ISSN 10227954, Russian Journal of Genetics, 2010, Vol. 46, No. 7, pp. 836–840. © Pleiades Publishing, Inc., 2010.
Original Russian Text © J. Van etovi , M. Vidakovi , D. Ignjatovi Mici , A. Nikoli , K. Markovi , V. An elkovi , 2010, published in Genetika, 2010, Vol. 46, No. 7, pp. 940–944.
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Absence of pollen and plant inability to produce
functional pollen grains is known as male sterility.
Male sterility can be determined by nuclear (genie
male sterility) or cytoplasmic (cytoplasmic genetic
male sterility –
) genes. CGMS (onwards
referred to as CMS) is successfully used in commercial
production of hybrid seed, avoiding the drawbacks of
hand or mechanical emasculation . Three main
types of CMS were identified in maize: CMST,
CMSS and CMSC. Male sterile cytoplasm is distin
guished by specific nuclear genes (
restore pollen fertility. These genes, restorers of fertil
ity, suppress the malesterile effect of the cytoplasm,
allowing the production of viable pollen.
The concept of restorer cytoplasm was theoreti
cally proposed by Hermsen [2, 3]. Hermsen suggested
that existence of different types of cytoplasmic male
sterility in maize, the respective restorer genes for each
of them and the whole series of nuclear genes (
genes) causing male sterility might mean that a
restorer cytoplasm could exist for some or all
Finding a restorer cytoplasm would allow hybrid seed
production without genetic uniformity, generally
introduced by any type of cytoplasmic male sterility.
Only limited amount of research was done in this area,
including research on cotton , barley  and maize
, Restorer cytoplasm was not found in any of the
above researches. Being aware of restorer cytoplasm’s
concept significance in seed production an experi
The article is published in the original.
ment was set to search through all the Maize Research
Institute (MRI) gene bank accessions for the presence
of the restorer cytoplasm for the gene
. A conclu
sion was reached that a restorer cytoplasm for the gene
does not exist .
While searching for restorer cytoplasm almost a
hundred new sources of cytoplasmic male sterility
were discovered, distinguishable by their overwhelm
ing frequency of male sterile plants in segregating test
progenies. The types of CMS involved were unknown.
Tester lines containing nuclear
genes are tradition
ally used for identification and classification of CMS
types. However, testcrossing procedure is time con
suming, labor intensive and not precise. Development
and appliance of molecular methods revealed that
mutations responsible for CMS are located in mito
chondrial DNA (mtDNA) in many plant species .
It was confirmed that chimeric genes – DNA parts
with open reading frames (ORF) that comprise
sequences derived from different genes, are responsi
ble for cytoplasmic male sterility. Himeric T
gene was detected in mtDNA CMST  chimeric
gene in mtDNA CMSC  and a repeated
DNA region “R” containing two ORFs in mtDNA
CMSS . Thus, classification of CMS types can be
more effectively done using specific molecular mark
ers designed for target mutations.
The objective of the experiment presented in this
paper was to identify the types of cytoplasms of the
newly discovered sources of CMS within genebank
collection in field experiments during the search for
The Structure of Sterile Cytoplasm Types
within a Maize Genebank Collection
J. Van etovi , M. Vidakovi , D. Ignjatovi Mici , A. Nikoli , K. Markovi , and V. An elkovi
Maize Research Institute “Zemun Polje”, Belgrade, 11185 Serbia;
Received July 3, 2009
—Maize Research Institute (MRI) gene bank maintains a collection of 6000 maize accessions.
Within this collection over 100 sources of cytoplasmic male sterility (CMS) were found in field trials, i.e. more
than 2% of the total accession numbers. These sources are distributed among Yugoslav openpollinated vari
eties (4.56% of them contain CMS), as well as introduced heterozygous genotypes and inbred lines. In order
to identify cytoplasm types the genebank sources of CMS were screened using a PCR assay with specific
primers for C, T and S cytoplasms. Predominant cytoplasmic male sterility type among the analyzed acces
sions was CMSS. Results were inconclusive for three accessions, i.e. different results for the progenies of two
ears per accession were obtained. For another two accessions a new PCR product profile was identified, con
sisting of one band characteristic for CMSS and one unspecific for any of the three CMS types. The PCR
approach enabled a simple, fast and reliable large scale screening of maize cytoplasm among MRI gene bank
accessions, significantly reducing time for cytoplasm characterizations compared to classical method of test
ing with restorers for each known type of CMS.
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