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Analele ştiinţifice ale Universităţii „Al. I. Cuza” IaşiTomul LVII, fasc. 2, s. II a. Biologie vegetală, 2011

PHYSIOLOGICAL AND BIOCHEMICAL ASPECTS AT APPLE VARIETIESCULTIVATED IN THE NE REGION OF ROMANIA

DOINA ATOFANI*, ANCA ANDRO*, IRINA BOZ*, CLAUDIA PĂDURARIU*,LILIANE MEGUEKAM TEKAM**, B. MANEA***, CARMEN LAMBAN****,

MARIA-MAGDALENA ZAMFIRACHE*

Abstract: The article discusses about the variation of a few biochemical and physiological indicatorswhich were performed on the foliar surface (the pigments chlorophyll content, the water content, the dry mattercontent, the intensity of photosynthesis and respiration process) and about the qualitative indicators of fruits (thetotal acidity and the concentration of sugar) at three apple varieties: Golden delicious, Idared and Starkrimson,cultivated in the orchard “Mărul de aur”, Vaslui county. The investigations were determined in the phase of fruitripening maturation, 2011. There were used leaves from two cardinal points taking into account the exposition ofthe trees: east and west. The results indicate functional and biochemical differences depending on each applevariety, geographical exposition of the tree and air humidity during the investigations.

Keywords: apple variety, biochemical and physiological indicators, environment conditions,maturation fruit phase.

Introduction

Apple tree is one of the most cultivated tree fruits. Apple takes part from Rosaceaefamily, Pomoideae subfamily, Malus genus, which contains approximately 40 species.During time, there were obtained many apple varieties, around 10000 varieties. There was amajor interest for this tree, because of its fruits and its properties [8].

In our country the most well known and consumed apple varieties are: Goldendelicious, Idared and Starkrimson.

Starkrimson variety was obtained in U.S.A. (1958), from a variation of the budfrom Starking delicious. Picking time is the middle of October. Fruit size is medium. Theconsumption of fruits is from November till March. The fruit has dense flesh, is very sweetand quite juicy [7]. Idared was obtained in U.S.A. (1942). The fruits are consumed fromNovember until May. They are not harmed during transport and keeping. This variety isvery productive. Golden delicious was obtained from seeds, in the U.S.A. (1916). The fruitsare consumed from October till April. The fruits are medium to large, yellow, sweet, juicy,strong flavor, good storage.

There were conducted investigations (physiological and biochemical parameters)on the leaves from these apple varieties.

* Alexandru Ioan Cuza University, Faculty of Biology, Bd. Carol I, no. 11, Iasi – 700506, Romania,ro_doina@yahoo.com** Yaoundé I University – Cameroun*** S. C. “Mărul de aur” S.R.L., Vaslui, Romania**** S. C. P. Miroslava, Iaşi, Romania

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Materials and methods

The investigations were conducted in the “Mărul de aur” orchard, Vaslui duringAugust and September, 2011, on the leaves from the branches with different orientation atthe Sun. For the physiological processes it was used Lci Portable Photosynthesis System(ADC BioScientific Ltd, Hoddesdon, UK). The physiological processes investigated were:photosynthesis process and respiration process. This analyzer performs recording andmeasurements also other parameters, very important in photosynthesis process: thephotosynthetically active radiation incident on leaves surface, leaf temperature, stomatalconductance etc.

The atmosphere conditions (temperature and air humidity) were registered withTESTO 625. The total water contents and dry matter were determined with the gravimetricmethod. The pigments content was determined with the spectrophotometric method Mayer-Bertenrath [1].

The percentage concentration of sucrose in fruits was determined by therefractometric method using the refractometer KRUSS OPTRONIC. For total acidity of thefruits it was used the titrimetric method with NaOH. The experiments were carried out inthe Plants Physiology Laboratory of the Faculty of Bioloy from Iassy.

Results and discussions

Physiological investigations were performed on leaves from the branches withdifferent orientation from the Sun on August and September, 2011. The physiologicalinvestigations were correlated with the atmosphere conditions: air temperature, air humidityand the photosynthetically active radiation incident on leaves surface.

During the experiments on the field, in August, the values for air temperaturevaried between 18.1 and 22.7°C for the east part, and between 18.1 – 23.1°C for the westpart of the trees (Tab. I). For August the values for air humidity registered 51.6 – 70.6% forthe east part and 52.2 – 71% for the west part of the trees (Tab. I). For September, the airtemperature varied between 27.2 and 30.4°C for the east part and between 23.2 and 28.6°Cfor the west part of trees (Tab. II). The air humidity varied between 37.1 and 49.8% (eastpart) and between 36.1 and 51.8% (west part).

