Determination of ploidy and nuclear DNA content in populations of Atriplex halimus (Chenopodiaceae)

Abstract

Nuclear DNA contents were determined by flow cytometry for 20 populations of the perennial C 4 shrub Atriplex halimus L. (Chenopodiaceae) originating from the Mediterranean basin and Fuerteventura (Canary Islands). Two populations were also analysed for chromosome number: one (from Ibiza, Spain), with a 2C nuclear DNA content of 2.40 pg, was shown to be diploid (2 n = 2 x = 18), whilst the other (from Sicily, Italy), with 5.11 pg, was tetraploid (2 n = 2 x = 36). With respect to nuclear DNA content, two groups of populations were detected, diploids with 2.40-2.44 pg and tetraploids with 4.77-5.13 pg. The diploid populations were mainly from the western Mediterranean (Spain and France) and Fuerteventura, whereas tetraploids were generally, but not exclusively, from more arid areas in North Africa and the eastern Mediterranean. In general, the diploid and tetraploid populations corresponded to the subspecies halimus and schweinfurthii , respectively. For certain populations having morphologies intermediate between those considered typical of these two subspecies, nuclear DNA contents showed them to be tetraploid. There was significant variation in nuclear DNA content among the tetraploid populations, with greater values in the more easterly populations.

Morphology and chromosome numbers of <i>Gongronema latifolia</i> benth. clones from Nigeria

“…The occurrence of these polyploids may be attributed to failure of normal mitotic division in a diploid body cell leading to increased sets of chromosomes (Uguru, 2004) or may be due to the presence of more F % =Ratio of short arm to the total chromosome length; ST =Subtelocentric; SM = Submetacentric; M = Metacentric; SD = Standard deviation; S= Standard error; Cv% = Percentage coefficient of variation than one nucleus per cell (Partanen, 1963). Polyploidy in some instances is advantageous as it affects plant part sizes like larger leaf areas, flowers and fruits (Walker et al 2005;ElFerchichi et al 2006;Samiha et al 2009). The higher number of viable seeds per follicle and matured follicles per inflorescence in IMS-20-NJIABA and AKS-33-EKPENE EDIENE may be attributed to the highly stable nature of diploid species in contrast to polyploids that are often plagued with instability and sterility (Uguru, 2004).…”

The tolerance of Atriplex halimus L. to environmental stresses

“…For example, halimus has a more-erect habit and is smaller (0.5-2.0 m tall compared to 1.0-3.0 m for schweinfurthii). Sub-species schweinfurthii grows in arid or saline zones (North Africa, the eastern Mediterranean basin, the Middle East and western Asia) and halimus in semi-arid, less-saline areas (in the western Mediterranean basin and Macaronesia) (Le Houérou, 1992;Walker et al, 2005). According to Walker et al (2005), the sub-species halimus and schweinfurthii are diploid (2n=2x=18) and tetraploid (2n=4x=36), respectively.…”

“…Sub-species schweinfurthii grows in arid or saline zones (North Africa, the eastern Mediterranean basin, the Middle East and western Asia) and halimus in semi-arid, less-saline areas (in the western Mediterranean basin and Macaronesia) (Le Houérou, 1992;Walker et al, 2005). According to Walker et al (2005), the sub-species halimus and schweinfurthii are diploid (2n=2x=18) and tetraploid (2n=4x=36), respectively. Perennial plant species which are exposed to extreme conditions (heat, drought, salinity, high light intensity) in arid and semi-arid zones possess morphological, anatomical, biochemical and physiological adaptations.…”

“…It has been planted for animal fodder and physical stabilisation of the soil throughout the arid and semi-arid zones of the Mediterranean basin and beyond. A. halimus occurs naturally throughout Eurasia, from Macaronesia, through the Mediterranean basin and into the Middle East and western Asia: including Portugal, France, Spain, Italy, Greece, Turkey, Cyprus, Israel, Syria, Lebanon, Jordan, Tunisia, Morocco, Algeria, Libya, Egypt and Saudi Arabia (Le Houérou, 1992;Al-Turki et al, 2000;Walker et al, 2005). It grows in zones of low annual rainfall (R) and high potential evapotranspiration (PET): many of these can be classified as arid (R = 100-400 mm, R:PET = 0.06-0.28) or semi-arid (R = 400-600 mm, R:PET = 0.28-0.45).…”

FLOW CYTOMETRIC ANALYSIS OF NUCLEAR DNA BETWEEN OKRA LANDRACES (<i>ABELMOSCHUS ESCULENTUS</i> L.)

“…Genome size of different animals e.g Dairy goat (Fletcher et al, 2013) as well as different, plants has been estimated by flow cytometry like Pinus (O'Brien et al, 1996), Lemon (Iannelli et al, 1998), Arachis hypogeal (Temsch and Greilhuber, 2000), Musa (Roux et al, 2003), Atriplex halimus (Walker et al, 2005), Consolea (Negron-Ortiz, 2007), Vicia faba (Kovarova et al, 2007) Cactus (Lema-Ruminska, 2011), Coffea (Clarindo et al, 2012), Calendula species (Nora et al, 2013), Eryngium (Tavares et al, 2013), Lathyrus (Ochatt et al, 2013) and Phragmites austalis (Nakagawa et al, 2013).…”