Mini-cuttings: an effective technique for the propagation of Pinus pinaster Ait.
ABSTRACT Pinus pinaster Ait. is one of the main forest tree species planted in Spain, Portugal and France. Due to its high economic relevance, there
is considerable interest in developing techniques for vegetative breeding aimed at mass propagation. In this study we present
a mini-propagation protocol in order to define an efficient method to propagate families or clones of P. pinaster. We carried out three experiments using mini-cuttings of 3–5cm in length with the aim of evaluating the effects of temperature
(4°C vs. 25°C), plant growth regulator (IBA) and shoot age on rooting ability. Percentage of rooted cuttings and morphological
root variables were recorded. The percentage of rooted cuttings per treatment ranged from 68 to 97%. Treatment with IBA significantly
influenced the rooting process at 25°C but not at 4°C. The number of apexes, length, area and volume of roots were all positively
affected by temperature treatment. Shoot age also had a positive effect on rooting capacity of cuttings, with the cuttings
from the youngest shoots (70days after pruning) having higher rooting percentages, ranging from 84.7 to 98.3%. The use of
juvenile material, good environmental conditions and IBA all benefited the rooting of clonal material, resulting in high rooting
capacity. This study presents an innovative propagation protocol for P. pinaster that can be used as a tool in breeding programs.
KeywordsMaritime pine–Vegetative propagation–Rooting–Shoot age–Indolebutyric acid–Temperature
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ABSTRACT: Adventitious rooting, a key step in clonal propagation is affected by tree maturation. Micropropagation followed by microcuttings propagation has the potential to rejuvenate the clones thereby enhancing the rooting potential and minimize intra clonal variation. In this study, 33 superior performing Eucalyptus camaldulensis clones were propagated by rooting of stem cuttings (SCs) and micropropagation. Micropropagated plantlets were used as stock plants for microcutting propagation. Rooting of SCs and micropropagation was carried out with the coppice shoot cuttings and axillary buds respectively, obtained from approximately fourteen year old trees that had undergone one vegetative propagation cycle. The adventitious rooting recorded was significantly higher in micropropagation (24.8–100 %) and microcuttings (43–95 %) than SCs method (9.3–75.5 %). Studies on ontogeny of adventitious rooting showed the emergence of root primordium from the phloem region and root initials were noticed within 5–9 days after auxin treatment. Further, molecular marker analysis showed genetic uniformity except for two ramets, detected using inter simple sequence repeats (ISSR) markers and suitable corrective measures were taken to avoid entry of such plantlets for mass multiplication. This study demonstrates the importance of integration of micropropagation and microcuttings production for rejuvenation and mass multiplication. Although current rejuvenation and root induction treatments favored adventitious rooting, the basic mechanisms involved in rejuvenation and adventitious rooting need to be explored for hassle free industrial rooting process, consequently cost effective propagation.New Forests 12/2014; DOI:10.1007/s11056-014-9465-1 · 1.78 Impact Factor
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ABSTRACT: There is a concern on how emerging pests and diseases will affect the distribution range and adaptability of their host species, especially due to different conditions derived from climate change and growing globalization. Fusarium circinatum, which causes pitch canker disease in Pinus species, is an exotic pathogen of recent introduction in Spain that threatens its maritime pine (P. pinaster) stands. To predict the impact this disease will have on the species, we examine host resistance traits and their genetic architecture. Resistance phenotyping was done in a clonal provenance/progeny trial, using three-year-old cuttings artificially inoculated with the pathogen and maintained under controlled environmental conditions. A total number of 670 ramets were assessed, distributed in 10 populations, with a total of 47 families, 2 to 5 half-sibs per family, and 3–7 ramets per clone. High genetic variation was found at the three hierarchical levels studied: population, family and clone, being both additive and non-additive effects important. Narrow-sense and broad-sense heritability estimates were relatively high, with respective values of 0.43–0.58 and 0.51–0.8, depending on the resistance traits measured (lesion length, lesion length rate, time to wilting, and survival). These values suggest the species' high capacity of evolutionary response to the F. circinatum pathogen. A population originated in Northern Spain was the most resistant, while another from Morocco was the most susceptible. The total number of plants that did not show lesion development or presented a small lesion (length<30 mm) was 224 out of 670, indicating a high proportion of resistant trees in the offspring within the analyzed populations. We found large differences among populations and considerable genetic variation within populations, which should allow, through natural or artificial selection, the successful adaptation of maritime pine to pitch canker disease.PLoS ONE 12/2014; DOI:10.1371/journal.pone.0114971 · 3.53 Impact Factor
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ABSTRACT: The goal of this project was to study how fungal communities in Mediterranean forests dominated by Pinus pinaster are influenced by different edaphoclimatic conditions, characterized by three different edaphoclimatic sites composed of siliceous, calcareous, and sandy soils. Sporocarps were collected and identified from nine 100 m 2 permanent plots, three in each site, during the autumn seasons from 2006 to 2012. The data collected were used to assess fungal productivity and diversity. Fungal community composition was mainly correlated with climatic variables, such as precipitation and temperature. Additionally, soil nitrogen and potassium significantly influenced the distribution of species for both saprotrophic and mycorrhizal functional groups. Some fungi such as Lycoperdon perla-tum, Russula torulosa, and species within the genera Galerina and Mycena were adapted to a broad range of ecological conditions. Others were found only in very specific environmental conditions. All species within Macrolepiota were collected in the calcareous soils, whereas Laccaria laccata and L. bicolor were exclusively associated with higher amounts precipitation and nitrogen in the siliceous plots. These findings have ecological implications that are important for managers seeking new options for adding economic value and for sustaining biological diversity in these Mediterranean forests.