http://ebd06.ebd.csic.es/pdfs/Medrano.&.Herrera.2008.Ann.Bot.pdf

Geographical structuring of genetic diversity across the whole distribution range of Narcissus longispathus, a habitat-specialist, Mediterranean narrow endemic.

The taxonomy of all species of Narcissus (Amaryllidaceae), an important horticultural crop, has not been investigated recently. As a new approach, genome size was determined by flow cytometry with propidium iodide from 375 accessions. The somatic nuclear DNA contents (2C) were shown to range from 14 to 38 pg for the diploids. Narcissus assoanus and N. gaditanus are, based on their nuclear DNA content, removed from section Apodanthi and placed in a new section Juncifolii. The different ploidy levels and species involved were entangled for N
 . “fernandesii” s.l. and a new allotetraploid form is named here. Section Pseudonarcissus was much more heterogeneous in nuclear DNA content than expected. Sixty-five accessions of N. pseudonarcissus possessed, with 23.7 pg, similar amounts of DNA. However, several species from this section were clearly distinctive in nuclear DNA content. It runs from the diploid N. primigenius with 21.7 pg to the also diploid N. nevadensis with 38.2 pg. Also N. abscissus and N. moleroi are with about 26 pg clearly different from N. pseudonarcissus. For the first time, in 11 accessions, hexaploidy was found in N. pseudonarcissus ssp. bicolor. A new section Nevadensis with 30–39 pg of nuclear DNA was split off from the section Pseudonarcissus with now 21–27 pg. A nonoploid N. dubius with 96.3 pg has by far the highest amount of nuclear DNA and can be calculated to have the highest ploidy ever reported in Narcisssus. The total number of Narcissus species was determined as 36, nine more than in Flora Europaea and they were divided up in two subgenera and 11 sections. Flow cytometry is shown to produce easily obtainable and original systematic data that lead to new insights. Genome size or C-value turns out to be one of the most salient features to define the status of the species in the genus Narcissus.

/pdf/the-systematic-value-of-nuclear-dna-content-for-all-species-4n5z9jlx44.pdf

The systematic value of nuclear DNA content for all species of Narcissus L. ( Amaryllidaceae)

Evolution of alkaloid biosynthesis in the genus Narcissus.

Premise of research. Determination of species boundaries is essential for understanding and preserving biological diversity, yet it remains a difficult task for many plant lineages. Population genetics approaches explicitly taking into account the geographic context of processes driving population divergence and speciation may help to identify species boundaries in complex groups. Here, we adopt this approach to investigate genetic boundaries in an endemic group of trumpet daffodils (Narcissus, section Pseudonarcissi) whose taxonomic distinctiveness remains controversial.Methodology. We analyzed amplified fragment length polymorphism markers from a total of 36 populations (526 individuals) spanning the group’s entire distribution range in the southern Iberian Peninsula. To identify the most likely number of distinct genetic groups, model- and nonmodel-based methods (Bayesian, principal coordinates, and neighbor-joining classification) were applied. Effects of long-term historical divergence were dissected...

http://ebd06.ebd.csic.es/pdfs/Medrano.et.al.2014.Int.J.Plant.Sci.pdf

Population Genetics Methods Applied to a Species Delimitation Problem: Endemic Trumpet Daffodils (Narcissus Section Pseudonarcissi) from the Southern Iberian Peninsula

Narcissus longispathus (Amaryllidaceae) is a perennial geophyte and a Mediterranean narrowly endemic species. At dispersal time, N. longispathus seeds are dormant and have underdeveloped embryos. This work aimed to determine requirements for dormancy break and germination and to compare dormancy traits with those of the two endemic Iberian congeners. Phenology of embryo growth and germination were studied by regularly exhuming seeds sown in nearnatural conditions. Temperature and light requirements for embryo growth, breaking of dormancy and germination were determined by incubating seeds under controlled laboratory conditions. Mean embryo length in fresh seeds was 1.50mm, and embryos had to grow to 3.80mm before radicle emergence. Embryos grew to full size and seeds germinated when they were warm stratified for 2 months (optimum 1month at 20/78C þ 1month at 15/48C), then cold stratified at 58C for 2 months, and finally incubated at cool temperatures (15/48C) for 30d. However, in seeds only subjected to either warm or cold stratification, the embryos hardly grew and did not germinate. In natural conditions, the embryos elongate in autumn‐winter, and in late winter‐early spring (March) almost all radicles and seedlings emerged. Velocity of embryo growth and germination percentages increased with seed storage duration. Seeds of N. longispathus have non-deep complex morphophysiological dormancy (MPD). This is the first report of such a level of MPD in Narcissus. Our data suggest that non-deep complex MPD may have been derived from intermediate complex MPD in the section Pseudonarcissi.

http://ebd06.ebd.csic.es/pdfscazorla/Herranz.et.al.2013.Seed.Sci.Res.pdf

Non-deep complex morphophysiological dormancy in Narcissus longispathus (Amaryllidaceae): implications for evolution of dormancy levels within section Pseudonarcissi

http://ebd06.ebd.csic.es/pdfscazorla/Rios-Ruiz.et.al.1999.BotJLinnSoc.pdf

Segundo Ríos-Ruiz

Papers

Three new species of Narcissus L. subgenus Ajax Spach (Amaryllidaceae), restricted to the meadows and forests of south-eastern Spain