with 5 μM zeatin and routinely micropropagated through nodal sections to increase the number of clonal shoots available for rooting trials. Rooting of microshoots and acclimatization of plants to the greenhouse. Microshoots (2 to 3 cm in length) were
Kaitlin J. Palla, Rochelle R. Beasley, and Paula M. Pijut
Karla Gabrielle Dutra Pinto, Sônia Maria Figueiredo Albertino, Bruna Nogueira Leite, Daniel Oscar Pereira Soares, Francisco Martins de Castro, Laís Alves da Gama, Débora Clivati, and André Luiz Atroch
mechanisms of rooting, such as different hormone balances between guarana cultivars ( Azevedo et al., 2015 ; Pacurar et al., 2014 ). Therefore, the endogenous concentration of rooting promoters or inhibitors may dispense or require the application of
J. Naalamle Amissah, Dominick J. Paolillo Jr, and Nina Bassuk
Oaks ( Quercus L.) are among the most important hardwood species in North America. Unfortunately, due to difficulty in vegetative propagation, hybrids and unique types of oaks are rarely introduced into the nursery trade. Poor rooting ability
Ningguang Dong, Qingmin Wang, Junpei Zhang, and Dong Pei
The relationship between auxin and adventitious root formation has been studied for many years. Indole-3-acetic acid plays a central role in adventitious rooting and was the first plant hormone used to stimulate the rooting of cuttings ( Cooper
W. Roland Leatherwood, John M. Dole, Ben A. Bergmann, and James E. Faust
growth under water stress and aiding adventitious root formation ( Clark et al., 1999 ; Mergemann and Sauter, 2000 ; Sharp and LeNoble, 2002 ; Stepanova and Alonso, 2005 ). Research shows that ethylene injury may be prevented through chemical
Amy J. MacKenzie, Terri Woods Starman, and Mark T. Windham
Trichoderma harzianum Rifai, a fungus that controls soilborne pathogens, can enhance growth of several vegetable and floriculture crops. Zero, 5, or 25 g of T. harzianum (isolate T-12) peat–bran amendment was added per kilogram medium in an effort to enhance the rooting of four chrysanthemum [Dendranthema ×grandiflorum (Ramat.) Kitamura] cultivars, two considered easy to root (`Davis' and `White Marble') and two considered hard to root (`Dark Bronze Charm' and `Golden Bounty'). Adding the T. harzianum amendment at both rates tested increased root and shoot fresh weights during 21 days of rooting, relative to the control. Supplementary treated cuttings were transplanted into nontreated growing medium after 21 days. Midway between transplant to flowering, increases in height, shoot dry weight, and root fresh and dry weight were detected in `Dark Bronze Charm' with T-12, relative to the control; increases in height, shoot fresh and dry weight, and number of nodes were detected in `Golden Bounty' with T-12. By this time, there were no detectable differences in `Davis' or `White Marble'.
James F. Harbage and Dennis P. Stimart
We investigated the role of ethylene on adventitious rooting of `Gala' (easy-to-root) and `Triple Red Delicious' (difficult-to-root) apple (Malus domestica Borkh.) microcuttings. Root count increased significantly as IBA level increased, with highest root counts on `Gala'. Ethylene evolution increased significantly with IBA level without significant differences between cultivars. Basal section removal of microcuttings in the area of root origin reduced root count without changing ethylene evolution. Ethylene treatment of proliferated shoots before microcutting excision failed to enhance rooting. IBA-induced ethylene evolution was eliminated nearly by AVG, but root count remained IBA dependent. ACC reversed IBA plus AVG rooting inhibition, but ACC alone failed to influence root count. Polar auxin transport inhibitors NPA and TIBA stimulated ethylene evolution without increasing root count. Adventitious rooting of apple microcuttings was not associated with ethylene. Chemical names used: 1-H-indole-3-butyric acid (IBA); aminoethoxyvinylglycine (AVG); 1-aminocyclopropane-1-carboxylic acid (ACC); 2,3,5-triiodobenzoic acid (TIBA); N-1-naphthylphthalamic acid (NPA).
Jun Chen, Dengru Wu, Francis H. Witham, Charles W. Heuser, and Richard N. Arteca
Adventitious root formation (rooting) in `Berken' mungbean [Vigna radiata (L.) Rwiclz.] cuttings is stimulated by indole-3-acetic acid (IAA). To understand the molecular events that occur during IAA-induced adventitious root initiation, a λgt11 cDNA library was made from mungbean hypocotyls treated with 500 μm IAA for 3 hours and differentially screened. Two cDNAs MII-3 and MII-4 were isolated. Southern analysis revealed that both cDNAs are encoded by different genes. Expression studies showed different patterns for both genes. Both MII-3 and MII-4 were highly expressed in IAA treated hypocotyls, whereas MII-4 was also induced in IAA treated epicotyls. There was no expression of either MII-3 or MII-4 in control or IAA treated leaves. With increasing concentrations of IAA from 100 to 1000 μm there was an increase in the average root number per cutting as well as a stimulation in MII-3 and MII-4. Both MII-3 and MII-4 showed a stimulation in expression 4 hours following treatment with 500 μm IAA reaching a maximum from 4 to 8 hours followed by a decline thereafter. Basal expression of MII-3 was evident between 2 and 8 hours, whereas, a high degree of basal expression was found with MII-4 from 1 to 8 hours followed by a sharp decline. Cycloheximide (50 μm) dramatically reduced rooting and MII-3 expression, whereas MII-4 was only slightly affected.
Sezai Ercisli, Ahmet Esitken, and Fikrettin Sahin
During Fall and Winter 1999-2000 and 2000-2001, a study was conducted to evaluate the effects of exogenous IBA application (0, 2000, or 4000 ppm) and inoculation with Agrobacterium rubi (strains A1, A16, or A18) alone or in combination with each bacterial strain on rooting of hardwood stem cuttings of two rose selections (ERS 14, Rosa canina, and ERS 15, Rosa dumalis). Treatments of hardwood stem cuttings with IBA, bacteria alone and in combination with IBA were found to promote rooting. The highest rooting percentage was obtained among ERS 14 cuttings when treated with 4000 ppm IBA plus A. rubi A16. However, optimal rooting of ERS 15 was obtained when treated with 2000 ppm IBA plus A. rubi A18. Better rooting was observed in thornless ERS 15 genotype than in thorny ERS 14 genotype in both years. Chemical name used: 1H, indole-3-butyric acid (IBA).
Hatice Gulen, Yasar Erbil, and Atilla Eris
A stock plant etiolation treatment was tested to improve rooting of the important cherry rootstock Gisela-5. To create the etiolation effect, at the beginning of the growing season, banding (blanching) was initiated on stock plants by placing black plastic tape at the base of new shoots for 6 or 10 weeks. Cuttings were excised so that the banded area was at the cutting base. IBA was applied at two concentrations (5 and 10 mm) to the cutting base following wounding and cuttings were placed in perlite (100%) rooting medium under mist. The rooting percentage, number of roots per cutting and root length were measured 4 weeks after planting. Banding and duration significantly stimulated rooting of leafy softwood cuttings. The highest rooting percentage (80.0%) was obtained on cuttings banded for 6 weeks and treated with 5 mm IBA.