Seasonal variation of transpiration of Nance (Byrsonima crassifolia L.) HBK selections under subtropical conditions climate: basic study

R. Medina-Torres1*; S. Salazar-García2; M. E. Ibarra-Estrada2

1. Universidad Autónoma de Nayarit, Unidad Académica de Agricultura, Km. 9 Carretera Tepic-Compostela, Xalisco, Nayarit, C.P. 63780, México., Universidad Autónoma de Nayarit, Universidad Autónoma de Nayarit, Unidad Académica de Agricultura,

<state>Nayarit</state>
, Mexico , 2. Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias. Campo Experimental Santiago Ixcuintla. Apdo. Postal 100, Santiago Ixcuintla, Nayarit, C.P. 63300, México., Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, Campo Experimental Santiago Ixcuintla,
<state>Nayarit</state>
, Mexico

Correspondence: *. Corresponding author: Raul Medina-Torres, Universidad Autónoma de Nayarit, Unidad Académica de Agricultura, Km. 9 Carretera Tepic-Compostela, Xalisco, Nayarit, C.P. 63780, México. Phone: +52(311)211 1163. E-mail: E-mail:


Abstract

The objective of this study was to determine the variation of transpiration (E) during the drought stress period and its relation with the phenological phases of nance [Byrsonima crassifolia (L.) H.B.K.]. Seven measurements of E were made in four nanche selections from March 12th to June 24th 2013 (drought season), plus an additional measurement in the rainy season (September 03rd 2013). The four nanche selections showed a similar distribution pattern of E during the evaluation period. These selections showed a the decrease of E parallel to the soil moisture deficit until full spring (1.15 mmol H2O cm-2 s-1); however, E gradually increased even under severe drought stress, which occurred at the end of spring. Afterwards, E increased to reach a maximum during the rainy season (3.64 mmol H2O cm-2 s-1), when the soil was saturated with moisture to finally decline at the end of winter (2.44 mmol H2O cm-2 s-1). The phenological phases of the nance occurred at the same dates and with similar intensity to those previously reported by the authors of the present study and not altered by water stress therefore ratifying B. crassifolia as tolerant to water stress.

Received: 2017 March 26; Accepted: 2017 October 3

revbio. 2020 May 29; 5: e320
doi: 10.15741/revbio.05.e320

Keywords: Key words: Byrsonima crassifolia, drougth stress, phenology.

Introduction

Nance [Byrsonima crassifolia (L.) HBK] belongs to the Malpighiaceae family; it is a species of importance as a regional fruit in Mexico and South America. In Mexico, 1,517.75 ha of nance are reported, with an average yield of 4.94 t ha-1; the main state producers are Guerrero (666 ha), Michoacan (235.5), Nayarit (222 ha), and Veracruz (127 ha) (SIAP, 2017). In Nayarit, nance plantations are located in the warm climate zones where savannah-type vegetation predominates, mainly in the municipalities of Ruiz, Huajicori, Tepic, Santiago Ixcuintla, and Compostela. The main harvest is from July to October, although in irrigated orchards, it is harvested most of the year (Medina-Torres et al., 2004). In Nayarit, three floral flushes are present during the year, known as fall flush, spring flush, and summer flush. These flowerings produce harvest of fruit in spring, summer, and winter, respectively, although the greater volume of harvest is obtained in summer (Medina-Torres et al., 2012).

In Mexico, nance is associated to the deciduous rain forest, sub-deciduous, sub-adeciduate and perennial; xerophilous brushwood and with forests of pine and oak (León, 2000). It tolerates different types of soils, preferably regosol, vertisol, cambisol, and rendzina (Martínez et al., 2008). In its natural habitat, it can endure soils with a rapid drainage or with deficient drainage that become flooded in humid seasons and dried in dry seasons (CNF, 2005). The tree has a tolerance to drought of a magnitude between medium and high; also, it adapts to a wide range of environments, like poor soils, shallow, compact, and stony (Geilfus, 1994).

Goldstein et al., (1989) compared the exchange of gases in two species of evergreen trees (B. crassifolia and Curatella americana) and two deciduous species (Genipa caruto and Cochlospermum vitifoluim) and observed that the evergreen species showed greater rates of water loss through transpiration than deciduous; differences in the transpiration rates were found, and that the minimum potentials of water were not significantly different in both groups of species, suggesting a high efficiency of water transport in the evergreen species.

