KARYOTYPE ANALYSIS OF TWO SPECIES OF SALSOLA FROM YAZD, IRAN

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1 KARYOTYPE ANALYSIS OF TWO SPECIES OF SALSOLA FROM YAZD, IRAN Rahavi Mostafa 1, 2, Zarei Gholamreza *3, Yazdanbakhsh Zahra 4 1-Department of Botany, Fars Science and Research Branch, Islamic Azad University, Marvdasht, Iran 2-Department of Botany, Marvdasht Branch, Islamic Azad University, Marvdasht, Iran 3-Department of Agronomy, Maybod Branch, Islamic Azad University, Maybod, Iran 4-Department of Plant Protection, Abarkouh Branch, Islamic Azad University, Abarkouh, Iran Abstract: Solsola has about 100 species all over the world and 48 species in Iran. Identification of different species of this genus is difficult for botanist due to species varieties, no easy identifiable features, changing habitat and morphological differences of young plants and adult ones. In this karyotype analysis, we investigated two species of Salsola named: S. crassa subsp. turcomanica (litw.) Freitag and S.abarghuensis Assadi. The results showed that the chromosome number in S. crassa subsp. turcomanica and S. abarghuensis is 2n=18. The karyotype of two species under the study was rather similar and both had 8 pairs of metacentric and one pair of sub-metacentric chromosome. Keywords: Salsola, karyotype, chromosome number Introduction Salsola is one of the big genus of Chenopodiaceae family which has an important role in improvement and reviving of relatively arid and salty lands. This genus was first named by Line in 1753 and now it has about 100 species among world which 48 types is scattered in Iran. Salsola is the biggest in subfamily of spirolobeae. Because of species varieties, no easy identifiable features, very changing habitats and morphologically differences among young and adult plant, it is difficult for botanists to identify different species of this plant [1]. Based on various values of this genus, its unknown research aspects such as genetic studies toward promoting genetic potential are focused. The first step toward identification of genetic features of a plant, understands the status of its chromosomes. Using chromosome information we can compare the species and their population. Populations belonging to one species reveal their adaptive specific genome with the environment in which they grow. Increasing adaptive differences may create new varieties and even new species in plants' habitat. So chromosomes are appropriate factors by which we can determine plants' evolutionary path. Chromosome differences are different from morphological, physiological and ecological ones. Because these differences show differences in gene function which differ with changing environmental factors. While chromosome differences, are more or less resulted from genetic content of individuals. Size difference in chromosomes can explain differences in gene products or proteins which are produced by an individual or it can show duplication of genes that can affect the amount of synthesis of protein types. Differences in morphology of karyotype shows differences in gene arrangement and this can clearly affect the way gene produces recombination or dispersion in Mendelian heritage. Finally, difference in number of chromosomes can show differences existing in gene arrangement or duplication of genes or both [2,3]. Bakhshi Khaniki and Maroof [4] after studying the karyotype of some species of Salsola, reported that chromosome number in S. turkestanica, S. dendroides and S. incanescens is 2n=18 and in S. tomentosa, S. crassa and S. Kali is 2n=36. The karyotype of studied species was relatively similar. Two species, S. crassa and S. Kali with 15 pairs of metacentric chromosomes and 3 pairs of sub metacentric chromosome

2 have lower karyotype symmetry compared to other species. Xiaowei et al. [5] analyzed the karyotype of four species of Salsola and reported X=9 for the studied species. Zarei et al. [6] reported chromosome number 2n=18 for Salsola abarghuensis and Mirzadeh et al. [7] also reported 2n=18 for Salsola yazdiana. There are other cytologic studies about Salsola genus: Salsola kali 2n=36 [8], Salsola oppositifolia 2n=72 [9] and Salsola kali ssp. austroafricana 2n=18 [10] Due to the importance of chromosomic studies in solving taxonomy, evolution and modification of plants questions, this study was carried out to karyologically study two types of Salsola specie. Method and instruments In order to carry out the research, seeds of studied species were collected from field. Seeds of Salsola abarghuensis were collected from Abarkouh's desert and Salsola crassa subsp. turcomanica seeds were collected from Ardakan (Yazd province, Iran). In order to study mitosis we used apical meristems of young roots. So the given species were cultured separately in petridishes and were placed in room temperature for germination. After germination, the shoots which had 1.5cm length, were selected and placed in pretreatment of 8-hydroxy quinolin 2mM for three hours. After being washed, the samples were maintained in carnoy fixator solution for 24 hours (3:1, ethanol:acetic acid glacial). After then, the samples were extracted and the end of roots were cut. The cutting roots were placed in Hcl 1 M for 7 min in 60 C. Then they were stained with aceto orcein for 3 hours. After staining, the samples were studied with light microscope and digital images were taken from appropriate cells. Then the images were investigated using Micromeasure 3.0 software. For each species, 3 appropriate chromosome samples were studied. Measurements taken from each chromosome consisted of the long arm, short arm and total chromosome length. Based on these measurements, the ratio between the long and short arms (Pa-Values) was calculated for classifying the different types of chromosomes. These categories are M, m, sm, st, t and T for the respective Pa-Values of 1.00, , , , and >37 (Levan et al. 1964). The L% was calculated as the percentage of the length of each chromosome in the diploid genome. After detection of chromosome characteristics, ideogram was prepared. Results and discussion Salsola crassa subsp. turcomanica This species has chromosome number of 2n=18 (figure1). Among the total of 9 pair chromosomes of this species, 8 pairs are metacentric and 1 pair is submetacentric. The longest chromosome has the length of 5.12 µ and is metacentric and the shortest one has the length of 3.78 µ and is metacentric (table1). The length of long arm of chromosomes is between 2.11 and 2.78 µ and the length of short arm of chromosome is between 1.49 and 2.33 µ. The length of total chromosomes of this species equals to µ. This species due to having more metacentric chromosomes and less sub metacentric chromosomes has a symmetric karyotype. According to the classification of Stebbines [11], karyotype group of this specie was determined to be 1A. The karyotype formula of this species is as 4M+12m+ 2sm. The ideogram of chromosomes is illustrated in figure 2.

