Potamogeton ×jutlandicus,a binominal for the hybrid between P. lucens and P. praelongus (Potamogetonaceae)

Because the name Potamogeton ×babingtonii has been synonymised with P. ×angustifolius, no valid binominal exists for the hybrid P. lucens×praelongus. A morphological and anatomical study presented here demonstrates that specimens regarded by Hagström as Potamogeton ×babingtonii f. danicus really represent the hybrid between P. lucens and P. praelongus. As a consequence, a new binominal for this hybrid is introduced and its basionym Potamogeton ×babingtonii f. danicus is lectotypified. Morphological and anatomical characters of Potamogeton ×jutlandicus nom. nov. (=P. lucens×praelongus) are provided and its taxonomic delimitation is discussed.     

A new hybrid horsetail Equisetum×lofotense (E. arvense×E. sylvaticum,Equisetaceae) from Norway

On the Island of Austvågøya (Lofoten, Norway), a new hybrid horsetail (E. arvense×E. sylvaticum) was found, which is described as E.×lofotense. Its macro‐ and micro‐morphological characters are discussed and compared with the similar hybrid E.×mildeanum (E. pratense×E. sylvaticum) with which it shares the E. sylvaticum parentage. The hybrid nature is verified by its completely aborted spores, and the micro‐morphology of the stem ridges and stomata, illustrated by SEM images, confirm the proposed origin. An overview of all known hybrids in the genus Equisetum is given and critically commented. It becomes evident that in subgenus Equisetum E. arvense is the species most frequently involved in hybridization events.     

Recurrent hybridisation events between Primula vulgaris,P. veris and P. elatior (Primulaceae,Ericales) challenge the species boundaries: using molecular markers to re‐evaluate morphological identifications

Three Primula species, Primula vulgaris, P. veris and P. elatior, have been objects of fascination for gardeners and botanists over several centuries. The species are able to hybridise, and where they co‐occur, hybrids are commonly found. In Denmark, Møns Klint on the island of Møn and Købelev Skov on Lolland are examples of localities where all three species occur and where the hybrids P. × digenea, the hybrid between P. vulgaris and P. elatior, and P. × polyantha, the hybrid between P. veris and P. vulgaris, can also be found. To investigate relationships between the species and their hybrids, we sampled 168 specimens from 10 geographical locations and subjected them to genetic analysis. The samples were also identified based on morphological traits: primarily inflorescense structure, the size, shape, colour and markings of corolla and leaf basis, leaf blade texture and hairiness. After identifying species‐specific SNPs in the Internal Transcribed Spacer sequence, these were used to resolve species and hybrid boundaries and status through a cleaved amplified polymorphic sequence assay. Polymorphisms in the chloroplast trnL sequence were used as a high‐throughput marker and used to determine the maternal parent of hybrids. Ten simple sequence repeat markers were applied to obtain further insight into the genetic makeup of the accessions using structure and Introgress, providing information of genetic variability within and between populations. Our results indicated that backcrossing of P. × digenea hybrids with parental species has occurred, and that many of the P. × digenea sampled were later‐generation hybrids rather than F₁s. Analyses of P. × polyantha specimens show mostly the expected pattern for primary hybrids but indications of P. veris ancestry of a P. vulgaris plant was discovered. Our results further indicate that some of the specimens initially identified as P. elatior include P. vulgaris among their progenitors and thus challenge currently accepted species boundaries.     