Solar radiation, temperature, atmospheric precipitation, humidity, and atmospheric CO2 are key environmental factors that act over the processes that occur in the ecosystems. From these, changes in temperature, water availability, and atmospheric CO2 levels will be fixed to changes in the next 100 years due to climate change (Watson et al., 1996).

For the above, the objective was to determine the behavior of transpiration rate (E) in nance selections cultivated without irrigation, with measurements of E in contrasting conditions of soil moisture, particularly during the period of soil water deficit, and in different phenological phases of this fruit tree.

Materials and Methods

Experimental conditions. The study was performed in an orchard of nance selections, located in Xalisco, Nayarit, at 21° 26’ NL and 104° 55’ WL, at an altitude of 960 meters above sea level, with a semi-warm climate (sub-tropical sub-humid), the warmest of the mild weathers (Garcia-Amaro, 1988), with annual pluvial precipitation greater than 1,300 mm, whose month of maximum rain is July (370 to 380 mm) and minimum rain is May (lower than 30mm). The medium annual thermic regime varies from 20 to 29 °C. The warmest months occur between June and September with an average of 24 °C, and the coldest months occur between December and January with an average of 16 °C.

The trees from the nance selections were originated from seeds and were planted to 5 by 3 m between lines and between plants, respectively; which, according to their characteristics of color and flavor, they are locally called “Amarillo Dulce”, “Amarillo Acido”, “Ácido Chico” and “Mejorado”.

Evaluated variables. Transpiration measurements were done in four trees by selection, when these were five years old. In each tree, four equidistant shoots were randomly marked. A diffusion porometer LI-1600 (LI.COR, Lincoln NE, USA) was used; it measures the stomatal conductance as an opening and ending index of the stomas, and determines the flow of gases or the diffusion done through them. In the marked leaves, the transpiration rate (E, mmol H2O m-2 s-1), temperature of the leaf (LT, °C), relative humidity of air close to the leaf (LRH, %), stomatic conductance (gs, cm-1 s-1), active photosynthetic radiation (PAR, µmol m-2 s-1) and resistance to diffusion (r, s-1 cm-1) were determined. The rate of E and the environmental climatological variables were related to the phenological state of nance on each date of porometry measurements.

The measurements were done on the fifth and sixth leaf completely expanded from the last seasonal vegetative growth of fall 2012. Eight measurements of E were done in the year 2013, seven during the period of deficit of water in the experimental site: one at the end of winter (March 12th), two at the beginning of spring (April 9th and 30th), two in mid-spring (May 14th and 28th), one at the end of spring (June 11th), one at the beginning of summer (June 24th), and one more in mid-summer (September 3rd) when rain period has already been established, with the objective of observing the rate of E on saturated leaf. All the measurements were done at 10:00 am on the same marked leaf. On each one of the dates above, and on each selection of nance, a total humidity determination of soil was done (HS in %) through the gravimetric method (Aguilera and Martinez, 1990) at two depths: 0 to 30 cm and 30 to 60 cm, taking the samples at one meter of distance from the trunk to the tree. Only E and the variables associated to it were analyzed within three dates of measurements, taken as representatives of each season during the period of measurements: end of winter (March 12th), mid-spring (May 14th) and start of summer (June 24th). The environmental data of temperature, relative humidity, evaporation, and pluvial precipitation were obtained from the meteorological station located in Tepic, Nayarit (21° 31’ NL and 104° 53’ WL) (Table 1). As an additional data, the density of the stomas per mm2 was determined through the impression technique described by Larque-Saavedra and Trejo (1990)).

Table 1.

Seasonal variation of transpiration (mmol H2O m-2 s-1) of nance selections during the wáter stress period and the rainy season (middle of the summer), 2013.


End of
winter
Beginning
of spring
End of
spring
Beginning
of summer
Middle of
summer
Selection March 12th April 9th April 30th May 14 th May 28 th June 11 th June 24 th September 3rd
Amarillo Dulce 2.49a 1.60a 1.18a 1.35a 1.83c 3.03a 3.88a 3.97ab
Amarillo Ácido 2.43a 1.21bc 1.11a 1.15b 1.81c 2.94ab 3.55b 3.85bc
Ácido Chico 2.40a 1.27b 1.15a 1.11bc 2.17a 2.78bc 3.55b 3.75c
Mejorado 2.48a 1.15c 1.05a 1.00c 2.00b 2.76c 3.57b 4.07a

TFN6Means with the same letter in columns are not statistically different (Tukey, 0.05).


