Nelumbo nucifera Raw sequence reads. Nelumbo nucifera

In traditional production, the rhizome (product organ) is often used as ‘seed’, and thus mutation through hybridization and the fixation of variation by asexual propagation are the main methods used to create new varieties. As this results in a relatively under-developed principle root, adventitious root exert a critical role in water and nutrient uptake in lotus. Hybrid lotus plants have a longer seedling period because of the slow rate of emergence and low number of adventitious roots. The effects of plant hormone regulatory pathways will help clarify the mechanism of adventitious roots formation, which undoubtedly is helpful to accelerate lotus breeding process. For IAA treatment, The coat of Taikong lotus seeds were punched for convenient absorption of water, and then germinated in water (28°C/darkness, about 4 d for germination). The germinated seeds were treated with various concentration of IAA (10 μM, 50 μM, 100 μM, and 150 μM) for 2 d before being transferred to water for continuous growth. The containers were placed in a light incubator with temperatures of 28°C/day and 22°C/night, a diurnal cycle of 16 h light/8 h darkness, and a light intensity of 200 m-2s-2 for the whole experimental period. For each experiment, the number of adventitious root were counted every day after adventitious root began forming at the hypocotyls (about 4~5 days after germination), with triplicate experiments carried out for each treatment.