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Revista mexicana de ciencias agrícolas

versão impressa ISSN 2007-0934

Rev. Mex. Cienc. Agríc vol.7 no.1 Texcoco Jan./Fev. 2016



Mechanical damage due to compression in tuberose (Polianthes tuberosa)

Gloria Alicia Pérez-Arias1  § 

Irán Alia-Tejacal1 

María Teresa Colinas-León2 

Luis Alonso Valdez Aguilar3 

1Universidad Autónoma del Estado de Morelos. Avenida Universidad Núm. 1001. Cuernavaca, Morelos. C. P. 62209. 7771626383. (

2Universidad Autónoma Chapingo-Departamento de Fitotecnia. 015959517682. ( Carretera México-Texcoco, km 38.5. Chapingo, Estado de México. C. P. 56230.

3Universidad Autónoma Agraria Antonio Narro-Departamento de Horticultura. Calzada Antonio Narro 1923. Saltillo, Coahuila, C. P. 25315. (


‘Perla’ tuberose (Polianthes tuberosa L.) sprigs were harvested with two open flower buds. They were submitted to compression treatments with 70, 140, and 210 Pa; subsequently, a 20% sucrose pulse solution treatment was applied alongside an Ethylbloc® treatment (1 bag with 0.014% active ingredient (1-MCP)) for 24 h. Some physiological changes were evaluated (CO2 and ethylene production indices, water consumption, and relative fresh weight) in the flower vase over the course of six days. Furthermore, two groups of tuberose sprigs were formed, compression not being applied to either. The first group received pulse solution whereas the second group did not, the latter being the control group. The tuberose sprigs showed increases in the respiration speed and ethylene production similar to climacteric flowers. The sprigs subjected to compression above 70 Pa showed between 31 and 47% greater respiration speed and between 26 and 29% greater ethylene production compared to the sprigs that received the control treatment. The percentage for the initial weight (7 and 11.5%) and water consumption (21 and 71%) was significantly greater in the flowers subjected to compression compared to the control group. It can be concluded then that the mechanical damage due to compression increases ethylene production and respiration speed, and also increases the percentage of water consumption and relative weight. These factors can influence the abscission and opening of the flowers of the tuberose sprigs.

Keywords: Polianthes tuberosa; ethylene; respiration; water consumption


Se cosecharon espigas de nardo (Polianthes tuberosa L.) ‘Perla’ con dos flores basales abiertas, fueron sometidas a tratamientos de compresión con 70, 140 y 210 Pa; posteriormente se les aplicó un tratamiento de solución pulso de sacarosa al 20% junto con un tratamiento de Ethylbloc® (1 bolsa con 0.014% de ingrediente activo (1-MCP)) por 24 h y se evaluaron algunos cambios fisiológicos (tasa de producción de CO2, etileno, consumo de agua y peso fresco relativo) en florero durante seis días. Adicionalmente se formaron dos grupos de espigas de nardo, en ambos no se aplicó la compresión, el primer grupo recibió solución pulso y el segundo no se aplicó solución pulso, este último fue considerado el testigo. Las espigas de nardo mostraron incrementos en la velocidad de respiración y producción de etileno similares a flores climatéricas. Las espigas sometidas a compresión superior a 70 Pa mostraron entre 31 y 47% mayor velocidad de respiración y entre 26 y 29% mayor producción de etileno comparadas con las que recibieron el tratamiento testigo. El porcentaje de peso inicial (7 y 11.5%) y consumo de agua (21 y 71%) fue significativamente mayor en las flores sometidas a compresión, con respecto al testigo. Se concluye que el daño mecánico por compresión incrementa la producción de etileno y velocidad de respiración, así como incremento en el consumo de agua peso y porcentaje de peso relativo. Estos factores pueden influenciar la abscisión y apertura de flores de la espiga de nardo.

Palabras clave: Polianthes tuberosa; consumo de agua; etileno; respiración


Tuberose (Polianthes tuberosa L.) is an herbaceous perennial plant belonging to the Agavaceae family (Dole and Wilkins, 2005). It is an ornamental bulbous plant native to Mexico which was dispersed around the world in the XVI century (Barba-González et al., 2012). It has garnered popularity as a cut flower in various countries and it is commercially grown in Kenya, Iran, India, and Mexico for export to countries such as the United States, Europe, and Japan (Kumar et al., 2010; Hassanpour et al., 2011; Murrithi et al., 2011).