Stipa×brozhiana (Poaceae) nothosp. nov. from the western Pamir Alai Mts (middle Asia) and taxonomical notes on Stipa×tzvelevii

Stipa ×brozhiana M. Nobis nothosp. nov. (Poaceae) is described and illustrated. The taxon belongs to sect. Smirnovia Tzvel. and originated from the hybridization of species belonging to sect. Smirnovia and Barbatae Junge. Stipa ×brozhiana is morphologically close to Stipa lipskyi Roshev., but is easily distinguished by its much shorter hairs on the seta, thinner, uni‐ or indistinctly bigeniculate awns, differently shaped callus and longer ligules of vegetative shoots. Characters distinguishing S. ×brozhiana from the parental species and other similar hybrid taxa belonging to sect. Smirnovia and occurring in the Pamir Alai Mts are discussed. In addition, the taxonomical status of S. ×tzvelevii Ikonn. pro sp., another taxon that has originated from hybridization between species belonging to sect. Smirnovia and Barbatae, is discussed. The taxon was originally described as a distinct species, but is now considered to be the hybrid S. caucasica×S. orientalis. The main characters distinguishing S. ×tzvelevii from parental species are given.     

A new natural allotriploid,Lycoris × hubeiensis hybr. nov. (Amaryllidaceae), identified by morphological,karyological and molecular data

A new natural hybrid, Lycoris × hubeiensis K. Liu, is confirmed and described based on morphological, karyological and molecular data. The new natural hybrid displays remarkable morphological differences relative to the putative parents L. radiata (2n = 22 = 22A) and L. aurea (2n = 14 = 8m + 6T), and has a karyotype of 3n = 29 = 4m + 22A + 3T. Two chloroplast intergenic regions of ndhF‐rpl32R and rpl32F‐trnL were sequenced with three haplotypes found in the three taxa. The putative hybrid and L. radiata shared the same haplotype (H1), while L. aurea had two other haplotypes (H2 and H3). Combined with the morphological, karyological and molecular data, we conclude that the hybrid is an allotriploid with L. radiata being the maternal parent offering an unreduced gamete and L. aurea being the male parent.     

Chloroplast evidence for the multiple origins of the hybrid Potamogeton × fluitans

Previous studies of Potamogeton × fluitans Roth. have supported the putative origin of this taxon as a result of hybridization between Potamogeton lucens L. and Potamogeton natans L. In the British Isles P. × fluitans is restricted to only a few sites, while both its parents are relatively common. Previous studies have shown that most of these hybrid populations are monomorphic, with the exception of the Moors River, in Hampshire and Dorset, where multiple genotypes have been identified. This is despite the fact that here the hybrid grows in the absence of one its parents, P. lucens. In this study, species-specific differences in the TrnL (UAA) chloroplast region, a maternally inherited marker, were used to identify the original seed-bearing parent of the hybrids within this river system. It was shown that both species have been maternal parents in the creation of this hybrid population.     

First record of Potamogeton×salicifolius for Italy,with isozyme evidence for plants collected in Italy and Sweden

Abstract

Potamogeton×salicifolius, a hybrid between P. lucens and P. perfoliatus, is identified as a new taxon for Italy. This is the first record of this hybrid from southern Europe. The Italian sample was studied in cultivation and compared with a living specimen of P.×salicifolius from Sweden, where the hybrid is rather widespread. In addition to morphological features, the most compelling evidence for the hybrid origin of these plants came from the isozyme analysis. The additive “hybrid” banding patterns of the five enzyme systems studied indicate inheritance from P. lucens and P. perfoliatus. The distribution of this hybrid in Europe coincides with the areas most severely affected by the Late Pleistocene glaciation. The relationships between environmental conditions, history of the habitat and rise of hybrids are discussed.     

Morphometric and population genetic analyses elucidate the origin,evolutionary significance and conservation implications of Orchis × angusticruris (O. purpurea × O. simia), a hybrid orchid new to Britain