Statistical analysis. A completely random design was used for analysis of variance and means test. The statistical analysis was done in three sections: 1) Analysis of variance and means test (Tukey, p ≤ 0.05) on the transpiration rate occurred during the period of measurements; 2) analysis of variance and means test (Tukey, p ≤ 0.05) on the transpiration rate and its associated variables (PAR, gs, r, TH, HRH) among the nance selections, but only on the measurements at the end of winter (March 12th), middle of spring (May 14th) and start of summer (June 24th); and 3) test of multiple lineal correlation of the variables of porometry with the original data of all the dates of measurements. The statistical analyses were done using the statistical package SAS (SAS Institute Inc., 1999).

Results and Discussion

Seasonal variation of the transpiration rate (E). In general, the average transpiration rate among the nance selections were 2.3 mmol H2O cm-2 s-1 (p ≤ 0.01, R2 = 0.98, CV = 7.11 %) during the period of measurements, and it followed a kinetic corresponding to a sinusoidal curve which reached its highest values (3.91 mmol H2O cm-2 s-1) in winter and summer, and the lowest (1.1 mmol H2O cm-2 s-1) in spring (Figure 1).


[Figure ID: f2] Figure 1.

Transpiration rate (E) of the Nance and soil moisture (SM, 30-60 cm) for 2013. CI = Winter harvest; ICP = starst Spring harvest; FP = flower Spring flush; TCP = ends Spring harvest; TFP = ends Spring floral flush.


On the seasonal variation of E in all of the nance selections (Table 1), the lowest rates were observed in spring during the period from April 9th to June 11th, season of progressive deficit of humidity in soil to a depth of 0 to 30cm (11.51 to 6.86 %) and 30 to 60 cm (15.08 to 10.77 %), relative humidity of the environment from 72 to 80 %, and warmer environmental temperature (22.2 to 23.9 °C) having fluctuations of the evaporation from 6.08 to 6.35 mm and 0 pluvial precipitation (Table 2). In this season, phenological phases of flowering and growth of the nance fruit presented simultaneously.

Table 2.

Mean transpiration rate (E), soil moisture (SM), enviromental temperature (ET), relative humidity (RH), evaporation (EV), and rainfall (PP), according to measurement day, 2013.


Date E
(µmol cm-2 s-1)
SM
(0-30 cm)
HS
(30-60 cm)
ETz
(°C)
RH
(%)
EV
(mm)
PP
(mm)
Mar 12th 2.44 13.05 16.23 19.6 85 4.82 0
Apr 09th 1.29 11.51 15.08 22.5 72 6.08 0
Apr 30th 1.12 8.05 13.90 22.5 47 7.99 0
May 14th 1.15 7.10 12.18 24.4 51 8.76 0
May 28th 1.95 6.47 11.49 23.9 76 6.68 0
June 11th 2.88 6.86 10.77 23.0 80 6.35 0
June 24th 3.64 4.98 10.02 25.2 82 5.44 0
Sept 03rd 3.91 40.97 52.80 23.9 87 6.31 39.6

TFN7zSource: Comisión Nacional del Agua, Estación Tepic, Nayarit.


The highest rate of E was present at the end of summer (September 3rd) (3.91 mmol H2O cm-2 s-1) when the relative humidity and environmental temperature were high (87 % and 23.9 °C), respectively). In this season, generally, the most abundant crop shows up. The aforementioned allows to infer that E was influenced the most by the phenological phases, the characteristics of the leave and the climate changes, than by the edaphic humidity among the nance selections.

Rate of E at the end of winter. Significant differences were not found among the nance selections for E on the measure from March 12th in none of the variables of porometry associated to E. A rate of transpiration was observed among the nance selections from 2.43 mmol H2O cm-2 s-1, while the relative humidity of the leave was 48.07 % and its temperature was 30.35 °C (Table 3).

Table 3.

Photosynthetic active radiation (PAR), leaf relative humidity (LRH), leaf temperature (LT), stomatal conductance (gs), transpiration rate (E), and resistance to vapor diffusion (r) of Nance selections in the end of winter measurement (March 12th 2013).


