In vitro plant regeneration via indirect organogenesis from different explants of Lathyrus sativus L. and Lathyrus cicera L.

Abstract

The grass pea (Lathyrus sativus L.) and flatpod peavine(Lathyrus cicera L.) are the most economically important and widelycultivated Lathyrus species. However, their utilization is limiteddue to the presence of their endogenous toxin β-N-oxalyl-L-α,β-diaminopropionic acid (β-ODAP). Thus, a β-ODAP free varietyshould be developed through some plant breeding techniquelike either mutational breeding or genetic-manipulation. In thiscircumstance, the plant regeneration of Lathyrus species becomes abottleneck. In the present study, an efficient system for in vitro regenerationof L. sativus with high β-ODAP levels, and L. cicera withlow β-ODAP levels, was developed from different explants (axillarybuds, leaves and stems). At first, the green nodular calli were inducedfrom sterile seedlings. It was found that the pre-culture of sterileseedlings with 15 mg/L 6-benzyladenine (BA) was necessary for L.cicera, but not for L. sativus. All of these calli were able to differentiateinto adventitious shoot formation when cultured further. Amongthose explants, leaf segments were the optimum because of their easyobtainment and high regeneration efficiency (i.e., 66.48% in L. sativusand 62.13% in L. cicera). Furthermore, it was found that thepre-treatment would significantly improve the efficiency for nodularcalli induction in both varieties, although it was easier on explantsof L. sativus than on those of L. cicera. When these in vitro-derivedplantlets of the two Lathyrus species were planted on half-strengthMurashige and Skoog medium (MS) medium with α-naphthaleneacetic acid (NAA) supplemented, 60% of them developed severalroots. After being transplanted into soil, above 85% of each Lathyrusspecies grew well. The protocol would be useful for further expandingthe propagation and Agrobacterium-mediated genetic transformationto obtain low β-ODAP varieties.