We report the first confirmed occurrence in Britain of Orchis × angusticruris Franch. ex Rouy, a hybrid between two closely related orchid species of anthropomorphic Orchis (O. purpurea Huds. × O. simia Lam.) that hybridize frequently in Continental Europe. Seven individual hybrids, most likely F1 plants representing a single interspecific pollination event, first flowered with both parents in May 2006 at a nature reserve in the Chiltern Hills near Goring, Oxfordshire. Univariate and multivariate morphometric analyses (43 characters plus 12 indices), internal transcribed spacer sequencing, plastid microsatellites and amplified fragment length polymorphism (AFLP) analyses together readily separate the parents and confirm that O. purpurea was the ovule parent and O. simia the pollen parent, presumably reflecting the greater frequency and/or later flowering period of the latter at the site. This study reinforces a more general observation that, in most orchids, the ovule parent contributes substantially more to the hybrid phenotype than does the pollen parent, perhaps reflecting cytoplasmic inheritance. In contrast, the hybrids are placed closer to O. simia than to O. purpurea in the AFLP tree. Apparently recent arrivals, the few O. purpurea plants at Goring contrast genetically with the two other small populations of this species known in the Chilterns, but rather are consistent with relatively uncommon Continental populations. This suggests that the plants may have been deliberately introduced at Goring by man, although transport from the Continent in high‐level air currents cannot be ruled out. The Goring population of O. simia is likely to have become genetically impoverished through (1) preferential removal of many relatively fit plants to herbaria in the 19^th century and/or (2) a catastrophic population crash in the first half of the 20^th century. However, both our re‐examination of herbarium specimens and our population genetic data indicate past hybridization among anthropomorphic Orchis species occurring naturally in the Chilterns. Thus, we tentatively recommend retention of the hybrid plants at Goring, despite their likely anthropogenic origin from Continental material and the partial viability of their pollen and seeds, which offers opportunities for future introgression. Although the Goring hybrids broadly resemble morphologically O. militaris, another anthropomorphic Orchis still found at two Chiltern localities, sufficient morphological and molecular differences were observed to strongly refute our initial hypothesis that O. militaris could have originated through hybridization between ancestors that resembled O. purpurea and O. simia. The comparatively complex genetic properties evident in both O. simia and O. purpurea merit further study. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 157 , 687–711.     

哀牢山兜兰,中国兰科一新天然杂种

报道了中国云南省兰科（Orchidaceae）兜兰属（Paphiopedilum）一新天然杂交种：哀牢山兜兰（Paphiopedilum×ailaoshanense B. Liu & S. P. Chen）。哀牢山兜兰与白旗兜兰（P. spicerianum）和沧源兜兰（P. gratrixianum var. cangyuanense）近缘,与前者的区别在于哀牢山兜兰花梗和子房有毛,中萼片带紫色晕以及紫色斑点,花瓣上侧暗绿色带紫色晕,下侧黄绿色;与后者的区别在于中萼片具1条宽阔的紫褐色中带,退化雌蕊紫色。哀牢山兜兰与天然杂种泸水兜兰（Paphiopedilum×lushuiense）相似,而哀牢山兜兰的中萼片下部边缘不后卷,近基部具紫红色晕,合萼片具2条明显紫色粗脉,花瓣匙形,上边缘波状,长6.0~6.2 cm,唇瓣长5.0~5.5 cm。为厘清哀牢山兜兰,沧源兜兰及白旗兜兰之间的关系,基于3个叶绿体基因片段（matK、rbcL、trnL）,构建了兜兰属部分植物系统发育树。鉴于形态和分子数据,认为哀牢山兜兰是天然杂交种。凭证标本存放于福建农林大学标本馆。     

When interspecific prezygotic barriers break down: hybridization between two Potamogeton species (P. wrightii and P. perfoliatus) and comparison of the artificial and natural hybrids

