Adventitious rooting in stem and rhizome cuttings of Tuscan (Italy) Vaccinium myrtillus L. under different environmental conditions

BACKGROUND: There is no mention in the literature of vegetative propagation of Vaccinium myrtillus. OBJECTIVE: The aim of the study was to evaluate the rooting potential of bilberry rhizome and stem cuttings. METHODS: Rhizome and stem cuttings collected in early Autumn were dipped in different IBA solutions (0 – 2000 – 4000 mgL–1) and rooted in non-sterilized V. myrtillus soil and expanded perlite under controlled growth chamber environment or under mist with basal heating in a greenhouse for 12 weeks. RESULTS: Rhizome cuttings showed high rooting potential in plant growth regulator (PGR) free substrates. Conversely, stem cuttings took advantage from IBA treatments; this positive effect on rooting percentage was synergistically increased when rooted in agriperlite. A higher rooting capacity was achieved when rhizome and stem cuttings were placed in agriperlite, however number of developed roots and shoots were much higher when V. myrtillus turf was used as substrate. Mist and bottom heating did not improve rooting significantly. CONCLUSIONS: V. myrtillus can be successfully propagated both by rhizome and stem cuttings. With an overall rooting success of 56–68% and with a reasonably good growth rate, production of planting material from stem cuttings of V. myrtillus offers opportunities for a cheaper, practically feasible and technically less demanding alternative means of propagation.

Effects of location, gender and indole butyric acid on rooting of Laurus nobilis L. semi-hardwood stem cuttings

The research was conducted in 2018 in order to investigate the effect of location, tree gender and indole butyric acid (IBA) 4000ppm on rooting of semi-hardwood stem cuttings. Two locations (Al-Samrah and Al-Nabaeen) in Latakia province, Syria, different in latitude and above sea level (500 m and 827 m, respectively) were studied. The results showed significant effect (p<0.05) of the location and tree gender on rooting capacity. No rooting was observed in control (without IBA treatment). Location also affected the number of roots/cuttings. No effect of location or tree gender on root length and diameter was established. The highest rooting rates (%) were for cuttings taken from female trees from Al-Samrah location when treated with IBA 4000 ppm (82.2%).

Cutting propagation of ‘Cambona 4’ yerba mate clones

The ‘Cambona 4’ yerba mate (Ilex paraguariensis A. St. Hil. - Aquifoliaceae) stands out for the high productivity and soft taste of the raw material obtained. The seedlings come from the controlled crosses of a female and a male plant. In order to guarantee the planting of even more uniform and productive herbs, the cutting is an alternative of propagation. The objective of this research was to evaluate the rooting capacity of apical and subapical cuttings of six ‘Cambona 4’ clones (C7, C8, C9, C10, C11 and C13) in two seasons, in january (summer/autumn) and april (autumn/winter) treated with 2.000 mg/kg of IBA in the form of talc. The cuttings were standardized with 10 cm, keeping a pair of leaves cut in half. The cutting was done in an agricultural greenhouse, with irrigation by intermittent nebulization, the cuttings were placed to rooting in plastic tubes containing carbonized rice husk. After 120 days, it was verified that the cutting season influenced the response of each clone, but for most clones rooting was higher when performed in summer/autumn, with better rates varying between 78.2% to 90.6% (C8, C9, C11 and C13), while in autumn/winter it was from 59.4% to 75.0% (C7, C10, C11 and C13). In the summer/autumn cutting period, subapical cuttings showed greater survival and rooting than the apical ones, but they didn’t differ when performed in autumn/winter. Leaf retention positively influenced the survival.

Survival and growth of white poplar rooted cuttings regarding term of planting

White poplar nursery production is mainly based on vegetative propagation hardwood cuttings. In this study the reaction of three clones of white poplar (Populus alba L.) on term of cuttings' preparation and planting according to parameters of survival and growth of rooted cuttings in three nurseries in Northern part of Serbia. There were two terms of cuttings' preparation and planting examined: a) mid-March and d) the beginning of April (standard term). Obtained results suggest considerable differences between nurseries and between examined terms. Differences between clones were not significant, but there were found significant effects of interactions of factor Clone with other two main sources of variation. The best results were obtained by cuttings that were prepared and planted in mid-March, due to faster growth and survival of rooted cuttings. The positive effect of the earlier term is evident particularly in clones L-12 and L-80 and enable feasible production of rooted cuttings of these clones, especially in nurseries that obtained better conditions. Results obtained in this study suggest that influence of terms of cuttings' production and planting is important issue concerning introduction of clones with relatively poor rooting capacity, optimization of nursery technology of experimental white poplar clones, and improvement of white poplar nursery production in general.

