Cryptogamie, Algologie, 2015, 36 (4): 389-405 © 2015 Adac. Tous droits réservés Distribution of Charophytes from Iran with three new records of Characeae (Charales, Chlorophyta) Fariba NOEDOOST, Hossein RIAHI, Masoud SHEIDAI & Akram AHMADI* Faculty of Biological Sciences, Shahid Beheshti University, Tehran, Iran Abstract – The Charales, commonly known as stoneworts, are a group of highly complex green algae that comprise one extant family (Characeae) with six genera. The aim of this study was to collect Charophytes in eastern and north of Iran and check the distribution maps of species in Iran. Samples were collected from 103 localities and 7 species have been determined with Chara braunii Gm., Chara globata Mig. and Lamprothamnium papulosum (Wallr.) J. Gr. recorded for the first time in Iran. Although Chara vulgaris and Chara gymnophylla were reported as widespread in north and eastern Iran, specimens of Chara vulgaris were collected in a wide variety of habitats from most of the provinces rendering this taxa the most abundant Charophytes in Iran (88 populations). Other species were restricted to few locations: Chara braunii, a cosmopolitan species, was limited to two locations in north Iran. Chara globata was found in a single location (Targhrud Lake). Most specimens of Chara contraria and Chara connivens were collected from South West Iran (260-350 m elevation). Lamprothamnium papulosum, a rather uncommon species in Asia, was found in a single lake with marine water characteristics in northeast Iran. Charophytes / Characeae / Chara / Lamprothamnium / Taxonomy / Distribution INTRODUCTION The Characeae, commonly known as stoneworts, are a large group of macrophytic green algae that live submerged in slow running and standing waters. Characeae most often occur in freshwater but they can tolerate hyper saline conditions (García & Chivas, 2006) over muddy and sandy substrate (Krause, 1997). Characeae spread rhizoids through the sediments and are able to form widespread monospecific underwater meadows in a wide diversity of habitats (Stewart & Church, 1992; Fritsch, 1935). The organization of the plant and life cycle of the Characeae are distinctive (Dangeard, 1933) differing in their complexity from other green algae (Wood & Imahori, 1965). The Characeae are oogamous, have motile sperm cells, and possess sterile cells surrounding their antheridial filaments and their oogonia (Bold & Wynne, 1985). There are six extant genera organized in tribe Chareae (Chara, Lamprothamnium, Lychnothamnus, Nitellopsis) and tribe Nitelleae (Nitella, Tolypella) (Wood & Imahori, 1965). Chara and Nitella encompass the majority of species in the family while the other genera comprise a few (Lamprothamnium and Tolypella) or a single species (Lychnothamnus and Nitellopsis). This classification was based on morphological characters (Wood & Imahori, 1965). The species and infraspecific * Corresponding author: [email protected] doi/10.7872/crya/v36.iss4.2015.389 390 F. Noedoost et al. concepts have been determined on the basis of vegetative morphology and characteristic of the oospore wall ornamentations (Leitch et al., 1990). However, because of a large amount of variations in wall ornamentation and differences in developmental characteristics, using the oospore as the sole taxonomic criterion for separating species is in some cases very speculative. Additionally, despite numerous studies that have documented the differences between oospores of recognized taxa within the genus Chara, variations within and among populations of the same species are still not well documented (Soulié-Marschë 1989; John et al., 1990; Leitch et al., 1990; Ray et al., 2001). The taxonomic value of oospore characters depends upon their morphological constancy within species. The advantage of using oospore wall ornamentation is apparently this character less affected by environmental factors than the previously mentioned ones (Proctor, 1975). Our study confirms the previously published ornamentation patterns for Iranian species (Ahmadi et al., 2012 c), and adds new findings on C. globata that have not been documented before by SEM. The most recent report from the western and central part of Iran has been published by Ahmadi et al. (2012 a, b) who recorded eighty localities for eighty two populations ascribed 13 species belonging to three genera. In the present study, we investigated one hundred and three localities in eastern and northern Iran for the presence of charophytes and report our observations providing illustrations, vegetative and oospore characteristics of collected taxa and discuss distribution of Iranian charophytes. Diagnostic features Species of Lamprothamnium in the family Characeae are remarkably tolerant to salinity, living in brackish, saline and hyper saline aquatic habitats (Wood & Imahori, 1965; García & Chivas, 2004, 2006). All members