Selection PAR
(µmol m-2 s-1)
LRH
(%)
LT
(ºC)
gs
(cm-1 s-1)
E
(µmol H2O cm-2 s-1)
r
(s-1 cm-1)
Amarillo Dulce 1769.4a 51.27a 31.38a 0.02156a 2.49a 47.575a
Amarillo Ácido 1816.3a 49.55a 29.46a 0.02180a 2.43a 46.063a
Ácido Chico 1819.4a 48.04a 30.47a 0.02240a 2.40a 45.169a
Mejorado 1773.1a 47.43a 30.11a 0.02224a 2.44a 45.100a
Average 1794.5 48.07 30.35 0.022 2.4396 45.98
Pr>F 0.1578 0.2238 0.0006 0.7509 0.6959 0.4721
CV (%) 4.48 11.42 4.05 11.11 8.99 10.87

TFN8Means with the same letter in columns are not statistically different (Tukey, 0.05). CV = Coefficient of variation.


The four nance selections followed the same transpiration pattern (Figure 1); in the same dry season, when the average temperature during March was 19.6 °C, no rain, relative humidity at 85 %, soil humidity (30 a 60 cm) at 16.23 % and evaporation at 4.82 mm (Table 2). Statistical differences on the transpiration rate among the studied nance selections were not found at the end of winter (Table 3). The averages in transpiration ended up being low (2.40 to 2.49 mmol H2O m-2 s-1), in this seaon the measurement was done when the trees were at the beginning of winter harvest (WH) coming from the fall flush of flowering (Figure 1).

E rate during spring season. This period included five dates of measurement (April 9th and 30th, May 14th and 28th, and June 11th), where the lower transpiration rates presented (Table 1). Starting from the measurement on May 14th, a noticeable increase on the transpiration rate was observed until the beginning of summer, nonetheless, the low percentage of soil humidity down to a depth of 0 to 30 cm and 30 to 60 cm, which occurred when the maximum deficit of humidity presented (June 24th) (Table 2).

In full spring (May 14th), an average transpiration rate of the selections of nanche of 1.14 mmol H2O m-2 s-1 was observed, when the average relative humidity of the leaf was at 25.51 %, and the temperature of the leaf was 31.76 °C. The selections Amarillo Dulce and Amarillo Acido showed the highest transpiration rates. In relation to the variables associated to E, it was observed that at low E rates resistance to diffusion (r) decreased, the stomatic conductance (gs) increased and the humidity of the leaf decreased (Table 4).

Table 4.

Photosynthetic active radiation (PAR), leaf relative humidity (LRH), leaf temperature (LT), stomatal conductance (gs), transpiration rate (E), and resistance to vapor diffusion (r) of Nance selections in the end full spring measurement (May 14th 2013).


Selection PAR
(µmol m-2 s-1)
LRH
(%)
LT
(ºC)
gs
(cm-1 s-1)
E
(µmol H2O cm-2 s-1)
r
(s-1 cm-1)
Amarillo Dulce 1354.4b 30.78a 30.24b 0.03877c 1.3472a 26.363a
Amarillo Ácido 1455.0ab 24.83b 31.90a 0.04542bc 1.1542b 22.494b
Ácido Chico 1463.1a 24.89b 32.38a 0.04832ab 1.1056bc 21.388bc
Mejorado 1541.9a 21.56b 32.52a 0.05363a 0.9889c 18.988c
Media 1453.6 25.51 31.76 0.0465 1.1490 22.310
Pr>F 0.0002 0.0002 0.0001 0.0001 0.0001 0.0001
CV (%) 7.63 17.76 3.78 16.35 14.90 15.51

TFN9Means with the same letter in columns are not statistically different (Tukey, 0.05). CV = Coefficient of variation.


E rate dropped since the beginning of spring (April 9th), then it kept on being stable until the middle of spring and then it increased starting on May 14th until the end of the maximum deficit of soil humidity (Table 1, Figure 1).

In the phenological observations of the nance selections in study, between the 14th and 28th of May, the spring floral flush (FP) occurred and the beginning of spring harvest (ICP) (Figure 1), and on the last stage of production of the fruit of winter flowering flush. The four nance selections followed the same pattern of transpiration (Figure 1) when the environmental average recorded during May was 24.4 °C, 0 pluvial precipitation, relative humidity at 51 %, average percentage of soil humidity (30 to 60 cm) at 12.18 % and evaporation of 8.76 mm (Table 2).