In Mexico, the bulk of the production can be found in the states of Morelos, Mexico, Guerrero, Veracruz, and Puebla, where 276 hectares of this species are cultivated generating 6.4 million Mexican pesos (MXN) in yearly sales (SIAP, 2014). In the state of Morelos, tuberose is among the main types of cut flowers grown alongside the rose (Rosa sp.) and gladiolus (Gladiolus grandifloras L.) (Cabrera and Orozco, 2003; SIAP, 2014). 171 hectares are reported to be dedicated to the cultivation of this cut flower and as such Morelos generates 62% of the national production (SIAP, 2014).

The bulb of the tuberose is pyriform and the stem reaches up to 1.50 m in height. It is simple, with ribbon-shaped leaves and the stems are reduced to scales (Toledo, 2003). The inflorescence of the tuberose has between 10 and 20 pairs of flowers, which open acropetally. The tuberose has cultivars with simple or double flowers, both white in color (Barba-González et al., 2012). In the localities of Morelos where tuberose is cultivated, the main variety is the double or better known as the ‘Perla’ (Vázquez, 2004).

The harvest index for tuberose is when two or three flowers from the basal part have opened (Dole and Wilkins, 2005). Each flower survives approximately 3 days, with the average life of the inflorescence being between 7 and 10 days (Kumar and Kumar, 2013). Less than 50% of the flowers open after the harvest and generally fall off after various days (Wahitaka et al., 2001). Because of this, pulse solutions and preservatives have been evaluated in order to improve the post-harvest life of this cut flower. It has been determined that sucrose pulse solution (4 - 20%) alone or containing hydroxyquinoline citrate (200 mg L-1), citric acid (2%), silver nitrate (20 mg L-1), silver thiosulphate (1 to 2 mM) or sodium thiosulphate, increases the post-harvest life (10 and 20 days) and the flowering period (60 to 88%) of tuberose (Wahitaka et al., 2001; Hutchinson et al., 2003; Choudury and Barooah, 2011). In a similar fashion, it has also been found that the application in preserving solutions of cobalt chloride (300 mg L-1), benzyladenine (100 mg L-1), humic acids (25 mg L-1) and silver nanoparticles (0.5 - 1 mg L-1) significantly improves the post-harvest life of tuberose (Hassanpour et al., 2011; Mohammadi et al., 2012 a and b; Amani et al., 2013). For transport and storage, a temperature of 0 to 5 ºC is recommended (Armitage and Laushman, 2003; Kumar et al., 2010).

In Morelos, when the flowers are harvested they are generally picked and packaged in rolls of 100 stacked stems and are transported to the Central de Abastos in Distrito Federal and to the Flower Market in Tenancingo, State of Mexico (Toledo, 2003). In these short transport distances, a factor that could affect the post-harvest life is the stress by mechanical damage due to compression. The extreme packaging, rough handling and inappropriate care conditions in the market result in low quality. The compression, breakage of the stems, folding of the leaves, abrasion and vibration of the petals are aspects not often studied and which generate a shorter post-harvest life.

Considering the aforementioned, this work evaluated the effect of compression on some physiological and physical variables of tuberose ‘Perla’ sprigs, as an initial study in order to determine its negative impacts.

Materials and methods

Plant material

Tuberose stems harvested in Morelos were collected from a commercial garden in Cuauchichinola, Mazatepec, Morelos; the locality has a warm sub-humid climate (Awo) and coordinates 18º 38’ 58.12’’ north latitude, 99º 22’ 49.62’’ west longitude, with an altitude of 910 m (Ornelas et al., 1990). The stems were harvested in accordance to the harvest index of the producer, i.e. when at least two flowers were opened. The stems were harvested at 8:00 am and transported to the Agricultural Production Laboratory of the Faculty of Agricultural Sciences at the Universidad Autónoma del Estado de Morelos, which has a semi-warm climate A(C) and coordinates 18º 58’ 53.73’’ north latitude, 99º 13’ 58.43’’ west longitude, and an altitude of 1 874 m (Ornelas et al., 1990). They were immediately placed in potable water and were left at room temperature (22 ± 2 ºC; 60% RH) for two hours.

Treatment design

Five groups were made each comprised of 18 tuberose stems cut to 60 cm; the groups were placed on the ground between two pieces of cardboard and had sandbags placed on top of them in order to produce a pressure of 70, 140, and 210 Pa, which simulates the compression caused when being transported from Morelos to Mexico City. In addition, there were two groups that did not have compression applied to them. The compression treatment was maintained for three hours, simulating the transport time between the place of harvest and the place of retail.

