x L. sativus hybrid-derived lines, alongside four parental lines, over three seasons in Mediterranean environments, assessing a total of 19 diverse traits. Traits assessed included growth-, cycle duration-, yield-, seed type-, pest susceptibility-, and seed quality-related. Linear mixed models were applied to analyze diversity and Principal Component Analysis summarized hybrids similarities. Selection and backcrossing resulted in introgressed plants resembling L. sativus parents in flower and seed coat colour, but for some traits were different from these parents. The introgression of L. cicera phenotypes was observed in cycle duration-related traits, with several hybrid-derived lines earlier than L. sativus parents, but similar or later than L. cicera parents. Likewise, for the quality-related trait L-homoarginine seed content, one hybrid-derived line depicted higher content than any parent, suggesting transgressive segregation. Transgressive segregation was also detected for some seed type-related traits, with hybrid-derived lines depicting longer or flatter seeds than any parent. The introgression of beneficial alleles from L. cicera into L. sativus background seems a reliable approach to create variability and combine desirable quality and adaptive traits for grass pea improvement under Mediterranean conditions.