Efficient Propagation Technique of Euphorbia ×lomi Thai Hybrids

A simple and efficient in vivo propagation protocol of two cultivars of Euphorbia ×lomi Rauh is described. Mother plants of ‘Nguen Muang’ and ‘Porn Ying Yai’ were soilless grown in 1 coconut coir dust:1 perlite (by volume) and 2 sphagnum peat:1 perlite (by volume) to produce cuttings. Plants cultured in peat-based substrate showed thicker stems (36.0 versus 30.5 mm, respectively), higher production of cuttings (10.4 versus 5.6 per plant), higher water absorption (265.7 versus 153.5 mL/plant/d), and higher content of nutrients in the root zone as compared with those cultivated in coir dust mixture. Cuttings harvested from 1-year-old mother plants of both cultivars were treated with 4000 ppm of α-naphthalene acetic acid (NAA) powder and inserted into bottom-heated benches filled with different substrates [perlite, 1 perlite:1 coir dust (by volume), coir dust] for rooting. Cuttings in pure perlite evidenced higher rooting percentage (86.2%) and longer roots (6.2 cm) than those in other media. Application of NAA resulted in higher rooting capacity (78.8 versus 68.3%, respectively) and higher amount of roots per cutting (13.4 versus 10.2) than treatment without auxin. Rooted cuttings grown in 1 peat:1 perlite medium (by volume) produced higher marketable potted plants than in 2 peat:1 perlite medium.