Interspecific hybridization played an important role in speciation and evolution of angiosperms. Although the widespread occurrence of natural hybrids in the genus Potamogeton has been studied intensively, few successful experimental hybridization studies have been reported in this genus. In the present study, critical experimental hybridization was conducted using Potamogeton?×?intortusifolius, a natural hybrid widely distributed in China, and its parents (P. perfoliatus and P. wrightii). The absence of prezygotic barriers between P. wrightii and P. perfoliatus was observed, which contributes to the frequent hybridization of these species in nature. The pollen tube growth rates of P. perfoliatus were much faster than those of P. wrightii in the style of that species. However, the conspecific pollen tubes were competitively advantageous in P. perfoliatus styles. The interspecific hybridization could be applied bidirectionally, and 28 F1 hybrid individuals were successfully obtained from P. wrightii?×?P. perfoliatus, despite the low germination possibility of the hybrid seeds. Both the artificial and natural hybrids exhibited intermediate morphological characters but presented much lower fertility. The sterility of P.?×?intortusifolius is mainly due to its low female fitness. However, the offspring from P. wrightii?×?P.?×?intortusifolius indicated the potential for backcrossing in nature. This is the most successful attempt at artificial hybridization in this genus so far. The possible route for restoration of fertility and the fitness of the hybrids are also discussed in this paper.     

Using DNA‐based techniques to identify hybrids among linear‐leaved Potamogeton plants collected in China

Abstract It is well known that interspecific hybrids occur in the genus Potamogeton. The linear‐leaved Potamogeton species commonly have highly variable morphological characteristics. Their hybrids often show similar vegetative characters to their parental species and their identification based solely on morphology is not always conclusive. In order to clarify whether there are any hybrids from the linear‐leaved Potamogeton plants collected in China, we used internal transcribed spacers (ITS) of nuclear ribosomal DNA and chloroplast rbcL gene sequences to identify the hybrids. Using ITS sequence additivity, we identified four hybrids, namely P. orientalis (P. pusillus×P. oxyphyllus), P. pusillus×P. berchtoldii, P. foliosus×P. octandrus, and P. cristatus×P. octandrus. The latter three hybrids should be considered as new hybrids in Potamogeton. The maternal parents of the four hybrids were confirmed using chloroplast rbcL gene sequences.     

860. BOMAREA × CANTABRIGIENSIS

Bomarea ×cantabrigiensis Chitt. is a seldom grown, twining hybrid which was raised at Cambridge University Botanic Garden. The origin of the hybrid is discussed along with the taxonomic history of the genus and the parents.     

A new nothogenus and nothospecies in the Oncidiinae (Orchidaceae) from Quintana Roo,Mexico

We propose the new nothogenus, ×Cohnlophiaris Cetzal & Balam (Cohniella×Lophiaris) based on a natural intergeneric hybrid, ×Cohnlophiaris quintanarooensis Cetzal & Carnevali (Cohniella ascendens×Lophiaris oerstedii) from a locality in Quintana Roo, Mexico, which is here described and illustrated. The new nothospecies is vegetatively similar to C. ascendens but the flowers show intermediate characters between the putative parents. ×Cohnlophiaris quintanarooensis is similar to C. ascendens by having yellow petals and sepals with brown or reddish spots, transversely subquadrate central lobe, central keel parallel to the proximal and distal teeth, and pollinarium of Cohniella type. On the other hand, is it similar to L. oerstedii in the papillose abaxial surface of petals and sepals, the oblong lateral lobes of the labellum, the subquadrate column base, the pentagonal cavity stigmatic and the pink clinandrium. A key to diagnose the new intergeneric hybrid and its putative parents, a comparative figure and a map showing their geographical distribution are provided.     

Isozyme evidence of the parental origin and possible fertility of the hybrid Potamogeton×fluitans Roth

 The hybrid Potamogeton×fluitans Roth is thought to have resulted from hybridization between P. lucens L. and P. natans L. This hybrid has only been recorded at a few locations in the British Isles. At most of these sites the number of individuals found have been quite low. The one exception to this being a population in the Moors River, Dorset and South Hampshire, England, where a substantially larger population exists. Using seven different enzyme systems, this study provided support for the putative parental origin of this hybrid. In addition, the population in the Moors River was shown to contain numerous multi-locus phenotypes suggesting that these individuals may be partially fertile and may backcross to one of its parental species, or alternatively undergo selfing or crossing to produce an F₂ generation. Received December 1, 2000 Accepted June 20, 2001     