Table I. Atmosphere conditions values for August, 2011, during the experiments on the field; T1-airtemperature before the investigations; U1- air humidity before the investigations; T2-air temperature

after the investigations; U2- air humidity after the investigations

Starkrimson Idared Golden delicious

eastside

westside

eastside

westside

eastside

westside

T1 (°C) 18.1 18.1 21.4 19.5 22.4 23.1H1 (%) 70.6 71 59.4 67.6 52.7 52.2T2 (°C) 18.8 18.3 21.5 19.9 22.7 22.4H2 (%) 69 71 58.4 65.3 51.6 55.5

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Table II. Atmosphere conditions values for September, 2011, during the experiments on the field; T1-air temperature before the investigations; U1- air humidity before the investigations; T2-air

temperature after the investigations; U2- air humidity after the investigations

The photosynthetically active radiation incident on leaves surface registered highervalues during August (Tab. III) than September (Tab. IV) for the east side of the apple tree.The values are changed for the west side during September. In this case air temperature washigher for this month.

Table III. The photosynthetically active radiation incident on leaves surface during August

Starkrimson Idared Golden deliciouseast side west side east side west side east side west sideQleaf

(µmol/m2/s) 1179.8 47.8 1436.7 99.3 1391.2 85.4

Table IV. The photosynthetically active radiation incident on leaves surface during September

Starkrimson Idared Golden deliciouseast side west side east side west side east side west sideQleaf

(µmol/m2/s) 575.5 65.7 686.7 134.4 1092.2 208.7

Gucci and Crappadelli (1989) (cited by Burzo, 1999) [2] confirmed that theintensity of photosynthesis process varies depending on the light radiation received at theleaves surface, which depends of the position of the leaves in the tree. In this way,correlating with the light radiation values registered, there can be seen differences of thephotosynthesis intensity on the both sides of the tree branches (Fig. 1, Fig. 2).

The photosynthesis intensity varies also because of the different trees varieties [2].Starkrimson variety has higher values for the photosynthesis intensity than Idared andGolden delicious. This process depends also of the atmosphere conditions. The valuesdecreased in September than in August on the east side of the tree. In September on thewest side the values increased. There were registered high values for the air temperature inSeptember.

As it is presented in the literature [3] during fruit maturation, takes place adecreasing of the chlorophyllian pigments content and an increasing of carotenoid pigmentscontent (Fig. 5, Fig. 6). The chlorophyllian pigments present relative the same values inthese two months (Fig. 3, Fig. 4), the values are between 0.008 and 0.018 mg/g fresh matterfor chlorophyll “a”, and values between 0.003 and 0.006 mg/g fresh matter for chlorophyll“b”. The values obtained for carotenoid pigments varied between 29.08 and 57.88 mg/g

Starkrimson Idared Golden deliciouseastside

westside

eastside

westside

eastside

westside

T1 (0C) 30.0 28.2 29.3 26.0 27.2 23.2H1 (%) 37.4 36.7 38.6 44.0 49.8 51.8T2 (0C) 30.4 28.6 29.4 25.6 28.0 23.6H2 (%) 37.1 36.1 38.5 44.7 45.8 49.1

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fresh matter. During September there was a balance of the content for the pigments on theboth sides of the tree comparative with August.

The intensity of respiration is correlated with the intensity of photosynthesis. As inliterature is mentioned, the respiration intensity decreases from spring to autumn [4]; in ourexperiments we also obtained smaller values in September than in August. In the Figure 7and Figure 8 there are presented the values for the months taken into study. The east sidehas o stronger intensity for all the three apple varieties, except Golden delicious variety forSeptember.

In September the dry content increase slightly than in August for all the threevarieties while the water content keeps being higher than the dry content. The values forwater content and the dry content are balanced for the both months and for all the varietiesstudied. This shows a good hydration of the foliar mesophyll and a normal develop of themetabolic processes in the leaves.

At the end of this study, after harvest time, there were determined biochemicalparameters of the apple fruit. It was determined the total acidity and sugar content of thefruits for the three varieties taking into study: Starkrimson, Idared and Golden delicious.The highest acidity of the fruit has Idared variety with 0.34% malic acid, followed byGolden delicious with 0.21% malic acid. The smallest acidity was obtained for Starkrimson(0.17%). The highest value for Idared apple variety makes it recommended for the diabeticpersons.

In literature it is specified 15% concentration of sucrose for the apple fruits [5].Our results are around this value: 17% concentration of sucrose for Starkrimson, 16.4%concentration of sucrose for Golden delicious and 13.5% concentration of sucrose forIdared.

