Polyploidisation—and, additionally, agmatoploidy (concerted fission of chromosomes) in some plant groups—have significantly contributed to the diversification of alpine plant species. Both processes ...have driven the diversification of
Luzula
sect.
Luzula
, leading to a number of different karyotypes, rendering it one of the most intricate plant groups in the Alps. For the Eastern Alps eight species with six karyotypes were reported, but their distribution is insufficiently known. A herbarium revision of 1044 specimens revealed that
L. alpina
,
L. campestris
,
L. exspectata
,
L. multiflora
and
L. sudetica
are widespread across the Eastern Alps;
L. exspectata
is thus new for the Northern Alps and new for Germany, France and possibly Croatia.
Luzula divulgata
is distributed in the easternmost Alps and adjacent areas, with only a few indications for the western Eastern Alps.
Luzula divulgatiformis
is new for the Alps where it was recorded in the Southern Alps and southerly adjacent areas.
Luzula campestris
,
L. divulgata
and
L. divulgatiformis
are distributed from lowlands to the montane belt,
L. alpina, L. exspectata
and
L. sudetica
are high-elevation species and
L. multiflora
occurs from lowlands to the alpine belt. Additionally, we estimated genome size (GS) and karyotypes for 20 populations and revealed four karyotypes corresponding to three ploidy levels. The GS of diploid
L. exspectata
and
L. sudetica
was 0.83 pg DNA, tetraploid
L. alpina
had a double (1.63 pg) and hexaploid
L. multiflora
a triple (2.48 pg) GS. Our study underlines the importance of large-scale herbarium revisions of intricate taxa, combined with cytological methods, even in well-studied mountain areas such as the Alps and poses new hypotheses regarding the evolution of this polyploid–agmatoploid group.
Luzula sect. Luzula is one of the taxonomically most intricate groups of angiosperms, where diversification is mostly driven by true polyploidy and agmatoploidy (fission of chromosomes) leading to ...three different karyotypes (whole chromosomes — AL, half-sized chromosomes — BL and quarter-sized chromosomes — CL). Morphologically, the taxa are often difficult to distinguish, and genome size data coupled with karyological investigations are currently the most reliable means for their identification. For the Balkan Peninsula, one of the botanically least studied areas of Europe, ten taxa from this section have been reported, but little is known about their distribution. We here estimated the nuclear DNA amount (genome size, GS) using interphase-peak DNA image cytometry and counted the chromosomes for 33 populations of five species of Luzula sect. Luzula mostly from mountainous areas of the Balkan Peninsula and the adjacent southeastern Alps. Five taxa have been confirmed, of which L. divulgatiformis is new for Croatia and L. exspectata for Macedonia and Serbia. The most common species in the Dinaric mountains appears to be diploid (2n = 12 AL) L. taurica, for which the GS (2C = 0.83 pg DNA, fitting well in the range of previously determined values of diploid taxa) has been determined for the first time. The GS and karyotypes of other taxa (L. campestris, L. divulgatiformis, L. exspectata, L. multiflora subsp. multiflord) correspond well to previously published values. An identification key for the Balkan taxa of Luzula sect. Luzula is also included.
Luzula sect. Luzula is the most taxonomically diverse group within the genus. It displays a wide range of chromosome numbers due to polyploidy and agmatoploidy. In eight taxa of the section from ...Slovenia, NE Italy and S Austria, chromosomes were counted and the nuclear DNA amount, expressed as the C-value, was measured in root tip cells of seedlings, using interphase-peak DNA image cytometry. Previously known karyotypes were confirmed (Luzula campestris (L.) DC. subsp. campestris: 2n = 12 AL; L. multiflora (Ehrh.) Lej. subsp. multiflora: 2n = 24 AL and 2n = 36 AL; Luzula divulgata Kirschner: 2n = 24 AL; L. sudetica (Willd.) Schult.: 2n = 48 CL; and L. alpina Hoppe: 2n = 12 AL + 24 BL), and a new karyotype 2n = 24 BL was found in the region. Two new taxa were discovered and described: L. exspectata Bačič & Jogan (2n = 24 BL) and L. divulgatiformis Bačič & Jogan (2n = 24 BL). The 2C-value proved to be similar in diploid (L. campestris) and agmatoploid taxa (L. sudetica, L. exspectata, L. divulgatiformis) and ranged from 0.83 to 0.97 pg DNA. In the case of true polyploidy, the nuclear DNA amount approximately doubled in the tetraploids L. divulgata and L. multiflora (2C-value 2.09 and 1.88 pg, respectively) and tripled in hexaploid L. multiflora (2C-value 2.73 pg). The 2C-value of 2.06 pg of the partial agmatoploid L. alpina approximately equals the DNA amount in true tetraploids.
The amount of nuclear DNA, expressed as the
C-value, was estimated for 13 marine halophytic plant species from six families. Plant material was collected in the nature reserve of the Strunjan saltpan ...in the Northern Adriatic and comprised all halophytic species inside the investigated area. Reproductive region of the shoot or root tips of halophytes were dissected, nuclei were Feulgen stained and 2
C-values were measured by DNA image cytometry as follows:
Crithmum maritimum (4.38
pg
DNA),
Artemisia caerulescens (6.43
pg),
Aster tripolium (21.43
pg),
Inula crithmoides (3.63
pg),
Atriplex portulacoides (1.83
pg),
A. prostrata (1.51
pg),
Salicornia europaea (2.75
pg),
Salsola soda (2.62
pg),
Sarcocornia fruticosa (5.91
pg),
Suaeda maritima (2.11
pg),
Limonium angustifolium (5.06
pg),
Puccinellia palustris (8.15
pg) and
Ruppia cirrhosa (4.65
pg). With the exception of the
C-value estimate for
A. caerulescens, which has been listed in the Plant DNA
C-values Database, the
C-values represent the first estimates for all the examined species. In addition, the
C-value for
R. cirrhosa is also the first report for the family Ruppiaceae. The investigated halophytes had a smaller genome size compared to other known
C-values for species within a particular family and also when compared to the mean values of dicots and monocots. The study also showed that halophylic annuals have a smaller genome size (2.49
pg) than perennial ones (7.45
pg
DNA).
Članek obravnava 40 enokaličniških taksonov, ki so v slovenskem Rdečem seznamu (1989) navedeni v kategoriji nezadostno znanih vrst. Vrste so podrobno obravnavane glede na rastišče, razširjenost in ...naravovarstveni status v sosednjih deželah in pri nas. Pri predlogu kategorije ogroženosti je bila upoštevana redkost vrste, novejše potrditve uspevanja pri nas, potencialna ogroženost habitatov in upadanje populacij. Za 22 vrst so predlagane glavne kategorije ogroženosti. 5 vrst ostaja nezadostno znanih, ker so taksonomsko problematične ali pa je na voljo premalo podatkov o njihovi razširjenosti. 7 vrst je bilo za Slovenijo napačno navedenih, druge pa uspevajo pri nas le prehodno ali pa so naravovarstveno nepomembne oz. neogrožene.
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