Optimization of in vitro rooting protocol for tomato (Lycopersicon esculentum mill.) varieties
In vitro rooting of micropropagated shoots were carried out with the aim of evaluating the root induction responses of two tomatoes (Lycopersicon esculentum MILL) varieties (Gelilema and Chali) using Indole -3- butyric acid (IBA). Seven levels of IBA (0.0, 0.25, 0.5, 0.75, 1.0, 1.25 and 1.5 mg L-1) were used in a completely randomized design (CRD) in factorial combinations (seven level of IBA*two varieties) with three replications. After the plantlets were kept in the rooting media for three weeks, data on rooting percentage, number of roots/shoots and root length in cm were collected. The analysis of variance showed that the interaction of IBA*Var was highly significantly different for rooting percentage, a number of roots/shoot and root length at p<0.01. The highest rooting percentage (100.00±0.00), number of roots/shoot (14.20±0.35) and root length (10.7±0.29) were received from Chali on free Murashige and Skoog medium (MS). At the same time, the lowest percentage of rooting (11.11±0.00), number of roots/shoot (0.887±0.19) and root length (1.00±0.00 cm) were obtained from Gelilema on MS+1.5mg/l IBA. For acclimatization, the in vitro rooted shoots were transplanted into plastic pots containing a mixture of oven sterilized soil and sand at a ratio of 2:1. After three weeks, a survival rate of 67.7% for Chali and 58.1% for Gelilema was obtained. From the above result, it can be concluded that free MS medium was the best for in vitro rooting of the two tomato varieties. The optimized protocol will be useful for rapid in vitro multiplication of the two tomato varieties.