Evaluation of Rooting in Lateral Shoots and Nodal Stem Cuttings of Leucaena (L . Leucocephala and L. Diversifolia) Clones for Clonal Propagation

Abstract

Clonal propagation method was developed for Leucaena clones (L. leucocephala and L. diversifolia) using lateral shoots which gave many advantages over the conventional method of using nodal stem cuttings. Lateral shoots of 25-30 cm length with apical buds emerging at 30-60° angle from stock plants maintained in sand beds gave higher rooting than nodal stem cuttings. Anatomical configuration of stem cuttings taken at positions 1-4 from shoot apex differed significantly between lateral and nodal cuttings and E. camaldulensis used as control. Rooting was significantly higher (87%) at 25-30 cm length (position 4) in lateral shoots (where vessel frequency was highest) compared with other positions (28-43%) and nodal cuttings (16-53%), whereas Eucalyptus stem cuttings had higher frequency of vessels of lower diameter and > 80% rooting at all positions. Rooting occurred in Leucaena lateral shoots within 20 days of misting with roots emerging all around the stem along a length of 2 cm from base of the cutting. Lateral cuttings produced significantly higher number of roots (22 roots per plant) than nodal cuttings (6 roots per plant) with significant reduction in nursery period (60 days), better rooting (> 80%) and root architecture.

Variation in Rooting Pattern of Leucaena leucocephala in Relation to Propagation System and Stock Mother Plants

“…The study was conducted during the period November 2017-May 2018 in the commercial nursery of Paperboards and Specialty Papers Division (PSPD), ITC Ltd. located at Bhadrachalam (17°40 / N latitude and 81° E longitude) in Telangana state in India. Mother plants in sand beds and CMA were pruned to 15 cm height in November 2017 for production of lateral shoots that emanate from the dormant lower buds at 30-45 degrees angle to the main stem (Suraj and Varghese, 2019). Lateral shoots with apical bud were harvested after repeated pruning to ensure that shoots emerged at an angle to main stem.…”

“…The nursery site has a tropical humid climate with mean annual temperature of 35° C, maximum temperature of 49° C during summer (April-June), minimum temperature of 10° C during winter (December-January), mean relative humidity of 70-80% and annual rainfall of 1,100 cm. The mother plants were provided nourishment (Suraj and Varghese, 2019) through controlled drip irrigation system. Lateral shoot cuttings of 25-30 cm length were harvested from each type of mother plant and planted in rooting medium (vermiculite-coirpith in 2:1 ratio) in 93cc hycotrays of 40 cells after dipping the base of cutting in IBA (5,000 ppm).…”

“…For experiments (a), (b) and (c) 2,000 cuttings each (10 trays of 40 plants each ×5 replications) were used and for (d), transverse sections were taken from the base of 15 cuttings of each category of mother plant. Nursery protocol developed for Leucaena clones (Suraj and Varghese, 2019) was followed.…”

“…In Leucaena, nodal cuttings from CMAs in open field, and minicuttings from intensively managed mother plants did not give similar success as in eucalypts due to specific characteristics of stem and turgor based responses in leaflets of Mimosaceae (Visnovitz et al, 2007). Lateral shoots produced by modification of shoot orientation in stock mother plants gave encouraging results compared to apical and nodal stem cuttings in Leucaena (Suraj and Varghese, 2019).…”

“…Application of rooting hormone and selection of juvenile cuttings from suitable stem positions were found to be critical for good rooting in Leucaena clones and hybrids (Shi and Brewbaker, 2006). A propagation technique was recently developed using lateral shoots from stock mother plants, maintained in sand beds, that give more than 80% rooting compared to conventionally used nodal stem cuttings (Suraj and Varghese, 2019). This propagation method was successfully implemented for large scale supply of clones to farmers for enhancing wood yield in plantations.…”