In vitro Clonal Propagation Studies of Paulownia spp. Plants Through Nodal Explants

Abstract

The research carried out a comparative study of the micropropagation capacity of Paulownia tomentosa (Thunb.) Steud plants and 2 hybrid clones (Paulownia elongata × Paulownia fortunei) in vitro 112 and Cotevisa 2, depending on the culture media. Specificity depending on the genotyp and culture medium, regarding the number of initiation shoots per explant, was attested. The variation limits of the average values of the proliferation coefficient for the 3 genotypes fluctuate depending on the culture medium, being 0.75 ÷ 8.00 for Cotevisa 2; 0.67 ÷ 5.00 for the in vitro 112 clone and 1.00 ÷ 6.00 in the case of the P. tomentosa. The proliferation coefficient in the MS 7 variant increased by 3.16 times, 1.94 and 1.45 times compared to the MS 1, MS 2, and MS 5 media in the Cotevisa 2, and for P. tomentosa and the in vitro clone 112 1.76-1.68 and 2.48-2.12 times, respectively. Application of the ANOVA test revealed a significant influence of culture medium on the proliferation coefficient with a confidential level of 99.9%. In our experiments, the genotype and the interaction of both factors genotype-culture medium did not present a source of variation at p ≤0.05. Minishoots cut and transferred to rhizogenesis on basal MS medium supplemented with 0.2 mg•L -1 NAA and 0.4 mg•L -1 IBA started to form roots after 7 days. The established conditions that ensure 100% rate rooting and ex vitro acclimatization conditions for survival on soil substrate offer increased possibilities for mass multiplication of paulownia.