Growth evaluation of taro cv. Bentul (Colocasia esculenta L.) diploid and tetraploid in the greenhouse in response to different soil water content for selection of drought tolerant plants

Taro (Colocasia esculenta L.) is useful as an alternative food. This plant species is popular in Indonesia, especially at Bogor, West Jawa due to many typical foods are made from taro flour having good market in that area. Taro cv. Bentul is one of the best cultivars having high productivity. Induction of tetraploid plants is aimed to obtain genotypes to have better characteristics in growth, productivity as well as to increase its genetic diversity. Selection of drought tolerant can also be conducted comparing diploid with tetraploid plants. The purpose of this study was to evaluate the growth of taro diploid and tetraploid plants in the greenhouse after treatment with different soil water content. Diploid and tetraploids plants were produced after in vitro micropropagation. Plantlets were acclimatized in a greenhouse then they were subjected for different soil water content treatment in order to select plants tolerant to drought stress. The experiment used factorial randomized complete design. The first factor was Bentul taro genotype which were tetraploid 3.3.6 and diploid clones as control treatment. The second factor was different soil water content which were at 100% of field capacity, 50% of field capacity, and 25% of field capacity. Growth was observed every week by recording length of the petiole, number of leaves, lamina length, and lamina width. Fresh and dry weight, proline content, chlorophyll concentration, roots and stomata morphology were also recorded at 12 weeks after planting. The results showed that taro tetraploid 3.3.6 had higher growth significantly difference compared to diploid (control) plant. Diploid taro has greater number of stomata densities than that of tetraploid 3.3.6 at 100% of the field capacity. Taro tetraploid 3.3.6 grown with 50% of the field capacity had higher biomass production compared to diploid taro. Therefore, tetraploid clone 3.3.6 plant could be assumed to be a drought tolerant plant.