Research Article Open Access
Monajjem et al., J Plant Pathol Microb 2014, 5:4
DOI: 10.4172/2157-7471.1000239
Volume 5 • Isue 4 • 1000239
J Plant Pathol Microb
ISSN: 2157-7471 JPPM, an open access journal
Keywords: Seed-borne fungi; Rice; Seed quality; Climatic conditions
Introduction
Seed is the primary basis of crop production and is the most
important available input factor for smallholder farmers [1]. In most
parts of the world, smallholder farmers use their produced seed for
next year planting, consequently, they attempt to stock their own
produced seed for several months to several years. Tese seeds are ofen
of poor quality, impure and contaminated with pathogens [2]. Seed
contamination of pathogens during storage could reduce seed vigor,
germination, and cause negative efect on appearance and chemical
composition of seeds in addition to accelerate seed deterioration,
it can also inhibit germination, transmission of the pathogen from
seed to seedling or main plant leading to reduction in crop yield and
threatened food security [3].
Food security of the world depends on sufcient production of
small seed cereals as the cheapest source that provided about 70 of
absorbable energy [4]. Based on seed production, rice is the second
small seed cereals, with area under cultivation about 154 million
hectares, with a global production of 720 million tons of paddy [5].
Rice is very important in Iran and it provides substantial part of the
diet, especially in the three Northern provinces; Guilan, Mazandaranand
and Golestan. Total rice cultivation area in the country is approximately
600 thousand hectares. Guilan province with 230 thousand hectares of
rice felds with an average of 0.8 hectares of land owned by each farmer
has the second place in rice production. In this province, from total rice
seeds which are used by farmers only about 5 percent are considered as
certifed seed and the other 95 percent is produced by farmers and keep
maintained in On-farm storages until sowing [6].
Diferent research studies have stated that in poor storage
conditions, pathogens are the most important factors which not only
cause the seed aging and deterioration during storage, but also seed and
seedling rotting or abnormal production of seedlings in nursery [7,8].
Several reports indicated that the majority of these pathogens that
lead to the production of abnormal seedlings are seed-borne fungi [9].
Te rate of damage of these fungi depends on their genus and species,
rate of density, fungi invaded, environmental conditions, cultivar
susceptibility and interaction of these factors on cultural practice [10].
More than 100 species of fungi have been identifed on rice seeds so
far. However, their severity depends on the time of sampling, location
and varieties are diferent [11-13]. Trough an assessment of rice seed
contamination to diferent seed-born fungi, 8 genera including 12
species of fungi were identifed which among them Bipolaris oryzae with
59% and Alternaria padwickii with 53% had the highest severity [13].
Ahmed et al. [9] in their study on rice seed contamination identifed
9 species of seed-born fungi including; Fusarium oxysporum, F.
moniliforme, Bipolaris oryzae, Alternaria padwickii, Curvularia lunata,
Aspergillus favus, A. niger, Penicillium sp. and Nigrospora oryzae. Tey
*Corresponding author: Salar Monajjem, Phd student in seed technology
Agronomy Group, Gorgan University of Agriculture Science & Nature Resource,
Iran, Tel: +989364146800; E-mail: gromonajem@gmail.com
Received: July 21, 2014; Accepted November 11, 2014; Published November
13, 2014
Citation: Monajjem S, Zainali E, Ghaderi-Far F, Soltani E, Chaleshtari MH, et al.
(2014) Evaluation Seed-born Fungi of Rice [Oryza sativa L.] and that Effect on
Seed Quality. J Plant Pathol Microb 5: 239. doi:10.4172/2157-7471.1000239
Copyright: © 2014 Monajjem S, et al. This is an open-access article distributed
under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the
original author and source are credited.
Abstract
Poor seedling establishment in rice is one of the problems in Guilan province as the second most important
rice-growing locations in Iran. The aim of this study was to evaluate the contamination occurrence of rice seed in
fve locations of Guilan province to seed-borne fungi and their effects on germination characteristics. Five seed
sample of Hashemi variety obtained from leading farmers from each location, and their germination characteristics
and the rate of contamination to Fusarium moniliforme, Bipolaris oryzae, Aspergillus niger, A. favus, Penicillium sp.,
Alternaria padwickii was evaluated using the PDA and standard blotter methods. The assessment results showed
that among the seed-borne fungi, two species A. niger and A. favus exhibited the highest severity in both methods.
Samples from Rasht and Zeybaknar locations showed the most contamination to A. favus and A. niger. A positive
and signifcant linear relationship was observed between daily precipitation and relative humidity with severity of A.
favus and A. niger fungus. A. niger, A. padwickii, daily precipitation and average minimum temperature had the most
infuence on germination characteristics. Among the studied factors, A. niger had high negative impact compared
to other factors on all rice seed germination characteristics. Among the study locations, quality of seeds in Rostam-
Abad in terms of germination percentage, germination rate, germination uniformity and electrical conductivity had
the best state. The results of this study showed that the low precipitation and low daily average humidity along with
higher number of sunshine hours in the Rostam-Abad caused reduction in activity and abundance of fungi, led to
improve the quality of produced seed.
Evaluation Seed-born Fungi of Rice [Oryza sativa L.] and that Effect on
Seed Quality
Salar Monajjem
1
*, Ebrahim Zainali
2
, Farshid Ghaderi-Far
2
, Elias Soltani
3
, Maryam Hosseini Chaleshtari
4
and Maryam Khoshkdaman
5
1
Ph.D Student of Seed Science and Technology
2
Assistant Prof., Dept. of Agronomy, Gorgan University of Agricultural Sciences and Natural Resources
3
Assistant Prof., Dept. of Agronomy, University of Tehran
4
Assistant Prof., Rice Research Institute of Iran
5
Scholar of Rice Research Institute of Iran
Journal of
Plant Pathology & Microbiology
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ISSN: 2157-7471