This study presents results of a comparison between 12 clones, derived by clone selection, with peppermint "Mitcham". Clones differed over herb, leaf and essential oil yield. The average values of productive traits of one of clones (the clone 15) were significantly higher than the corresponding values of the check.
Key words: peppermint, clones, productive traits.
According to phylogeny, the most distributed peppermint (Mentha x piperta L.) is of a hybrid origin, derived by spontaneous crossings of several species of the genus Mentha (Heeger, 1956). This hybrid origin of peppermint affects heterozygosity and development of various forms within species, and deriving of different genotypes in populations and varieties. The presence of inter-variety autosterility and the phenomenon of trait transgression in generative reproduction led to vegetative reproduction of peppermint (Dražić, 1998).
Vegetative multiplication provides that favourable genotypes can be derived in the process of breeding and remained constant in the course of reproduction regardless of genetic constitution of the selected plant. The idea of the application of the method of individual selection in choice of the best clones is to achieve as greater uniformity for the most important traits as possible (Tucović, 1975; Borojević and Borojević, 1976; Borojević 1981; Marinković et al., 1981; Dražić, 1998).
The aim of this study was to observe productive traits of newly developed peppermint clones.
Clones were derived by clone selection of peppermint populations at the location of their growth. Selected clones were compared with the peppermint "Mitcham". The 3-replicate trails were set up in the experimental field of the Institute in 1998 and 1999. The appropriate growing practices were applied. The elementary plot size amounted to 5 m2.
The following properties were analysed in this study: plant height, leaf area, herb, leaf and essential oil yield, as well as, harvest index. Means, variance and coefficient of variance were evaluated. The obtained results were statistically processed by the analysis of variation, while significance was evaluated by the F and LSD tests.
Results of the analysis of variance point to the presence of significant differences in yields of herb, leaf and essential oil among observed clones. Coefficients of variation ranged from 42% to 59% indicating to the greatest variability of these traits (Table 2).
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| LSD |
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The highest herb yield (2316 kg ha-1) was detected in the clone 15. The yield increase of 17% in relation to the check proved to be statistically justified. Beside herb yield, reliably highest yields of leaf (1261 kg ha-1) and essential oil (37.3 kg ha-1) were determined in this clone. This increase expressed in relative amounts was 16%, i.e. 28%, respectively (Table 1).
This indicates to the possibility to derive clones with yielding potential greater than those detected in the existing genotypes. High values of productive traits, close to the values of the check, were determined in the clones 7 and 20. Yields of herb, leaf and essential oil were 1859, 10,634 and 33.5 kg ha-1, respectively, in the clone 7, while the corresponding values for the clone 20 amounted to 1884, 975 and 32 kg ha-1. Biomass yield of the clone 39 was similar to yields of clones 7 and 20. However, essential oil yield was significantly lower (Table 1).
Other clones were below the level of the check and the lowest yields were detected in clones 64, 43, 37 and 21. This points out the fact that there were more clones with lower that higher values of productive traits than the check.
The values of plant height, leaf area and harvest index, as well as, yield components were similar in all observed genotypes (Table 1). The average plant height, leaf area and harvest index amounted to 50 cm, 11 cm2 and 0.54, respectively.
| Traits |
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| Height (cm) |
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| Leaf area (cm2) |
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| Herb yield (kg/ha) |
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| Leaf yield (kg/ha) |
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| Essential oil yield (kg/ha) |
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| Harvest index (Hi) |
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This study showed that values of productive traits were higher in the check than in many of observed clones. Prospective clones, especially the clone 15, with significantly higher yields of herb, leaf and essential oil, should be further observed in experiments in order to select the best.
Borojević S., Borojević K. (1976): Genetika, Novi Sad, 22.
Borojević S. (1981): Principi i metodi oplemenjivanja bilja, R.U. "R. Ćirpanov", Novi Sad, 305-310.
Dražić S. (1998): Oplemenjivanje i održavanje genetičkog identiteta sorti i vrsta iz roda Mentha, 73-85, U: Pitoma nana (Mentha x piperita L.) i druge vrste roda Mentha, Monografska studija, IPLB, Beograd.
Heeger F. E. (1956): Mentha piperita L., Pfefferminze, Handbuch des Arznei und Gewiirzpflanzenbaues Dragengewinnung, Leipzig - DDR, 512-541.
Marinković D., Tucić N. i Kekić V. (1981): Genetika, NK Beograd, 362-364.
Tucović A. (1975): Praktikum iz genetike sa oplemenjivanjem bilja, Beograd, 142-173.