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Revista mexicana de ciencias forestales
versión impresa ISSN 2007-1132
Rev. mex. de cienc. forestales vol.7 no.38 México nov./dic. 2016
Articles
Variation of carbon distribution between the root and the aerial part in three pine species
1Facultad de Ingeniería en Tecnología de la Madera. Universidad Michoacana de San Nicolás de Hidalgo. México.
2Escuela Nacional de Estudios Superiores (ENES) Unidad Morelia, Universidad Nacional Autónoma de México. México.
The amount of carbon allocated to the shoot and root varies between species. The carbon balance of the shoot and the root is critical for survival in the field. Therefore, the objective of this study was to evaluate carbon allocation through variables of growth and root morphology in Pinus michoacan, P. pesudostrobus and P. martinezzi plants, which have variation in survival in the field. The plants were growth in nursery and watered twice a week with tap water. At 150 days, the shoot and root biomass, specific root length (SRL) and root volume (RV), and the number, diameter (RD) and length (RL) of lateral roots were evaluated. The shoot and root biomass, RV and the LER were similar between P. pseudostrobus and P. martinezii, while P. michoacana had significantly higher values of these parameters in relation to the other two species. The number, RL and RD were higher in P. michoacana as compared to P. pseudostrobus and P. martinezii and these variables were higher in P. pseudostrobus regarding to P. martinezii. The carbon allocation varied inter-species and it was higher in the variables of root morphology. Therefore, it is recommended that root morphology parameters could be taken into account as indicators of quality plant.
Key words: Root biomass; specific root length; root morphology; Pinus michoacana Martínez; Pinus martinezii E. Larsen; Pinus pseudostrobus Lindl
La cantidad de carbono destinada para la parte aérea y la raíz varía entre las especies de plantas y su balance es determinante para la supervivencia de las plantas en campo. El objetivo del presente estudio fue evaluar la distribución de carbono a través de variables de crecimiento y morfología de la raíz en ejemplares de Pinus michoacana, P. martinezii y P. pseudostrobus. El crecimiento se evaluó en vivero y las plántulas fueron regadas cada tercer día con agua corriente. A los 150 días se evaluó la biomasa de la parte aérea y de la raíz, la longitud específica de la raíz (LER) y el volumen de la raíz (VR), así como el número, el diámetro (DPRL) y la longitud (LPRL) de las raíces laterales. La biomasa de la parte aérea y de la raíz, el VR y la LER fueron similares entre P. pseudostrobus y P. martinezii, mientras que P. michoacana presentó valores significativamente mayores en dichos parámetros en relación a las otra dos especies. El número total, la LPRL y el DPRL fueron más altos en P. michoacana en comparación con P. pseudostrobus y P. martinezii; estas variables fueron superiores en P. pseudostrobus con respecto a P. martinezii. La distribución de carbono varió entre especies y fue más evidente en las variables de morfología de raíz. Por lo tanto, se concluye incluir parámetros de morfología de raíz como indicadores de calidad de planta.
Palabras clave: Biomasa de raíz; longitud específica de raíz; morfología de raíz; Pinus michoacana Martínez; Pinus martinezii E. Larsen; Pinus pseudostrobus Lindl
Introduction
Carbon distribution refers to the carbon allocated to the production of different parts of the plant (Friend et al., 1994); two theories have been proposed: the optimal (Bloom et al., 1985), which states that a plant directs it to the organ that acquires the most limiting source, and that of allometric biomass (Niklas and Enquist, 2001) which sends it to the aerial section or the root, depending on its size, calculated by dry weight or length. The amount of carbon devoted to each of these two structures depends on growth conditions and life history, and is important because it influences the survival capacity of pines after planting (South, 2000). Therefore, it is convenient to know this information in species used in reforestation and conservation.
In relation to growth conditions, a decrease in shoot mass and root mass in Pinus pinaster Ait., P. pinea L., P. canariensis C. Sm. ex DC., P. halepensis Mill. occurred in growth chamber where situations of low availability of water prevailed (Chambel et al., 2007) and in greenhouse (Aranda et al., 2010); in the latter environment the same behavior has been observed in cultivated hardwoods (Guarnaschelli et al., 2003).
On the other hand, plants confer a larger amount of carbon to build lateral roots in infertile (Paz, 2003) or humid places (Markesteijn and Poorter, 2009), as well as to make up a deep root if the seeds come from sites with low water availability and develop in greenhouses with sufficient water and nutrients (Climent et al., 2008).
