In vitro propagation of white lupin (Lupinus albus l.) from shoot tip explants

Abstract

Lupinus albus, commonly known as white lupin, is used as food, medicine and to maintain soil fertility. Low yield and high alkaloid content are among the major constraints of this crop. Plant tissue culture that usually starts with in vitro propagation as pre-requisite can be used for crop improvement. Therefore, the objective of this study was to develop in vitro propagation protocol for this crop. The seeds were sterilized with sodium hypochlorite and cultured on growth regulators free MS medium. Shoot tips from in vitro germinated seedlings were cultured on MS medium supplemented with 0.5 and 1.0 mg/l BAP or kinetin alone. The shoots were cultured on half strength MS medium containing BAP (0.0, 0.5, 1.0, 1.5 and 2.0 mg/l) in combination with kinetin (0.0, 0.5, 1.0, and 1.5 mg/l) and NAA (0.0, 0.01, 0.1, 0.5 and1.0 mg/l) for shoot multiplication. The multiplied shoots were cultured on half strength MS medium supplemented with 0.01 mg/l IBA, 0.1 mg/l IAA or 0.5 mg/l NAA for rooting. Seeds sterilized with 1.5% sodium hypochlorite for 20 min showed 100% germination. The highest mean shoot number per explant (7.53±0.64) was obtained on medium supplemented with 2.0 mg/l BAP in combination with 0.5 mg/l kinetin. The highest mean root number per shoot (18.36±1.28) and mean root length (3.43 ±0.13 cm) was obtained on half strength MS medium supplemented with 0.01 mg/l NAA. After one month of acclimatization, 90% of the plants survived. This protocol can be used` for genetic improvement of Lupinus albus using biotechnological approaches.