Following the compression treatment, the flower groups were placed in a 20% sucrose pulse solution in hermetic plastic containers for 24 hours, alongside four bags of Ethylbloc® [(2.5 g bag with 0.014% active ingredient, 1-methylcyclopropene (1-MCP)]. The pulse solution was not applied to one group of tuberose stems. The five groups were maintained as follows: 1) tuberose stems without compression and without pulse solution (control); 2) tuberose stems without compression and with pulse solution; 3) tuberose stems with compression of 70 Pa and pulse solution; 4) tuberose stems with compression of 140 Pa and pulse solution; and, 5) tuberose stems with compression of 210 Pa and pulse solution. After applying the treatments to the tuberose stems, they were kept in 1 L plastic test tubes and the ethylene and CO2 production, water consumption, and relative fresh weight were evaluated on a daily basis. The evaluations were carried out at a room temperature of 22 ± 2 ºC, 60% RH.

Evaluated variables

Ethylene and CO2 production. A tuberose inflorescence was placed daily in a plastic container of known volume (1.8 L) and sealed. After 1 hour, 6 mL of the head space were taken using a syringe and were injected in Vacuntainer® tubes of the same capacity where they were kept until their analysis. The concentration of gasses was determined using a gas chromatograph Varian® (Varian Star 3400CX, USA). 1 mL of the gas stored in the Vacuntainer® was taken, which subsequently was injected into the gas chromatograph. CO2 (460 mg L-1) and ethylene (100 mg L-1) standards were used (INFRA®) as reference in order to calculate the ethylene and CO2 production. The column temperatures of the injector and the detector were 80, 150, and 170 ºC, respectively. Helium was used as a carrier gas with a flow of 32.3 mL min-1. The production of CO2 in mL kg-1h-1 and of ethylene in μL kg-1h-1 were reported per sprig.

Water consumption. 250 ml of potable water was placed in each test tube with the remaining water being measured on a daily basis. Each day, 250 mL were placed once more for subsequent evaluation.

Relative fresh weight. When daily evaluating the water consumption, the weight of the floral stem was quantified until its vase life was considered finished, which was when 50% of the flowers of each sprig were dead, approximately in a period of six days. It was reported as a weight percentage relative to the initial mass of the evaluation in the vase, which was considered 100%.

Data analysis

An entirely random experimental design was utilized. The experimental unit was a sprig and there were six copies. The data obtained was analyzed through a variance and comparison analysis of measurements by means of the least significant difference (p≤ 0.05) method when significant differences were detected with the software SAS® V.9.1 (Castillo, 2011).

Results and discussion

Significant differences were observed due to the effect of compression on respiration, ethylene production, relative weight percentage, and water consumption (Table 1).

Table 1. Effect of different levels of compression on some physiological variables of tuberose. Average of all the samples. 

Tratamiento Consumo de agua (mL de agua espiga -1 ) Porcentaje de peso relativo (%) Respiración (mL de CO 2 kg -1 h -1 ) Etileno (μL kg -1 h -1 )
Testigo 8.5 Zb 108.7 c 32.7 c 206.6 b
0 Pa†† 12.8 a 111.0 bc 38.9 b 205.5b
70 Pa 12.5 a 113.8 ab 43.1 b 209.3 ba
140 Pa 14.3 a 117.6 a 48.3 a 260.5 a
210 Pa 13.7 a 116.2 ab 48.0 a 267.5 a
DMS 3.0 5.0 4.7 41.5
CV (%) 13.1 9.5 12.4 17.6


The respiration of the sprigs used as a control at the start of the evaluation presented a phase similar to a pre-climacteric period with values of 31.3 mL kg-1h-1 of CO2. Subsequently, a sharp decrease of up to 22.7 mL kg-1h-1 was observed, which later increased to a maximum of 46.3 mL kg-1h-1 (climacteric). Finally a post-climacteric phase was observed that was defined by decreasing respiration to 31.5 mL kg-1h-1 (Figure 1 A); this behavior is similar to what was reported in a previous study (Pérez-Arias et al., 2014). The application of the pulse solution increased the respiration speed (Table 1, Figures 1 B, C, D, and E) due to the sugars provided, which were used as a substrate for respiration, preventing a rapid decline and senescence (Reid, 2009).

Figure 1. Initial respiration speed in tuberose sprigs in vases after being subjected to various intensities of compression. A) control; B) without compression; C) compression of 70 Pa; D) compression of 140 Pa; and, E) compression of 210 Pa. Each point represents the measurement of 6 observations and its standard error. 

The respiration of the stems increased significantly when mechanical compression was applied (Table 1; Figure 1 A). Thus, in the flowers subjected to compression of 140 and 210 Pa, the respiration speed was kept between 54 and 57 mL kg-1h-1, without decreasing from 40 mL kg-1h-1 (Figure 1 D and E). The increase in respiration is attributed to the damage caused by compression, due to the fact that in damaged tissue oxygen is diffused more quickly in the interior of the cells and its metabolic activity increases (Watada et al., 1996). Mechanical damage in flowers must be avoided at all costs, as it causes high respiration, which in turn reduces its useful life (Reid, 2009).