3 Figure1. Mitotic metaphase chromosomes of Salsola crassa subsp. turcomanica Chromosome No. Table1. Morphometric data on chromosomes of the diploid species Salsola crassa subsp. turcomanica (2n=18) Long Short total Pa-value arm(l) arm(s) chromosome L% (L/S) (µ) (µ) length (µ) Chromosome morphology m M M m m sm m m m

4 Figure2. Ideogram of Salsola crassa subsp. turcomanica Salsola abarghuensis This species has chromosome number of 2n=18 (figure3). Among the total of 9 pair chromosomes of this species, 8 pairs are metacentric and 1 pair is submetacentric (table2). The longest chromosome is chromosome No. 1 that has the length of 5.66 µ and is metacentric and chromosome No. 9 that the shortest one has the length of 3.68 µ and is metacentric. The length of total chromosomes of this species equals to µ. According to the classification of Stebbines [11], karyotype group of this species was determined to be 1A. The karyotype formula of this species is as 4M+12m+ 2sm. The ideogram of chromosomes is illustrated in figure 4.

5 Figure3. Mitotic metaphase chromosomes of Salsola abarghuensis Chromosome No. Table1. Morphometric data on chromosomes of the diploid species Salsola abarghuensis (2n=18) Long Short total Pa-value arm(l) arm(s) chromosome L% (L/S) (µ) (µ) length (µ) Chromosome morphology m M m m m m M m sm

6 Figure4. Ideogram of Salsola abarghuensis Karyotype is chromosomes' morphological features which are observed in mitotic metaphase. Comparison of karyotype of different species of genus with population of species is carried out through comparison of their karyotype symmetry. The Salsola studied species have chromosome base number of X=9, and chromosome number is 2n=18. The karyotype of these species is somehow similar and there is no general difference in karyotype symmetry. Among plants, symmetric karyotypes are usually elementary and the main incline is toward being asymmetry. Salar et al. [12] studied some species of Salsola and reported chromosome number in Salsola crassa by 2n=18 (diploid) and with 9 pairs of metacentric chromosomes which is consistent with the present study in terms of chromosome number. Bakhshi Khaniki and Marouf (2006) also studied the karyotype of S. crassa subsp.turcomanica in Agh ghala and reported chromosome number of 2n= 36 (tetraploid) with 30 pairs of metacentric chromosome and 6 pairs of sub metacentric chromosomes. Difference in chromosome number and form of chromosomes can show different populations, varieties, subspecies and even different species. These should be carefully studied in terms of morphology on plant species with have different karyotypes in future studies. REFERENCES [1] Rechinger, K.H. 1997; Flora Iranica (Chenopodiaceae). No. 172, Akademische Druck U Verlagsanstalt. Graz Austria. [2] Stebbins, G.L Variation and evolution in plants. Clumbia University Press, New York. [3] Stuessy, T.F Cytology, Genetics and cytogenetics in plant taxonomy. Cloumbia University press, New York. [4] Bakhshi Khaniki, Gh. and E. Maroof Karyotypic study of some species of the genus Salsola in Golestan province. Pajouhesh and Sazandegi, 72: [5] Xiaowei, W., Zh. Yuejun and H. Junhua Karyotype of 4 species of Salsola L. in Xinjiang and their evolution. Acta Botanica Boreali-Occidentalia Sinica. 29(9):

7 [6] Zarei, Gh., F.A. Fallahian, M. Assadi and A.A. Masoumi Karyological study in Salsola abarghuensis. Pajouhesh va Sazandegi. 16(1): [7] Mirzadeh Vaghefi, S.S., A. Jalili, F.S. Ghasemi and S. Ashrafi Chromosome numbers of Paronychia kurdica and Salsola yazdiana. Iran. J. Bot. 20(2): [8] Gaffari, S.M Chromosome reports for some plant species from Iran. Iranian Journal of Botany14(1): [9] Peruzzi, L. and G. Cesca 2004: Chromosome numbers of flowering plants from Calabria, S Italy, II.- Willdenowia 34: [10] DiTomaso, J. M., Healy, E. A. 2007: Weeds of California and other Western States, Volume 1.- UCANR Publications 625. [11] Stebbins, G.L., Chromosomal evolution in higher plants. Edward Arnold, London. 216 p. [12] Salar, N., H. Madah Arefi, A. Nasirzadeh and M. Assadi Karyotypic study on some species of Salsola. Iranian Journal of Rangelands Forests Plant Breeding and Genetic Research. 11(4):

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