Thus, the carbon distribution is subject to factors such as the provenance or scope of growth and it is feasible to evaluate it indirectly through variables associated with it, which facilitates the identification of species with better response under natural conditions. Therefore, in the hypothesis of this work it was considered that there is significant variation in the carbon distribution in species with different survival in the field: Pinus michoacana Martínez with 76 % (Gómez-Romero et al., 2012); P. pseudostrobus Lindl. from 2 to 68 % (Muñoz et al., 2011; Gómez-Romero et al., 2012) and P. martinezii E. Larsen, for their conservation value.
Materials and Methods
The variables that were considered were the fresh and dry weight of the shoot and root, specific length of the root and their morphology in seedlings of the selected species that were grown at the nursery.
A total of 6 960 Pinus martinezii seeds were collected in Los Azufres, Ciudad Hidalgo municipality, Michoacán State, México (Morales, 2014) equivalent to 100 g and the same volume for P. michoacana Martínez and P. pseudostrobus Lindl. seeds, which were provided by the Comisión Forestal del Estado de Michoacán (Forest Commission of the State of Michoacán).
From this material, one hundred seeds per species were taken for this study. A pregerminative treatment of stratification was applied, which consists of subjecting them to a temperature of 4 °C for 15 days. The pre-treated seeds were seeded in unicell cavities in peat-agrolite substrate in a ratio of 1: 2 (volume: volume), then placed in a germination-growing chamber under conditions of 25 °C, 75 % of RH and 14 hours of photoperiod.
From the seedlings obtained (with a percentage of germination between 85 and 95 %), 20 of 6 cm high were selected per species, which were transplanted to a mini-rhizotron system (Climent et al., 2008). These mini-rhizotrons were formed from polyvinyl chloride (PVC) tubes 10 cm in diameter and 35 cm in length, which were cut by the center, resulting in two mini- rhizotrons from each tube (Figure 1).
150 days after transplantation, a destructive analysis was performed with 10 plants per species selected at random. From each of the structures studied, the fresh weight and dry weight were recorded by analytical balance (Ohaus l PA214 mode).
From the root, the specific length (LER) (ratio between root length and root dry weight in cm g-1), density (root dry weight ratio and fresh volume in g cm-3 and the fresh volume (water displacement method in 1 ml graduated pipette), all lateral roots were evaluated for number, length (cm) and diameter (mm) effects, and their classification was based on the main root as The total length (LTRL) was calculated by summing all of them.
After the fresh weight measurements, the seedlings were dried in an oven (Terlabo TE-H35D model) at 60 °C for seven days until reaching constant weight (g) in each section.
The analysis of the radical system was carried out by the ImageJ 1.4 program (Macinstosh). An ANOVA was used by a completely randomized design with the S-pluss package (Tibco Software Inc., 2000) with a P value <0.05 for significance.
Results and Discussion
Results indicate that Pinus michoacana reached significantly higher values in fresh and dry weight of the studied parts compared to P. martinezii and P. pseudostrobus. The growth of the first species was 72 to 97 % in the aerial part and 70 to 140 % in the root. There was no significant difference in these variables between P. martinezii and P. pseudostrobus (Table 1).
PF = Fresh weight; PS = Dry weight; A/R = Aerial part and root rate; ± = Standard error. Different letters indicate significant statistical difference (P < 0.05 and n = 10 individuals per species).
The growth of the three species has not been recorded from the same system. These results suggest that P. pseudostrobus and P. martinezii come from similar sites, as has been observed in other pines (Salazar et al., 1999) and that the survival of these two species could behave in the same way.
In addition, P. michoacana has a greater potential for survival than P. pseudostrobus and P. martinezii, as it has a larger water storage capacity, as indicated by the fresh weight of shoot and root, and incorporates an amount of assimilated carbon as tissues (dry weight) under similar growth conditions. This coincides with the findings by Gómez-Romero et al. (2012) who observed greater survival of P. michoacana plants than P. pseudostrobus plants at a degraded site.
The values of the aerial part / root ratio (A / R) were between 1.58 and 1.96 in all three species. Previous studies have shown that conifers allocate more carbon to build up the area than the root (Levy et al., 2004; Mokany et al., 2006), which agrees with the results of this experiment. This carbon distribution (A / R ratio) coincides with the allometric biomass distribution theory (Niklas and Enquist, 2001) and indicates that all three species come from similar sites in relation to water availability. In this sense, Cregg (1994) observed greater carbon distribution to shoot in Pinus ponderosa Dougl. ex Laws plants. from different locations with high availability of water.
