Volume 20(4), 1- 4, 2016 JOURNAL of Horticulture, Forestry and Biotechnology

www.journal-hfb.usab-tm.ro

1

First results on phytosanitary status of Chinese jujube in Romania Mardare Elena Ştefania1*, Ciceoi Roxana1, Jerca I.O.1, Stănică F.2

1Laboratory of Diagnosis and Plant Protection.Research Center for Studies of Food Quality and Agricultural

Products.University of Agronomic Sciences and Veterinary Medicine of Bucharest, Bdul.Mărăşti, nr. 59, 011464, Bucureşti;

2University of Agronomic Sciences and Veterinary Medicine of Bucharest, Bdul.Mărăşti,

nr. 59, 011464, Bucureşti Corresponding author email: elenamardare184@yahoo.com Abstract Chinese jujube (Ziziphus jujube Mill.), was introduced to Europe during Octavian Augustus, Roman emperor. Two biotypes of Chinese jujube are found in Dobrogea Region at Ostrov, on Danube shore and at Jurilovca, close to the Black Sea. At the Faculty of Horticulture, within the University of Agronomic Sciences and Veterinary Medicine of Bucharest, 11 genotypes of Ziziphus jujuba were introduced from Shanxi Province, China, after 1996. Trees were planted, in the experimental field at 4.0 x 2.5 m and lead as slender spindle. Since then, each genotype was studied regarding the phenology, tree growth and fruit production. The results proved that, in the southern part of Romania, there are suitable natural conditions for jujube growing. Until now, Chinese jujube showed to be resistant to pests and diseases, being cultivated without phytosanitary treatments for 19 years. Our field observations during 2016, demonstrated the existence of four fungus species on the fruits, before the full ripening, fungus that belongs to the Alternaria spp., Rhizopus spp., Fusarium spp. and Monilinia spp. The micromycetes identification was performed by successive isolation and subculturing, using PDA (Potato Dextrose Agar) medium and incubation at 22

0C. The results showed an indirect correlation between the fungus

incidence and the jujube fruit resistance to cracking.

Key words Ziziphus jujuba, genotypes, pathogens, PDA (Potato Dextrose Agar) medium

The Chinese jujube (Ziziphus jujuba Mill.) is

recognized as the most important fruit species

belonging to the Rhamnaceae family. Jujube originates

from China, with a history of over 4.000 years and

recently was widely distributed in Europe, USA, South

and East Asia and Australia. The fruits are consumed

as traditional and functional food, having numerous

beneficial effects on human health, as they contain 23

types of amino acids that are not found in most other

fruits (2). Jujube is rich in amino acids, as tryptophan,

which is very important for the optimal function of the

brain, maintaining a balanced mental state and

preventing ageing process (20). Ziziphus jujuba is

generally known as a source of bioactive compounds,

remarkable both for pharmaceuticals and nutritional

values. The dried jujube fruits are used as food, food

additives and flavours for thousands of years due to

them nutritive values (6). China is the only country

known as jujube exporter; the cultivated area has

reached over 1.5 million hectares (16). The annual

production of fresh jujube fruit reached 400,000 tons

while China exports about 4,700 tons of dried jujube,

of a value of $ 5 million annually (19).

If compared with other fruit species, Ziziphus

jujuba is tolerant to diseases and pests, so its fruits are

less treated with pesticides during the growing season

(11). The ripened fruits are sensitive to infections with

different pathogens, making the post-harvest difficult if

not complied with optimal storage conditions (2,17).

During the storage period, the jujube fruits are

sensitive to diseases caused by various pathogens as

Alternaria alternata (Fr.) Keissl, the most important

pathogen causing infections leading to major losses of

stored production. Also, fruit can be infected by

Monilinia fructicola (G. Wint.) Honey, Penicillium

expansum (Link) and Rhizopus stolonifer (Ehrenb.Fr.)

Vuill. through wounds that occur during the harvest or

packing process (7, 9, 10, 12, 13, 14).

The Chinese jujube fruit cracking is a physiological

disorder during ripening, related to water excess, which

can destroy the crops entirely. The percentage of fruit

yield affected by cracking depends on the water

management during the growing season, the rain falls

and the resistance of each variety to cracking. Guo &

Shan (2010), mentioned cracked fruits attacked by rot

in Laoling County, Shandong Province, in some years,

causing 40% production loss (3). The drip irrigation is

2

the most efficient method of water supply for a

balanced jujube fruit growth and development (15).