Western thuja (Thuja occidentalis L.): introduction in Siberia and use of nanoparticles in increasing the green cuttings rhizogenic activity

Western thuja (Thuja occidentalis L.) as a representative of evergreen coniferous species is of particular importance in the landscape gardening of urbanized territories in Siberia. An integral assessment of the introduction prospects based on the study of winter hardiness, regularity of shoots growth in height and other parameters showed that Western thuja in the soil and climatic conditions of Krasnoyarsk belongs to a promising taxon (86 points out of 105). For the purpose of widespread use of the introduced plant in the landscape gardeningpractice, a method for increasing the rooting capacity of Western thuja green cuttings is proposed. Soaking green cuttings in a solution of indolyl-3-acetic acid with citric acid and adding nanoparticles of biogenic ferrihydrite doped with aluminum increases the rhizogenesis of the cuttings material by 10-20%.

Optimization of rhizogenesis for in vitro shoot culture of Pinus massoniana Lamb.

The rooting capacity of Pinusmassoniana is poor, especially for mature trees, and has prevented the development of clonal forestry for P.massoniana. In this study, we varied explant types, subculture times and exogenous hormones for plantlet regeneration and assessed shoots for rooting rate and root number for P.massoniana. Following five repetitive grafts, new shoots from grafts used as explant sources were rejuvenated as observed from juvenile shoot morphology and anatomy, leading to greatly enhanced plant regeneration in comparison to that of mature materials from 26-year-old P.massoniana trees. The rooting capacity of subcultured shoots increased with successive subcultures, reaching a peak at 20 subcultures with 35–40 days per subculture. However, rooting performance was significantly reduced after 30 subcultures. The addition of naphthaleneacetic acid (NAA) plus indoleacetic acid in the medium improved the root number, but the combination of exogenous NAA with paclobutrazol (PBZ) increased rooting rate and root number. We thus greatly improved the rooting capacity of mature P.massoniana trees by optimizing explant types (rejuvenated), subculture times (20 subcultures, 35–40 days per subculture) and addition of NAA + PBZ to the rooting medium. The conditions can be used for efficient plantlet regeneration of P.massoniana.

BIOFERTILIZERS AND BIOCONTROLLERS AS AN ALTERNATIVE TO THE USE OF CHEMICAL FERTILIZERS AND FUNGICIDES IN THE PROPAGATION OF YERBA MATE BY MINI-CUTTINGS

ABSTRACT The production of yerba mate seedlings through seeds has several limitations, which can be overcome by ex vitro vegetative propagation techniques such as the mini-cuttings, in which it is usually necessary to use synthetic chemical fertilizers and fungicides. However, there is a tendency towards sustainable agriculture, using biofertilizers (growth-promoting bacteria) and biocontrollers (Trichoderma sp.). Therefore, the objectives of this work were to evaluate the effect of biofertilizers on the production of mini-cuttings from yerba mate mini-stumps; as well as the effect, of biocontrollers on survival and rooting capacity of mini-cuttings. Strains of Bacillus sp. and Trichoderma asperelloides of yerba mate were used under two radiation conditions. There was a positive relationship between the availability of radiation and the production of mini-cuttings and the rooting capacity. All the mini-stumps sprouted regardless of treatments. The largest production of viable mini-cuttings occurred in a situation of high radiation and fertilization; while the treatments with growth-promoting bacteria and high radiation had intermediate values. The mini-cuttings inoculated with Trichoderma asperelloides had higher rooting percentage, greater number and length of roots than the mini-cuttings treated with fungicide. Therefore, we demonstrated that the use of chemical products can be replaced by biological ones and achieves acceptable yields.