E rate during the beginning of summer. The four nance selections showed the same transpiration pattern, when the average temperature of June was at 25.2 °C, 0 mm of pluvial precipitation, percentage of soil humidity (30 to 60 cm) (Figure 1) at 10.02 % and 5.44 mm of evaporation. In this season, noticeable differences among the nance selections were present on the transpiration rate (Table 5). A global transpiration rate was observed among the nance selections of 3.64 mmol H2O m-2 s-1. The Amarillo dulce one showed the highest E on this measure date (June 24th) (Figure 1) with 3.9 mmol H2O m-2 s-1. The selections of Amarillo Acido, Ácido Chico and Mejorado behaved statistically the same, whose averages fluctuated from 3.55 to 3.57 mmol H2O m-2 s-1. The selections Amarillo Acido one showed the lowest transpiration rate.

Table 5.

Photosynthetic active radiation (PAR), leaf relative humidity (LRH), leaf temperature (LT), stomatal conductance (gs), transpiration rate (E), and resistance to vapor diffusion (r) of Nance selections in the beginning of summer measurement (june 24th 2013).


Selection PAR
(µmol m-2 s-1)
LRH
(%)
LT
(ºC)
gs
(cm-1 s-1)
E
(µmol H2O cm-2 s-1)
r
(s-1 cm-1)
Amarillo Dulce 1785.0a 74.15a 30.33b 0.01413b 3.8764a 70.888a
Amarillo Ácido 1781.3a 67.08b 29.55b 0.01549a 3.5476b 64.688b
Ácido Chico 1578.6b 66.61b 29.69b 0.01549a 3.5500b 64.625b
Mejorado 1521.8b 66.83b 31.44a 0.01537a 3.5736b 65.125b
Media 1666.7 68.66 30.25 0.0151 3.6368 66.33
Pr>F 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001
CV (%) 12.46 4.64 3.02 4.25 4.32 4.27

TFN10Means with the same letter in columns are not statistically different (Tukey, 0.05). CV = Coefficient of variation.


On the 24th, the highest transpiration rate during dry season was observed, where the severest deficit of soil humidity was detected to a depth of 30 to 60 cm (10.77 %). Phenologically, the nance selections were at stage II of fruit development (10 to 12 mm of ecuatorial diameter), coming from the flush of flowering in spring. The growth process of the inflorescence had finished in the first week of June, and in the first week of September, the beginning of fruit maturity was registered and full harvest occurred at the end of this month. It is emphasized that this is the most abundant crop out of the one that occurred during the year.

Correlation among evaluated variables on nance selections. In general terms, the transpiration rate (E) correlated positively (p ≤ 0.01) with resistance to diffusion (r), with relative humidity closed to the leaf (LRH), with stomatic conductance (gs), and to a lesser degree with the active photosynthetic radiation (PAR); and in a negative form with the temperature of the leaf. Stomatic conductance correlated negatively (p ≤ 0.01) with r, LRH and PAR. Resistance to diffusion correlated positively (p ≤ 0.01) with LRH and negatively with LT. It was observed that a proportional decrease of the LRH as LT increased.

Transpiration rate vs. relative humidity of the leaf (E vs. LRH). Transpiration rate of nance increased along with the increase of relative humidity of the leaf (r = 0.93). Lira-Saldivar (1994) indicates that transpiration is still produced in saturated air, because foliar temperature in the presence of light is usually greater than temperature in encircling air, therefore, the interior of the leaf will normally have a pressure of steam higher than the air surrounding it.

Transpiration rate vs. resistance to diffusion (E vs. r). Because of the restriction to water movement and carbon dioxide stomas present is due to stomatic resistance, a high negative correlation between r and E (r = - 0.93) was observed. Also, because the outward flows of steam are proportional to the conductances (gs), but inversely proportional to resistances (Coombs et al., 1998), a negative correlation was obtained between gs and r (r = - 0.93). The stomatic resistance from the plants increases when soil loses water. In conditions of hydric deficit the cellular membranes become more impermeable, stomatic conductance decreases and a space between the root and the ground is produced, since the radical diameters decrease when the plant loses turgidity, hence forming an extra resistance (Lira-Saldivar, 1994). Even though the availability of water during the interphase ground-to-root can influence transpiration directly, it is more probable that a decline in hydric potential of soil causes a decline in the hydric potential of the leaf and that stomatic resistance is produced (Hernandez-Gil, 2001).

