Genetic control of adventitious rooting traits in bi-parental pedigree of Eucalyptus tereticornis × E. camaldulensis

In commercial plantations, mass propagation and deployment of identified and tested clones has potential economic benefits. However, the major challenge is the adventitious rooting ability of high yielding genotypes. In Eucalyptus , large-scale plantations of hybrid clones with enhanced productivity are well documented. However, the understanding of genetic architecture of adventitious rooting traits in this genus is limited. The present study was conducted to decipher the genetic control of this quantitative trait in a bi-parental pedigree of E. tereticornis × E. camaldulensis. The selected parental clones used for controlled hybridization were divergent for their adventitious rooting capacity from stem cuttings. The juvenile shoots of parents and hybrids were coppiced and two-node stem cuttings were harvested and treated with 4000 mg L −1 Indole-3-butyric acid. Phenotypic variation in adventitious rooting traits was documented after 40 days of root induction in parents and 68 hybrids across two settings (March 2015 and April 2015). Significant difference in rooting percentage and number of roots was recorded between the settings. The study revealed a positive correlation between root length and rooting percentage. Broad sense heritability coefficient was the highest for rooting percentage and the predicted genetic advance was maximum for root volume (60.77%). Transgressive inheritance pattern was recorded for all rooting traits and several hybrids registered higher rooting percentage, enhanced root area and volume when compared to parents. These out-performing hybrid clones with superior root system will have potential resource use efficiency and can be deployed in arid and semi-arid zones to enhance productivity.