Conclusions

There is a strong correlation between the intensity of the photosynthesis process,air temperature, air humidity and the intensity of the light radiation received at the leavessurface. The results are compared with the literature [2].

The physiological processes during the vegetation phase taking into study arebalanced, which induce a good maturation of fruits till harvest time.

It’s very important to know the total acidity and the sugar content of fruits,especially for people with medical problems (diabetes). As it is mentioned in the literature,Idared variety has a small sugar content which is indicated for persons with diabetes.Golden delicious is recommended for people with sensibility for acidity.

AcknowledgementThis investigation was supported by Program “Developing the innovation capacity

and improving the impact of research through post-doctoral programmesPOSDRU/89/1.5/S/49944”.

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REFERENCES

1. BOLDOR O., RAIANU O., TRIFU M., 1983 – Fiziologia plantelor, lucrări practice. Edit. Didactică şiPedagogică, Bucureşti.

2. BURZO I., 1999 – Fiziologia plantelor de cultură. Întreprinderea Editorial-Poligrafică Ştiinţa, Chişinău.3. FLEANCU MONICA, 2005 – Research regarding the physiological and biochemical changes in apple fruits

during maturation and senescence processes. Scientifical papers USAMVB, Serie B Horticulture,XLVIII, Bucharest: 385 – 388.

4. FLEANCU MONICA, 2007 – Corelation among some physiological processes in apple fruit during growingand maturation processes. Int. J. Agri. Biol., 9, 4: 613 – 616.

5. GHERGHI A., BURZO I., BIBICU MONICA, MĂTGINEANU LIANA, BĂDULESCU LILIANA, 2001 –Biochimia şi Fiziologia Legumelor şi Fructelor, Edit. Acadamiei Române, Bucureşti.

6. NICOLAE I., 2010 – Research regarding the diurnal dynamics of some physiological processes in Malusdomestica Borkh. Muzeul Olteniei Craiova, Oltenia. Studii şi comunicări. Ştiinţele Naturii, 26, 1: 67 –72.

7. MIHĂESCU G., 2007 – Pomicultura de la A la Z, Edit. ASAB, Bucureşti.8. PÂRVU C., 2004 – Enciclopedia plantelor, III, Edit. Tehnică, Bucureşti.

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D. Atofani, A. Andro, I. Boz, C. Pădurariu, L. M. Tekam, B. Manea, C. Lamban, M.-M. ZamfirachePLATE I

0.00

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photosynthesis photosynthesis photosynthesis

Starkrimson Idared Golden delicious

east side

west side

August

µmol CO2/m2/s

Figure 1. Photosynthesis intensity during August

0.00

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photosyntesis photosynthesis photosynthesis

Starkrimson Idared Golden delicious

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September

µmol CO2/m2/s

Figure 2. Photosynthesis intensity during September

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D. Atofani, A. Andro, I. Boz, C. Pădurariu, L. M. Tekam, B. Manea, C. Lamban, M.-M. ZamfirachePLATE II

0.000

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chl. "a" chl. "b" chl. "a" chl. "b" chl. "a" chl. "b"

Starkrimson Idared Golden delicious

east side

west side

August

Figure 3. Chlorophyllian pigments content during August (mg/g)

0.000

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chl. "a" chl. "b" chl. "a" chl. "b" chl. "a" chl. "b"

Starkrimson Idared Golden delicious

east side

west side

september

Figure 4. Chlorophyllian pigments content during September (mg/g)

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D. Atofani, A. Andro, I. Boz, C. Pădurariu, L. M. Tekam, B. Manea, C. Lamban, M.-M. ZamfirachePLATE III

0.000

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pigm. caroten. pigm. caroten. pigm. caroten.

Starkrimson Idared Golden delicious

versant estic

versant vestic

lunaaugust

Figure 5. Carotenoid pigments content during August (mg/g)

0.000

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pigm. caroten. pigm. caroten. pigm. caroten.

Starkrimson Idared Golden delicious

versant estic

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lunaseptembrie

Figure 6. Carotenoid pigments content during September (mg/g)

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D. Atofani, A. Andro, I. Boz, C. Pădurariu, L. M. Tekam, B. Manea, C. Lamban, M.-M. ZamfirachePLATE IV

0 0.2 0.4 0.6 0.8 1 1.2 1.4

Starkrimson

Idared

Golden delicious

west side

east side

August

µmol/m/s CO2

Figure 7. Respiration intensity for August

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

Starkrimson

Idared

Golden delicious

west side

east side

September

µmol/m/s CO2

Figure 8. Respiration intensity for September