A Database for Triticeae and Avena
II. 3. Influence of genotype on mutagenic variability in barley (H.
vulgare L.) following colchicine treatment.
Juliana Balkanjieva, Institute of Genetics, 1113 Sofia, Bulgaria.
The present study was undertaken as an attempt to determine the characteristics
of mutagenic variability in colchicine treated barley depending on the
Various accessions of multi-row winter barley cultivars were used as
experimental material, namely:
Bulgarian cultivars - Sofia 1337 and No. 1241 (Hordeum sativum
Lessen, ssp. vulgare L. gr. inaequale tetrastichum), developed by
individual selection in local barley populations, and Markeli 2 (Hordeum
sativum Lessen, ssp. vulgare L. gr. inaequale tetrastichum),
a comparatively new cultivar obtained by gamma irradiation of the French
Rumanian cultivar - Moara Domniasca (Hordeum sativum Lessen,
ssp. vulgare L. gr. inaequale tetrastichum), developed by individual
selection in a local barley population.
French cultivars - Ajer and Maglon (Hordeum sativum Lessen,
ssp. vulgare L. gr. inaequale tetrastichum), developed as a result
of complicated intercultivar hybridization.
German cultivar - Vogelsänger Gold (Hordeum sativum Lessen,
ssp. vulgare L. gr. inaequale tetrastichum), developed by intercultivar
Seeds of the named cultivars were treated with a 0.125% water solution
of colchicine. A hundred seeds of relatively equal size were selected from
each cultivar and presprouted in water for 7 h. Then they were placed to
germinate in the dark at room temperature (18-20°C). At the time when
the coleoptiles were about 1 cm long the tips were cut and the whole sprouting
seeds with rootlets and coleoptiles were immersed in 0.125% water solution
of colchicine for 2.30 h, rinsed in running water and planted in pots.
The plants were grown in glass houses under controlled conditions.
During the vegetation period observations were carried out on the plants
concerning time and course of the phenological phases and type of changes
appearing as a result of colchicine treatment. The study on C1 mitosis
was performed on 5 to 51 plants of each cultivar. The chromosome number
in at least 30 cells was recorded.
Data obtained by the observations on the morphological and biological
changes which occur in barley plants following colchicine application indicate
clearly the presence of specific cultivar differences related with the
biological characteristics and with accession. Considerable inhibition
of plant growth and development, particularly in the first days post planting
was typical for all plants treated from each cultivar. The changes became
evident as soon as the first leaf appeared. It grew much wider, but shorter.
The stem base gradually thickened and cracked lengthwise. These plants
had wide, long, sometimes very long, succulent leaves with a clearly expressed
venation. The stems were thick. Changes occurred also in spike seediness.
Usually almost all spikes had seeds only in the middle part, while the
lower and upper parts were completely sterile (Gentcheff, 1947; Schumann,
1971). Difference between the grain size of diploid and tetraploid plants
was also observed.
The accession and the biological characteristics of the cultivar had
a definite influence on plant vigor, length of vegetation period, and on
yield structural elements of the individual plants.
Cultivars developed by intercultivar hybridization and mutagenesis were
distinguished by higher variability rate. The inhibiting effect of colchicine
was most pronounced on cv. Markeli 2, and least on cv. Sofia 1337. The
plants of cv. Ajer were characterized by lowest viability (only 5% of them
reached the spike formation phase), while cv. Markeli 2 plants had highest
viability. CV. 1241 was distinguished by longest vegetation period, while
cv. Maglon by the shortest one. Shortening of the vegetation period was
observed in cv. Maglon, while prolongation of the period - in cv. Markeli
The results obtained by cytological investigations on mitosis showed
considerable differences between the individual cultivars concerning the
changes in cell chromosome number. It is evident from data presented in
Table 1 that the percentage of plants with tetraploid chromosome number
of the cell varies from 0 to 29.62. Cv. Maglon is distinguished by its
highest percentage of tetraploid plants. Only in cv. Sofia 1337 no changes
in chromosome number were observed. In most cultivars, despite the occurring
phenotypical changes in their individual characters, the predominating
part of cells recorded had a diploid chromosome number. This is particularly
true for cv. No. 1241 and cv. Sofia 1337 developed by individual selection,
and for cv. Vogelsänger Gold.
Table 1. Chromosome number of root tip somatic cells
in C1 plants
Results obtained by the investigations on mutagenic variability characteristics
in various cultivars following colchicine treatment substantiate the following
l. The multi-row winter barley cultivars studied have a specific reaction
to 0.125% water solution of colchicine which depends on their genotype.
2. Cultivars developed recently by use of complicated intercultivar
hybridization have higher sensitivity and are more inclined to tissue polyploidization,
while those developed by individual selection in local populations do not
have the aptitude of this kind.
3. Phenotypic changes observed in the cultivars as an effect of mutagenic
colchicine treatment are not always accompanied by changes in their chromosome
Gentcheff, G. 1946/47. A new technics of inducing polyploidy in plants
by colchicine treatment. Annuaire de l'universte de Sofia, Faculte d'agronomie
et sylviculture, tome XXV, Livre 1 - Agronomie.
Schumann, G. 1971. Kolchizinapplikationen zum Zeitpunkt der Anthese
zur Erzeugung polyploider Pflanzen, untersucht an Roggen und Sommergerste,
Arch. Züchtungsforsch. Bd 1. H.2. S. 139-146.
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