of the genus Lamprothamnium are characterized by ecorticate internodes and branchlets (similar to C. braunii), but differ by the presence of downward pointing stipulodes, placed directly below each branchlet whorls and verticillate bract cells inserted at angles of 45-90° to the axis of branchlet (Groves, 1916). The shoots of species of Lamprothamnium often have a dense “fox-tail” appearance because the upper internodes are short and the branchlets, stipulodes and bract cells overlap. Many species produce a calcified casing on the oospore and frequently develop distinctive, spherical white bulbils at the rhizoid filament (Fritsch, 1935). These bulbils are full of starch grains, and allow species to persist when it is unable to photosynthesize, and they regenerate when the vegetative axis is uprooted or destroyed (Schmieder et al., 2006). Most of the species of Chara occuring in the Northern Hemisphere have internodes covered by a cortex of smaller, linearly aligned cells (Krause, 1997). MATERIALS AND METHODS Samples were collected from 103 localities (April to September 2012 and 2013) from north and eastern of Iran and 125 populations identified within 7 species were recognized (details of localities are given in Table 1). The specimens were collected by hand and with the help of a grapnel at various depth. Morphological Distribution of Charophytes from Iran 391 observations were carried on dried samples as herbarium specimens. Dried specimens were examined under 10×, 20× and 30× with a stereomicroscope. The voucher specimens are kept in the herbarium of Shahid Beheshti University (HSBU) Tehran and the voucher numbers are given in Table 1. The identification of specimens was done by using descriptions provided by Wood and Imahori (1964, 1965), Migula (1897) and Caisova and Gabka (2009). Measurement of oospores: The oospores of species were examined on fifteen individuals sampled randomly and the spiral cells were taken off and removed. The oospore characteristics (length, width, number of striae and fossa-breath) were measured under a stereomicroscope at magnification 400× (Mandal et al., 2008). The oospores were treated using the method of Urbaniak (2011) for the preparation of oospore for light microscope or SEM investigation. Acetolized cleaned oospores were mounted on stubs having double-sided adhesive tape. The oospores were coated with gold-palladium by a sputter-coater and observed with a KYKY-EM3200 SEM. Microphotographs were taken at different magnifications. Table 1. Localities of Chara species with their voucher numbers and sampling date C. braunii Gilan Province 37°05’24” N 50°09’20” E 56 HSBU-2011496 12.08.2012 Mazandaran Province 36°33’48” N 53°05’09” E 37 HSBU-2011500 10.08.2012 C. connivens Khuzestan Province 30°34’18” N 50°13’13” E 286 HSBU-2011465 13.05.2012 C. contraria Khuzestan Province 30°36’24” N 59°09’12” E 266 HSBU-2011461 24.04.2012 30°37’34” N 50°07’54” E 272 HSBU-2011462 24.04.2012 30°36’59” N 50°09’06” E 354 HSBU-2011463 24.04.2012 30°34’15” N 50°12’30” E 278 HSBU-2011466 26.04.2012 C. gymnophylla var. gymnophylla f. condensata Gilan Province 36°42’54” N 49°51’21” E 1463 HSBU-2011522 14.8.2012 C. gymnophylla var. gymnophylla f. gymnophylla Semnan Province 35°37’13” N 53°21’40” E 1284 HSBU-2011477 12.07.2012 Isfahan Province 33°36’34” N 51°42’23” E 1697 HSBU-2011403 15.07.2012 Mazandaran Province 36°33’48” N 53°05’09” E 37 HSBU-2011508 10.08.2012 Kerman Province 30°37’31” N 57°00’38” E 2222 HSBU-2011487 11.07.2012 Gilan Province 36°46’32” N 49°44’19” E 1178 HSBU-2011495 12.08.2012 36°42’23” N 49°48’54” E 1547 HSBU-2011497 13.08.2012 36°40’57” N 49°34’52” E 1048 HSBU-2011499 13.08.2012 392 F. Noedoost et al. Table 1. Localities of Chara species with their voucher numbers and sampling date (continued) C. gymnophylla var. rohlenae f. elongate Isfahan Province 31°43’02” N 51°48’33” E 2247 HSBU-2011405 13.07.2012 31°51’21” N 51°36’02” E 2236 HSBU-2011408 13.07.2012 Tehran Province 35°42’50” N 52°39’57” E 1809 HSBU-2011410 13.08.2012 35°44’11” N 52°42’10” E 1900 HSBU-2011412 12.08.2012 North Khorasan Province 30°17’43” N 57°13’25” E 1465 HSBU-2011457 1.07.2013 30°11’53” N 57°27’56” E 2194 HSBU-2011486 11.07.2012 Kerman Province 30°30’10” N 57°16’16” E 2008 HSBU-2011488 12.07.2012 Mazandaran Province 36°25’45” N 53°08’49” E 154 HSBU-2011505 12.08.2012 36°21’58” N 53°10’33” E 272 HSBU-2011507 12.08.2012 Semnan Province 36°11’26” N 54°23’23” E 1137 HSBU-2011475 18.07.2012 Yazd Province 31°43’45” N 54°08’38” E 1608 HSBU-2011516 9.07.2012 C. gymnophylla var. rohlenae f. rohlenae Gilan Province 36 °4’′23” N 49°48’54” E 1548 HSBU-2011498 13.08.2012 Mazandaran Province 36°11’02” N 51°43’54” E 2161 HSBU-2011512 11.08.2012 Kerman Province 30°36’06” N 56°58’47” E 2107 HSBU-2011479 11.07.2012 30°11’46” N 57°26’54” E 2292 HSBU-2011483 11.07.2012 29°5’59” N 57°26’10” E 2356 HSBU-2011485 11.07.2012 C.