Material and Method

The aim of the study was to identify and quantify

the pathogens present on Chinese jujube fruits

immediately after harvest. Samples from 11 Ziziphus

jujuba genotypes grown in the south-eastern Romania,

in the climatic conditions of the year 2016 were

analysed at harvest.

The biological material was represented by 11

genotypes Ziziphus jujuba, namely: Hu Ping Zao,

R1P5, R1P6, R2P5, R2P6, R2P7, R2P8, Hong, R3P2,

R3P3, R3P6, R1P10, introduced in Romania starting

with 1996 (8).

The incidence of existing pathogens was proved by

collecting the mycelium installed on fruits epidermis

and inoculated in Petri dishes with a diameter of 90

mm, on PDA culture medium (potato dextrose agar).

The culture medium (PDA) was prepared according to

the classical recipe (1, 5). After preparation, the

medium was sterilized by autoclaving at 121°C for 20

min.

100 fruits were examined from each studied

genotype. The plates were incubated at 22°C for 10

days. To identify the fungus, the Euromex stereo

microscope and the Euromex Ox Range microscope

were used, following the identification criteria

according to the literature (5).

Results and Discussions

The pathogen species identified on the fruits of

Ziziphus jujube in 2016 belong to Alternaria genus,

Monilinia spp., Fusarium spp. and Rhizopus spp.

Table 1

The incidence of detected micoflora on Ziziphus jujube fruits

Genotypes Alternaria spp (%) Rhizopus spp (%) Monilinia spp (%) Fusarium spp (%)

Hu Ping Zao 6,75 61,5 27,25 4,5

R1P5 5 55 30 10

R2P5 30 50,5 22,5 14,5

R2P6 4 56 30 10

R2P7 2 75 12 11

R2P8 10 20 0 70

Hong 23 35 32 10

R3P2 19 47 27 7

R3P3 20 55 25 0

R3P6 2 25 68 5

R1P10 12 60 28 0

The data presented in the table 1, shows the

development of the four pathogens on PDA medium

collected from the fruit epidermis of the 11 studied

genotypes. The observations made on the incidence of

the microflora detected on Ziziphus jujuba fruits in

2016 indicates that the Rhizopus spp. fungus was

present on all the fruits of the studied genotypes.

Rhizopus had the highest incidence values on R2P7

genotype (75%), followed by genotypes: Hu Ping

Zao(61, 5) and R1P10 (60%). The R3P6 genotype had

the lowest incidence value for Rhizopus spp. (25%).

The highest incidence value obtained was 75% for

Rhizopus spp. on R2P7, 70% for Fusarium spp. on

R2P8, 30 % for Alternaria spp. (R2P5 genotype) and

for Monilinia spp. 68% (R3P6 genotype).

The Monilinia spp. fungus was present with the

highest incidence rates on genotypes R3P6 (68%), and

R1P10 (28%), while the lowest incidence was observed

on R2P7 genotype (12%).

For Alternaria spp., highest incidence values were

noticed at R2P5 genotype (30%) and the lowest values

were found to R2P7 and R3P6 genotypes (2%).

The Fusarium spp. fungus was not detected on

R3P3 and R1P10. The highest incidence values were

found instead, for R2P8 (70%) and the lowest values

were found at R3P2 genotype (7%) and R3P6

genotypes (5%).

3

Fig.1 The fungus development on the Chinese jujube fruit on PDA medium, after 10 days from inoculation

a - Fusarium spp.; b - Alternaria spp.; c - Monilinia spp. (original)

Fig. 2 Attack of Rhizopus spp. on Chinese jujube fruiton Hu Ping Zao genotype (a, b) and R2P7 genotype (c) (original)

Fig. 3 Attack of Monilinia spp. on the Chinese jujube fruit R2P8 (a) and Hu Ping Zao (b) (original)

Conclusion

Through the analysis on fruits samples from the

Chinese jujube plantation in Bucharest, were identified

the following pathogens: Alternaria spp.,

Rhizopusspp., Fusarium spp. and Monilinia spp. The

highest incidence of pathogens presence was

determined for Rhizopus spp. on genotype R2P7,

followed by genotype Hu Ping Zao. Monilinia spp. was

present on Hu Ping Zao, with the highest value at R3P6

genotype.

The fungus Fusarium spp. has been identified with

the highest incidence on R2P8 genotype. Hu Ping Zao

genotype had incidence values below 4,5%.

4

Bibliography

1.Constantinescu O., - 1974- Metode şi tehnici în

micologie (Methods and techniques in mycology). Ed.