Two new spontaneous hybrids of American hard pines from Pinus sect. Trifoliae (Pinaceae) found in the unique Russian Sochi Arboretum

In the 1990s, an extraordinarily abundant live collection of the genus Pinus, including 49 species, 4 subspecies, and 7 interspecific hybrids, found in the Sochi Arboretum in Russia on the northeast coast of the Black Sea, was taxonomically revised. Among these taxa, two previously unknown interspecific hybrids of American hard pine species from P. sect. Trifoliae had arisen spontaneously in culture. These are described here as the new hybrid species Pinus × transamericana (P. muricata × P. rigida) and Pinus × critchfieldii (P. patula × P. taeda). All known natural or artificial interspecific hybrids within P. sect. Trifoliae are listed, and hybridization between American hard pine species is discussed. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Dietary phosphorus affected growth performance,body composition,antioxidant status and total P discharge of young hybrid sturgeon (♀Huso huso × ♂Acipenser schrenckii) in winter months

An 8‐week feeding trial was carried out using young hybrid sturgeon (♀Huso huso × ♂Acipenser schrenckii) to study the effects of dietary phosphorus (P) on growth performance, body composition, liver and serum antioxidant status as well as the effluent P content in the wintertime. Four puffed pellet diets were formulated to contain graded total P levels at 0.63, 1.15, 1.85, and 2.12%, respectively. Triplicate groups of hybrid sturgeon (494.21 ± 18.63 g) were reared in concrete ponds (2.0 × 1.2 × 1.4 m), and fed one of the four diets for 8 weeks. Weight gain and feeding rate significantly decreased with increasing dietary P content, and fish fed the 2.12% P diet had negative growth. With the increase in dietary P, whole body ash and P content significantly increased. There was no inverse relationship between the whole body lipid content and dietary P level in young hybrid sturgeon. Hybrid sturgeon liver exhibited higher superoxide dismutase, catalase and glutathione peroxidase activities in the 0.63 and 1.15% dietary P treatment groups than those in the other two groups. Serum alkaline phosphatase activity increased significantly with increasing dietary P. Discharge of P into the pond increased significantly with increasing dietary P. In conclusion, a dietary P content between 0.63 and 1.15% helped young hybrid sturgeon to activate their antioxidant defense system and eradicate the free radicals, in order to reduce the antioxidant damage, while still keeping total P content in the pond at a relatively low level during the winter months.     

Production of intergeneric hybrid between dwarfing polish wheat (<Emphasis Type="Italic">Triticum polonicum</Emphasis> L.) and <Emphasis Type="Italic">Aegilops tauschii</Emphasis> Cosson. with reference to wheat origin

Dwarfing polish wheat is a dwarfing accession of Triticum polonicum L. from Xinjiang of China. In the present study, the artificial hybridization between dwarfing polish wheat and two accessions of Aegilops tauschii Cosson. (AS60 and AS65) was carried out, and the F₁ hybrids were obtained successfully without using embryo rescue techniques for the first time. The crossabilities of hybrids T. polonicum × Ae. tauschii (AS60) and T. polonicum × Ae. tauschii (AS65) were 1.67% and 0.60% respectively. Only the hybrids of T. polonicum × Ae. tauschii (AS60) germinated well, and 24 F₁ hybrid plants were obtained. All the F₁ hybrid plants grew vigorously, and the morphological traits were similar to bread wheat. The F₁ plants had some obvious traits inherited from T. polonicum and Ae. tauschii and were completely sterile. Chromosome pairing in the hybrid was characterized by a large number of univalents, with an average of 20.56 and 0.22 bivalents per PMC, and no ring bivalents and multivalents were observed. Furthermore, the potential value of the F1 hybrids between T. polonicum and Ae. tauschii for studying wheat origin and breeding are discussed. The article is published in the original.