Adaptation of Grass Pea (Lathyrus sativus) to Mediterranean Environments

Abstract

Grass pea (Lathyrus sativus) is an annual legume crop widely cultivated in South Asia and Sub-Saharan Africa, but in regression in Mediterranean region. Its rusticity and nutritious value is calling back attention for its reintroduction into Mediterranean rain-fed farming systems. We studied the adaptation of a range of breeding lines in multi-environment field testing in Spain and Egypt, showing wide variation for grain yield. Broomrape (Orobanche crenata) infection appeared as the major limiting factor in both countries. Level of broomrape infection was highly influenced by environmental conditions, being favored by moderate temperatures at crop flowering and rain and humidity after flowering. The additive main effects and multiplicative interaction (AMMI) analysis was applied to understand the interaction between genotype (G) and environment (E) on grain yield and on broomrape infection. AMMI analyses revealed significant G and E effects as well as G*E interaction with respect to both traits. The AMMI analysis of variance (ANOVA) revealed that both, yield and broomrape infection were dominated by the environment main effect. AMMI1 biplot for grain yield revealed Ls10 and Ls11 as the accession with highest yields, closely followed by Ls16, Ls18 and Ls19. However, these accessions showed also lower stability, being particularly adapted to Delta Nile conditions. On the contrary, accessions Ls12 and Ls14 were more adapted to rain fed Spanish conditions. Accessions Ls7, Ls1 and Ls3 were the most stable over environments for grain yield.