Maria Papafotiou

Cotton gin trash compost and rice hulls as growing medium components for ornamentals

Summary Rooted cuttings of Dendranthema grandiflora Tzvelev., Nerium oleander L. and Lantana camara L., as well as seedlings of Pelargonium zonale L. were grown in media containing cotton gin trash compost, rice hulls, peat and perlite in various ratios, and their vegetative growth and flowering was determined and compared with a control medium of 1 peat:1perlite (by volume). When up to 60% of peat in the control medium was replaced by cotton gin trash compost plant height was slightly reduced, except in P. zonale, the number of flowers was increased, except in pot D. grandiflora, and flowering was accelerated in all species except N. oleander. When half or all the perlite of the control was replaced by rice hulls, plant height and flower number was similar to that of the control plants, except in pot D. grandiflora where the number of flowers was reduced and in cut D. grandiflora where both stem length and flower number were reduced; also, in L. camara total replacement of perlite by rice hulls gave shorter plants. In media that contained cotton gin trash compost, peat and rice hulls, plant height of all species except P. zonale was reduced. Partitioning of cotton gin trash compost or rice hulls in the media decreased their total porosity and their easily available water, while cotton gin trash compost increased bulk density. When rice hulls totally replaced the perlite, bulk density was decreased. The media with peat, cotton gin trash compost and rice hulls and the one with peat and rice hulls had the lowest easily available water and total porosity of all the media tested. Media with cotton gin trash compost had a high electrical conductance at the beginning of the culture period, but it fell to the level of the control by the end.

In vitro plant regeneration of Mammillaria elongata normal and cristate forms

In the normal form of Mammillaria elongata, shoots were regenerated in vitro, through callus, from tubercle explants excised from the upper part of the branch and cultured on Murashige and Skoog medium (MS) with 1.07 μM α-napthaleneacetic acid (NAA) and 22.20 μM 6-benzylaminopurine (BA). A high percentage of tubercles explants of the M. elongata cristate form, excised from the tip of the branch and cultured on MS with 0.54 μM NAA and 0.44 μM BA or 1.07 μM NAA, responded by initially forming an inflated cristate shoot, which gave cristate and normal shoots, without callus intervention, when transferred on basal MS. Callus formed on cristate tubercles explants gave both cristate and normal shoots when transferred onto basal MS. Normal and cristate shoots were rooted in vitro on MS with 9.84 μM or 0.98 μM indole-3-butyric acid, respectively, and established ex vitro. In both normal and cristate form, the differential response appeared to be associated with the site of the explant excision. The formation of shoots was influenced by the season of culture; i.e., explants excised in October had a higher shoot formation rate than those excised February.

Micropropagation of Arbutus unedo, A. andrachne, and their natural hybrid, A. x andrachnoides from seedling explants

Summary Micropropagation of Arbutus unedo, A. andrachne, and A. x andrachnoides could facilitate their use as ornamental, forestry and medicinal plants, while the use of in vitro-grown seedlings as stock material could solve contamination and seasonality problems. Seeds germinated at high rates (87 – 99%) at 15ºC on half-strength Murashige and Skoog (MS) medium after 24 – 30 d, depending on the species. Nodal explants were excised from 2-month-old seedlings grown on MS medium or on woody plant medium (WPM) salts supplemented with 100 mg l–1 myo-inositol, 1.0 mg l–1 thiamine, 0.5 mg l–1 pyridoxine, and 0.5 mg l–1 nicotinic acid, containing 1.0 mg l–1 indole-3-butyric acid (IBA). Multiple shoots were produced from each initial culture, and from subsequent sub-cultures on MS medium or on WPM containing 2.5 or 5.0 mg l–1 zeatin (ZEA). The use of thidiazuron (TDZ) at 0.2 or 2.0 mg l–1, instead of ZEA, resulted in a reduced response and fewer shoots per explant. In addition, these TDZ-treated shoots had malformations and were very short, making them unsuitable for multiplication. The rates of multiplication on both media containing 2.5 or 5.0 mg l–1 ZEA were six- to seven-fold higher than on TDZ-containing or hormone-free media. MS medium resulted in higher rates of shoot production than WPM (4.4 – 7.8 vs. 2.2 – 5.3 shoots per explant, respectively, depending on the species and concentration of plant growth regulator) for cultures with a higher shoot proliferation potential. In contrast, WPM induced higher rooting percentages and more roots per micro-shoot (82 – 97% and 4.5 – 8.5, respectively, depending on the species and IBA concentration) compared to MS medium (42 – 64% and 3.1 – 4.1, respectively). A. x andrachnoides had a proliferation potential (4.6 shoots per explant on average on both media and ZEA concentrations) that was between the two parental species (5.9 and 3.4 shoots per explant for A. andrachne and A. unedo, respectively). Ex vitro acclimatisation and survival of plantlets in a 1:1 (v/v) mix of peat:perlite was highly successful (92 – 100%).

Teachers' Perceptions οn the Use of Botanic Gardens as a Means of Environmental Education in Schools and the Enhancement of School Student Benefits from Botanic Garden Visits

Abstract The potential of Botanic Gardens (BGs) to contribute to environmental education is well documented. To what degree this potential is met concerning school students’ environmental education is to be considered. In Greece, Environmental Education Centres (EECs) develop Environmental Education Programmes (EEPs) for schools to implement. A questionnaire survey addressing teachers employed at the EECs in Greece investigated the use of BGs as a means of environmental education and identified their most important features in supporting school EEPs. Findings indicated that the majority of EEC teachers (90.6%) have not developed EEPs involving the use of BGs, although BGs were ranked as most suitable amongst other green spaces for conducting such programmes, particularly for primary school students. Teachers identified the need for BGs to be designed accordingly and provide the necessary infrastructure to be educationally effective that included facilitating teaching (e.g. open spaces, areas to congregate, easy access paths and indoor facilities) and plant-orientated elements as well as plant management displays. A strategy by BGs to promote their role in environmental education and a multidisciplinary design approach would maximise student benefit.

Flame Weeding at Archaeological Sites of the Mediterranean Region

Archaeological sites of the Mediterranean region are widely colonized by weed species causing various problems both to the monuments and the functionality of the sites. Due to recent regulatory restrictions for herbicide use at archaeological sites, flame weeding was studied as an alternative weed management method. The objective of the study was to test two propane doses (99 kg ha-1 and 129 kg ha-1) applied two, three, or four times at three archaeological sites of Greece (Kolona, Ancient Messene and Early Christian Amfipolis). Percent weed control and weed heights were significantly affected by flaming treatments. Visual evaluation of percent weed control suggested that the propane dose of 129 kg ha-1 applied four times provided excellent weed control (>90%) for over 2 months. Annual broadleaf weeds were controlled better with flaming than grasses and perennial broadleaf species. The high propane dose applied four times reduced average vegetation height to about 10 cm, which was the desirable vegetation height wanted by the managers of the archeological sites suggesting that flame weeding has the potential to be used effectively for weed management in archaeological sites of the Mediterranean region.

Gardens and orchards of Kampos’ historical country mansions in Chios: an early trace of landscape architecture in Greece

The Greek island of Chios boasts a long and impressive history dating back to the Phoenicians, who are said to have named the island, and is situated at the Northeastern Aegean Sea, very close to t...