Goldstein et al., (1989) observed in B. crassifolia an initial decrease of the hydric foliar potential and its further recovery during the last hours in the afternoon; which could be linked to the partial stomatic closures that occur during dry season. Meinzer et al., (2001) observed that B. crassifolia did not show changes in hydric potential base nor in minimum hydric potential during dry season, and that paradoxically the more negative base potential kept up during rainy seasons, when the availability of water in the horizons of soil was greater.

Stomatic conductance vs. relative humidity of the leaf (gs vs. LRH). Relative humidity of the leaf showed a negative correlation with the stomatic conductance (r = - 0.93) because while gs inside the leaf increased, transpiration decreased in the same proportion (- 92.88 %). Agbicodo et. al., (2009) pointed out that the mechanism of tolerance to dry implicated that plants can resist the water deficit in soil and it is explained by the maintenance of turgidity of the leaf through an osmotic adjustment, which involves accumulation of solutes, increase in elasticity and size reduction of cells; also, a size reduction of the protoplasmic resistance.

Resistance to diffusion vs. relative humidity of the leaf (r vs. LRH). In relation to the resistance capacity to diffusion of water steam in the leaf, it showed a high degree of association with relative humidity of leaf (r = 0.99) among nance selections during dry season. The hydric state of the leaf from fruit trees is strongly dependent to the steam demand in the atmosphere. This means that the state of water of the leaf varies diurnally a lot more than in the annual crops, and the stress caused by water in the leaf can occur under high demand of steam, even when water in soil is adequate. In fruit trees the strong dependence of water potential of the leaf over transpiration means that the water potential can be regulated by the very response of the stomas to humidity (Schulze et al., 1974).

Stomatic conductance vs. resistance to diffusion (gs vs. r.). Because resistance is reciprocal to conductance, a high negative correlation between both variables presented (r = - 0.93). Even though the stomatic resistance has its base in a physical determinism, this represents the most important regulator of the transpiration, since it is located on the spot where the gradient in the potential of total of water is bigger; this is, between the air surrounding the plant and the guard cell (Azcon-Bieto and Talon,1993; Health et al., 2005). For these reasons, a high negative correlation between r and gs was found, because resistance to the flow of water steam through the stomas is frequently expressed as its reciprocal value and it is called stomatic conductance (Coombs et al., 1998; Azcon-Bieto and Talon, 1993). It has been reported that the specific conductivity of the leaf (hydraulic conductivity by área of the surface of leaf) is higher in evergreen plants; where in B. crassifolia was 1.47 µl·h-1·cm2, supporting the hypothesis that resistance to the water flow in the liquid phase is lower than in evergreen species than in the deciduous (Goldstein et al., 1989).

Stomatic conductance vs. transpiration rate (gs vs. E). Because the flow of water steam depends a great deal on the stomatic conductance (Heath et al., 2005), a high positive correlation between gs vs. E (r = 0.9937). High values of stomatic conductance implicate high values of potential transpiration. B. crassifolia seems to present certain stomatic sensitivity in the presence of relative humidity of the environment, which allows it to partially control water losses during periods of high demand of steam (Goldstein et al., 1989).

Stomatic conductance vs. temperature of the leaf (gs vs. LT). The temperature of the lead (LT) showed positive correlation with stomatic conductance (gs) (r = 0.54), because when increasing LT the gs increased significantly. Nonetheless, the LT showed positive correlation with E (r = 0.54) which meant that when increasing LT the E increased on the leaf. It has been found that LT is a system of analysis of the response of plants to hydric stress in plants; however, extreme differences among nance selections were not present, which could be due to the foliar temperature, which is affected with greater hydric stress. It is known that the stomatic closure at noon, seems to be controlled by external environment, mainly relative humidity in the air and, to a certain degree, by the temperature of the leaf (Azcon-Bieto and Talon, 1993).

In this work, the humidity content in soil as an indicator of availability of water for the roots of the nance selections studied was determined (Table 2). In tropical fruit trees, it has been determined that the abundance of roots and water deficiency in soil is found in the first 30 cm of the surface of the ground (Zekri et al., 1999).