The variables of the root showed no significant difference between P. martinezii and P. pseudostrobus (Table 2), while the difference between these two species and P. michoacana was significant, which is similar to that observed in root weight and the aerial part. Carbon distribution measured through root morphological variables has not been recorded under conditions of sufficient water availability. The specific length of this structure (LER) was different among the species evaluated in this experiment and was greater than 100 % in P. pseudostrobus and P. martinezii in relation to P. michoacana. These results coincide with those of King et al. (1997), who observed a significant difference of LER in two pine species. LER showed an inversely proportional relation with LTRL, LPRL, root density (DR) and root volume (VR). The difference between P. pseudostrobus and P. martinezii in relation to P. michoacana was between 40 and 90 %. The inverse relationship between these variables coincides with previous studies. Ostonen et al. (2007) found plants with lower LER and greater soil exploration capacity. Therefore, P. michoacana could have a better survival compared to the other species for its ability to explore more soil volume because of its lower RSI. Such behavior in these species of conifers does not depend on the total number of lateral roots, but the exploration depends on the length of the lateral roots of the first order.
Species | LER (cm g-1) | LTRL (cm) | LPRL (cm) | DR (g cm-3) | VR (cm3) |
---|---|---|---|---|---|
Pinus pseudostrobus Lindl. | 335.3±22.1 a | 182.9±8.0 b | 1.3±0.08 b | 0.21±0.02 ab | 0.49±0.06 b |
Pinus martinezii E. Larsen | 331.7±43.9 a | 199.3±26.9 b | 1.0±0.09 b | 0.18±0.02 b | 0.56±0.04 b |
Pinus michoacana Martínez | 154.2±15.0 b | 327.9±21.9 a | 1.9±0.17 a | 0.26±0.01 a | 0.83±0.05 a |
LER = Specific root length; LTRL = Total length of lateral roots per plant; LPRL = Average length of lateral roots; DR = Density; VR = Volume of the root. ± = Standard error. Different letters indicate significant statistical difference (P < 0.05 and = 10 individuals per species).
The values of root morphology show a clear difference in the carbon distribution in the three species (Table 3). The length of the main root and the number of first order roots was significantly higher in P. martinezii than in P. pseudostrobus and P. michoacana; of the latter, the length and diameter of the first order lateral roots were also found in P. michoacana in relation to the other two species. The largest diameter of the roots of the first, second and third order was confirmed in P. michoacana and P. pseudostrobus compared to that of P. martinezii. These results of root morphology make evident the variation in carbon distribution among pine species and provide further evidence that the greater survival of P. michoacana could be related to the length and diameter of the lateral roots, followed by P. pseudostrobus and finally P. martinezii.
Pma = Pinus martinezii E. Larsen; Pp = Pinus pseudostrobus Lindl.; Pmi = Pinus michoacana Martínez; ± = Standard error. Different letters indicate significant statistical difference (P < 0.05 and n = 10 individuals per species).
Conclusions
There is variation in the carbon distribution at inter-species level and coincides with the percentage of survival. This relationship was not consistent with variables such as dry weight of aerial part and root, proportion aerial part and root, volume and root length, but other variables such as root specific length (LER), total length of lateral roots, length and Root diameter by root order are parameters with greater accuracy.
Acknowledgements
The authors wish to express their gratitude to Javier Villegas Moreno, Lorena Carreto Montoya and Santos Zepeda Guzmán for their support in this research at the Laboratorio de Interacción Suelo-Planta-Microorganismo of Instituto de Investigaciones Químico-Biológicas de la Universidad Michoacana de San Nicolás de Hidalgo (Soil-Plant-Microorganism Interaction Laboratory of the Institute of Chemical-Biological Research of the Michoacan University of San Nicolás de Hidalgo). To the Comisión Forestal del Estado de Michoacán (COFOM) for the contribution of the seeds of Pinus michoacana and P. pseudostrobus.