Ceres, Bucureşti

2.Gao, Q. H., Wu, C. S., & Wang, M .- 2013 - The

jujube (Ziziphus jujuba Mill.) fruit: a review of current

knowledge of fruit composition and health

benefits. Journal of agricultural and food

chemistry, 61(14), 3351-3363

3.Guo, Y. X., & Shan, G. H.-2010 - The Chinese

jujube. Shanghai Scientific and Technical Publishers,

Shanghai, China.

4.Hulea A.,-1969- Ghid pentru laboratoarele de

micologie şi bacteriologie (Laboratory guide for

mycology and bacteriology). Ed. Agrosilvică,

Bucuresti

5.Hulea A., Iliescu P., 1986.

Determinatorpentruidentificareamucegaiurilor potential

toxigene (A guide for toxigenic molds

determination).Societatea de MedicinăVeterinară din

R.S.România, Bucureşti.

6.Li, J. W., Fan, L. P., Ding, S. D., & Ding, X. L.-

2007- Nutritional composition of five cultivars of

Chinese jujube, Journal of Agricultural and Food

Chemistry, 103(2), 454-460.

7.Li, M., Yu, M.L., Zhang, Z.Q., Liu, Z.G., Pan, Y.,-

2012.-Control of black spot disease caused by

Alternaria alternata on jujube (Ziziphus jujuba Mill.

cv. Dongzao) using Harpin Xooprotein. The Journal of

Horticultural Science and Biotechnology 87, 250–254.

8.Stănică F.- 2016 - 20 Years of Jujube Research in

Romania. Jujube Workshop 2016 - Chinese Jujube – a

new fruit for Europe. USAMV Bucureşti – 9-12

October 2016.

9.Tian, S. P. - 2000 - Manual of storage and

manufacture of postharvest fruits and

vegetables. Jujube. China Agriculture Press, Beijing,

China, 120-123.

10.Tian, S., Qin, G., Xu, Y.,-2005- Synergistic effects

of combining biocontrol agents with silicon against

postharvest diseases of jujube fruit. Journal of Food

Protection. 68, 544–550.

11.Velkoska-Markovska, L., & Petanovska - Ilievska,

B.- 2013- Optimization and development of SPE-

HPLC-DAD method for the determination of atrazine,

malathion, fenitrothion and parathion pesticide residues

in apple juice. Macedonian Journal of Chemistry and

Chemical Engineering, 32(2), 299-308. 12.Wang, L., Wu, H., Qin, G., & Meng, X. -2014-

Chitosan disrupts Penicillium expansum and controls

postharvest blue mold of jujube fruit. Food Control, 41,

56-62..

13.Yan, J., Cao, J., Jiang, W., Zhao, Y.,-2012- Effects

of preharvest oligochitosan sprays on postharvest

fungal diseases, storage quality, and defense responses

in jujube (Zizyphus jujuba Mill. cv. Dongzao) fruit.

Horticultural Science (HORTSCI. 142, 196–204.

14.Yan, J., Li, J., Zhao, H., Chen, N., Cao, J., Jiang,

W.,-2011- Effects of oligochitosan on postharvest

Alternaria rot, storage quality, and defense responses

in Chinese jujube (Zizyphusjujuba Mill. cv. Dongzao)

fruit. Journal of Food Protection. 74, 783–788.

15.Yaragattikar, A. T., & Itnal, C. J. -2010- Studies on

Water Requirement During Early Growth Stages of

Ber Through Drip Irrigation. Karnataka Journal of

Agricultural Sciences, 16(1).

16.Yi, X. K., Wu, W. F., Zhang, Y. Q., Li, J. X., &Luo,

H. P. -2012- Thin-layer drying characteristics and

modeling of Chinese jujubes. Mathematical Problems

in Engineering, 1-19.FAO. Jujube;

17.Zhang, Y. X., & Liu, D. H. -2008- The processing

status and developmental foreground of Chinese date

in our country. Storage & Process, 5, 15-17.

18.Zozio, S., Servent, A., Hubert, O., Hiol, A., Pallet,

D., Mbéguié-A-Mbéguié, D.,- 2014- Physicochemical

and biochemical characterization of ripening in jujube

(Ziziphus mauritiana Lamk) fruits from two accessions

grown in Guadeloupe. Horticultural Science

(HORTSCI)175, 290–297

19.*** http://www.fao.org 1993

20.***www.surplusdesanatate.