An effect on the variations of the contents of soil humidity over transpiration has been observed; in the same proportion as the first one decreases and approacheso the permanent wilt point, the transpiration rate decreases for an increase in stomatic resistance (Hernández-Gil, 2001). Goldstein et al., (1989) indicated that the fluctuations of soil humidity are muffled at greater depth, and suggests that the quantity of available water is adequate during dry season for woody species that have radical deep systems like B. crassifolia, which maintains the hydric potential constant during the year, plus hydraulic resistances. B. crassifolia has been classified as a species having intermediate strategies of resistance to droughts (Goldstein et al., 1989). The results of this work presuppose that the stress suffered by nance during dry season, could be considered as non-harming, due to the majority of the plantations in Nayarit, which are handle with no watering, without negative effects on the fruit production.

The low rates of transpiration among nance selections found in this research were linked to low contents of relative humidity of the leaf. Nevertheless, soil humidity was going downwards in the measurements on the 28th of May, 11th and 24th of June, the transpiration rate increased. In contrast, it shows an extra measurement of transpiration in rainy seasons, where relative humidity of the leaf was increased a 73.95 % (data not shown) and consequently, transpiration reached values of 3.91 mmol H2O m-2 s-1 (Table 2).

Nance is a dense-foliage tree, which is why the larger the foliar surface is, the higher the water usage will be. Also, it has a sclera-like leaf, a dense cover of trichomas in young leaf, low arithmetic mean in stomatic density (207.36 stomas per mm2), characteristics that possibly allowed it to tolerate hydric stress and escape to drought. The phenological phases of the four nance selections studied, were present in time and with similar intensity to the ones previously reported by Medina-Torees et al., (2012).

Conclusions

The nance selections studied showed a similar pattern of distribution of the transpiration rate (E) during the period of measurements, corresponding to a sinusoidal curve. Said selections showed a decline in E para parallel to the humidity deficit of soil until mid-spring (1.15 mmol H2O m-2 s-1); however, E increased gradually even at a severe low hydric stress, which occurred at the end of spring; it kept on increasing till reaching a maximum value in summer during rainy season when soil was saturated with humidity (3.64 mmol H2O m-2 s-1), it finally decreased at the end of winter to 2.44 mmol H2O m-2 s-1. The variables PAR, LRH, LT, gs, E and r, depended on the period of samplings and the nance selections. The phenological phase of this fruit tree were present in the times and with the same intensity than the ones previously reported, and they were not affected or interrupted by the hydric stress, classifying B. crassifolia as tolerant to hydric stress.


fn1Cite this paper: Medina-Torres, R., Salazar-García, S., Ibarra-Estrada, M.E. (2018). Seasonal variation of transpiration of Nance (Byrsonima crassifolia (L.) H. B. K.) selections under subtropical conditions climate: basic study. Revista Bio Ciencias 5, e320. http://doi.org/10.15741/revbio.05.e320

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Revista Bio Ciencias, Año 12, vol. 8,  Enero 2021. Sistema de Publicación Continua editada por la Universidad Autónoma de Nayarit. Ciudad de la Cultura “Amado Nervo”,  Col. Centro,  C.P.: 63000, Tepic, Nayarit, México. Teléfono: (01) 311 211 8800, ext. 8922. E-mail: revistabiociencias@gmail.com, revistabiociencias@yahoo.com.mx, http://revistabiociencias.uan.mx. Editor responsable: Dr. Manuel Iván Girón Pérez. No. de Reserva de derechos al uso exclusivo 04-2010-101509412600-203, ISSN 2007-3380, ambos otorgados por el Instituto Nacional de Derechos de Autor. Responsable de la última actualización de este número Dr. Manuel Iván Girón Pérez. Secretaria de Investigación y Posgrado, edificio Centro Multidisciplinario de Investigación Científica (CEMIC) 03 de la Universidad Autónoma de Nayarit. La opinión expresada en los artículos firmados es responsabilidad del autor. Se autoriza la reproducción total o parcial de los contenidos e imágenes, siempre y cuando se cite la fuente y no sea con fines de lucro.

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Revista Bio Ciencias por Universidad Autónoma de Nayarit se encuentra bajo una licencia de Creative Commons Reconocimiento-NoComercial-SinObraDerivada 4.0 Internacional

Fecha de última actualización 03 de Noviembre de 2021

 

licencia de Creative Commons Reconocimiento-NoComercial-SinObraDerivada 4.0 Internacional