REFERENCES
Aranda, I., R. Alía, U. Ortega, Â. K. Dantas and J. Majada. 2010. Intra-specific variability in biomass partitioning and carbon isotopic discrimination under moderate drought stress in seedlings from four Pinus pinaster populations. Trees Genetics and Genomes 6: 169-178. [ Links ]
Bloom, A. J., F. S. Chapin and H. A. Mooney. 1985. Resource limitation in plants- an economic analogy. Annual Review of Ecology & Systematics 16: 363-392. [ Links ]
Chambel, M. R., J. Climent and R. Alía. 2007. Divergence among species and populations of Mediterranean pines in biomass allocation of seedlings grown under two water regimes. Annuals of Forest Sciences 64: 87-97. [ Links ]
Climent, J., J. Alonso and L. Gil. 2008. Root restriction hindered early allometric differentiation between seedlings of two provenances of Canary Island Pine. Silvae Genetica 57: 187-193. [ Links ]
Cregg, B. M. 1994. Carbon allocation, gas exchange, and needle morphology of Pinus ponderosa genotypes known to differ in growth and survival under imposed drought. Tree Physiology 14: 883-898. [ Links ]
Friend, A. L., M. D. Coleman and J. G. Isebrands. 1994. Carbon allocation to root and shoot systems of woody plants. In: Davis, T.D. and B. E. Haissig. Biology and adventitious root formation. Plenum Press. New York, NY, USA. pp. 245-273. [ Links ]
Gómez-Romero, M., J. C. Soto-Correa, J. A. Blanco-García, C. Sáenz-Romero, J. Villegas y R. Lindig-Cisneros 2012. Estudio de especies de pino para restauración de sitios degradados. Agrociencia 46 (8):795-807. [ Links ]
Guarnaschelli, A. B., J. H. Lemcoff, P. Prystupa and S. O. Basci. 2003. Responses to drought preconditioning in Eucalyptus globules Labill. Provenances. Trees 17: 501-509. [ Links ]
King, J. S., R. B. Thomas and B. R. Strain. 1997. Morphology and tissue quality of seedling root systems of Pinus taeda and Pinus ponderosa as affected by varying CO2, temperature, and nitrogen. Plant and Soil 195 (1): 107-119. [ Links ]
Levy, P. E., S. E. Hale and B. C. Nicoll. 2004. Biomass expansion factors and root:shoot ratios for coniferous tree species in Great Britain. Forestry 77: 421-430. [ Links ]
Markesteijn, L. and L. Poorter. 2009. Seedlings root morphology and biomass allocation of 62 tropical tree species in relation to drought-and shade-tolerance. Journal of Ecology 97: 311-325. [ Links ]
Mokany, K., R. J. Raison and A. S. Prokushkin. 2006. Critical analysis of root: shoot ratios in terrestrial biomes. Global Change Biology 12: 84-96. [ Links ]
Morales H., J. 2014. Desarrollo de estrategias de propagación en vivero para la conservación de Pinus martinezii Larsen. Tesis Maestría. Facultad de Ingeniería en Tecnología de la Madera, Universidad Michoacana de San Nicolás de Hidalgo. Morelia, Michoacán, México. 88 p. [ Links ]
Muñoz F., H. J., G. Orozco G., V. M. Coria A., J. J. García S., Y. Y. Muñoz V. y G. S. Cruz. 2011. Evaluación de Pinus pseudostrobus Lindl. y Pinus greggi Engelm. con dos densidades de plantación en Michoacán México. Foresta Veracruzana 13 (1): 29-35. [ Links ]
Niklas, K. J. and B. J. Enquist. 2001. Invariant scaling relationships for interspecific plant biomass production rates and body size. Proceedings of the National Academy of Sciences 98 (5):2922-2927. [ Links ]
Ostonen, I., Ü. Püttsepp, C. Biel, O. Alberton, M. R. Bakker, K. Lõhmus, H. Majdi, D. Metcalfe, A. F. M. Olsthoorn, A. Pronk, E. Vanguelova, M. Weih and I. Brunner. 2007. Specific root length as an indicator of environmental change. Plant Biosystems 141 (3): 426-442. [ Links ]
Paz, H. 2003. Root/Shoot Allocation and root architecture in seedlings: variation among forest sites, microhabitats, and ecological groups. Biotropica 35 (3): 318-332. [ Links ]
Salazar G. J. G., J. J. Vargas H., J. Jasso M., J. D. Molina G., C. Ramírez H. y J. López U. 1999. Variación en el patrón de crecimiento en altura de cuatro especies de Pinus en edades tempranas. Madera y Bosques 5 (2): 19-34. [ Links ]
South, D. B. 2000. Planting morphologically improved pine seedlings to increase survival and growth. Forestry and Wildlife Research Series Num. 1. Auburn University. Auburn, AL, USA. 12 p. [ Links ]
Received: February 08, 2016; Accepted: October 29, 2016