Ethylene production

Ethylene production showed a decrease during the first three days and subsequently increased at a constant rate from the fourth to the sixth day of evaluation (Figure 2 A); similar behavior was observed in sprigs subject to pulse solution but without being subjected to any compression (Figure 2 B). In sprigs subjected to mechanical compression of 70, 140, and 210 Pa, the pre-climacteric, climacteric, and post-climacteric stages were observed (Figures 1 C, D, and E), in addition to a significantly greater ethylene production (Table 1).

Figure 2. Ethylene production in tuberose sprigs in vases after being subjected to various intensities of compression. A) control; B) without compression; C) compression of 70 Pa; D) compression of 140 Pa; and, E) compression of 210 Pa. Each point represents the measurement of 6 observations and its standard error. 

The results suggest that the climacteric behavior was not fully observed in the control sprigs and the sprigs subjected to pulse solution without compression (Figure 2 A and B); however, in the flowers subjected to mechanical damage, the climacteric was well defined and with greater intensity (Figure 2 C, D, and E). The mechanical damage induces a general response from the plant through the activation of the ACC synthase and ACC oxidase (Kakarut and Hubert, 2003), and consequently a greater ethylene production is presented. Waithaka et al. (2001) indicates that the exogenous ethylene applied to the tuberose sprigs causes the abscission of open and closed flowers in approximately four days.

Naidu and Reid (1989) reported that ethylene inhibits the opening of flowers on tuberose sprigs; however, it was concluded that in spite of these negative effects, ethylene is not important in the senescence of flowers. In this study, the control sprigs and those only subjected to pulse solution showed statistical similarities (Table 1), indicating that the application of Ethylbloc® did not prompt a decrease in ethylene production. This result is different from what was reported in orchids species, where the application of Ethylbloc® decreased ethylene production (Uthaichay et al., 2007). The results obtained suggest that the compression increased ethylene production.

Relative weight

The flowers of the control treatment increased the relative weight by 115% by the third day of evaluation, subsequently decreasing at a constant rate until reaching values of 107% on the sixth day (Figure 3 A). The increase in the relative weight is due to the fact that the tuberose sprigs rehydrate during the post-harvest handling. The sprigs subjected to pulse solution but without mechanical compression reached a maximum of 119% (Figure 3 B), whereas the sprigs subjected to pulse solution and mechanical compression of 70, 140, and 210 Pa showed maximum values of 123, 128, and 126.4%, respectively, (Figure 2 C-E) and were the ones that had a greater increase in the relative weight (Table 1).

Figure 3. Initial weight percentage of tuberose sprigs in vases after being subjected to various intensities of compression. A) control; B) without compression; C) compression of 70 Pa; D) compression of 140 Pa; and E) compression of 210 Pa. Each point represents the measurement of 6 observations and its standard error. 

This suggests that the pulse solution favors a greater increase in the relative weight percentage, as indicated by Var and Barad (2007) who determined that the tuberose flowers subjected to pulse solution with sucrose maintain a greater water consumption and a lesser weight loss, which directly relates to the relative fresh weight.

Water consumption

The control sprigs were the ones that absorbed the least amount of water (Table 1), with the maximum water consumption being on the third evaluation day with values of 14 mL per sprig. The sprigs subjected to pulse solution with mechanical compression of 0, 70, and 140 Pa showed the maximum water absorption on the third evaluation day with 21, 19, and 24 mL per sprig, respectively (data not shown), whereas for sprigs subjected to 210 Pa of pressure, the maximum absorption was obtained on the fifth evaluation day with 17.3 mL per sprig (data not shown). This coincides with data by Varu and Barad (2007) where they mention that the tuberose flowers to which pulse solution with sucrose is applied maintain a greater water consumption and a lesser weight loss due to the fact that sugar prevents hydric stress and maintains the metabolic processes.

The greater water consumption and relative fresh weight in tuberose inflorescences on which greater mechanical compression was applied (Table 1; Figure 3 C-D) are probably due to having caused mechanical damage on the epidermis of the inflorescences and therefore having a greater water leak, which was replaced by the inflorescences with water from the vase. Van Doorn (2012) mentions that in cut flowers placed in a vase, the water consumption was less than the residual loss of the stomas and cuticular perspiration; this latter could be increased by compression treatments.


The tuberose sprigs show a climacteric behavior with significant increases in respiration and ethylene production during the post-harvest. Mechanical compression of more than 70 Pa caused greater respiration and ethylene production, as well as greater relative water weight and water consumption.

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Received: August 2015; Accepted: January 2016

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