A Biosystematic Study of Microseris Subgenus Monermos (Compositae: Cichorieae)

<p>The taxonomy of Microseris subgenus Monermos (Hook. f.) Chambers (Compositae) is investigated. Two species are recognized, namely M. scapigera (sol. ex A. Cunn.) Sch.-Bip. and M. lanceolata (Walp.) Sch.-Bip., which are confined to New Zealand and Australia respectively. In M. scapigera, taxonomic subdivision was not practicable, the formae of Allan (1961) not being upheld. Microseris lanceolata is subdivided into three groups which are described informally as races. The races are viewed as probable subspecies but need further study before this status can be confirmed. The two species are described and illustrated and details are given for each on typification, synonymy, chromosome number, distribution, ecology and geographical variation. Strong self-incompatibility is prevalent in both M. scapigera and M. lanceolata. The only exceptions in the populations examined were in M. scapigera, in which two populations were only moderately self incompatible, and another was substantially self-compatible. The last population appeared to have morphological and behavioural adaptations to promote autogamy. Artificial hybridizations were made within and between the two species. Microseris scapigera and M. lanceolata were freely or poorly intercrossable according to the populations used, and formed semi-fertile or sterile hybrids. Semi-fertile hybrids were virtually blocked from forming a F2 generation (fruit set was very low and no fruits germinated) but they cold be backcrossed. Fertility in BC1 hybrids was mostly higher than in the F1, but was not restored to normal. Microseris scapigera and M. lanceolata race 1 appear to have largely homologous chromosomes. Attempts to cross the species of subgenus Monermos with M. borealis (subgenus Apargidium) were unsuccessful</p>

A Biosystematic Study of Microseris Subgenus Monermos (Compositae: Cichorieae)

<p>The taxonomy of Microseris subgenus Monermos (Hook. f.) Chambers (Compositae) is investigated. Two species are recognized, namely M. scapigera (sol. ex A. Cunn.) Sch.-Bip. and M. lanceolata (Walp.) Sch.-Bip., which are confined to New Zealand and Australia respectively. In M. scapigera, taxonomic subdivision was not practicable, the formae of Allan (1961) not being upheld. Microseris lanceolata is subdivided into three groups which are described informally as races. The races are viewed as probable subspecies but need further study before this status can be confirmed. The two species are described and illustrated and details are given for each on typification, synonymy, chromosome number, distribution, ecology and geographical variation. Strong self-incompatibility is prevalent in both M. scapigera and M. lanceolata. The only exceptions in the populations examined were in M. scapigera, in which two populations were only moderately self incompatible, and another was substantially self-compatible. The last population appeared to have morphological and behavioural adaptations to promote autogamy. Artificial hybridizations were made within and between the two species. Microseris scapigera and M. lanceolata were freely or poorly intercrossable according to the populations used, and formed semi-fertile or sterile hybrids. Semi-fertile hybrids were virtually blocked from forming a F2 generation (fruit set was very low and no fruits germinated) but they cold be backcrossed. Fertility in BC1 hybrids was mostly higher than in the F1, but was not restored to normal. Microseris scapigera and M. lanceolata race 1 appear to have largely homologous chromosomes. Attempts to cross the species of subgenus Monermos with M. borealis (subgenus Apargidium) were unsuccessful</p>

The Biology of Canadian Weeds. xxx. Capsella bursa-pastoris (L.) Medik.

<i>Capsella bursa-pastoris</i> (L.) Medik, shepherd’s purse, is a cosmopolitan summer or winter annual weed species distributed throughout temperate and subtropical regions of the world and is considered one of the most common plants on earth. It is an opportunistic annual that colonizes newly disturbed, open or dry environments and is ubiquitous in cultivated lands in Canada. In annual crops in western Canada, <i>C. bursa-pastoris</i> has been among the 20 most abundant weeds since the first weed surveys in 1970. It is most easily distinguished by its small white four-petalled flowers and its heart-shaped seed-pods, but exhibits considerable variation in leaf shape and flowering time. It has been used for food and medicine by numerous cultures. Its golden-brown seeds are produced in large numbers predominantly through self-pollination and can form a substantial seed bank, with reported values ranging to several hundred thousand seeds m^-2. While seeds usually disperse near the mother plant, long-distance dispersal by attaching to vehicles, people and other vectors may be facilitated by its mucilaginous coat. <i>Capsella bursa-pastoris</i> does not produce fertile hybrids with other species of economic or ecological significance. It is generally well controlled by soil-applied and foliar (post-emergence) herbicides although its presence in agricultural fields may result in substantial yield loss, as documented in cole crops in North America and grain crops in Europe. The species can host a wide range of insect, nematode, fungal, viral, and bacterial pests that may damage crop species.

PSVIII-2 Genetic diversity analysis of hybrid Karachaev goats (Capra hircus) population using microsatellite marker data

The Karachaev goat is an indigenous breed that possesses unique features including significantly less fat deposition in the body compared to sheep and cattle, ability to graze at an altitude of up to 1200 meters and to produce fertile hybrids with wild relatives. To understand the genetic diversity and population structure of hybrids between domestic Karachaev goats (Capra hircus) and The West Caucasian tur (Capra caucasica) 143 individuals were analyzed using 10 microsatellites panel. Sample were analyzed according to the manufacturer’s recommendations on an automatic sequencer, ABI 3130XL genetic analyzer (Applied Biosystems). Genetic diversity was calculated using GenAlEx 6.503 software. Genotyping of ten microsatellite loci in hybrid forms of Karachaev goats and turs detected 106 alleles in total. Na values ranged from five (INR063) to seventeen (SRCRSO008), averaging 10.6 alleles per locus across the 10 loci. All loci were polymorphic. The average number of alleles was 10.6 alleles per locus. This is higher than the similar indicator obtained by Kharzinova et al. (2019) in populations of Soviet wool, Tajik wool, Orenburg downy, Alpine and Zaanen dairy breeds of goats, studied using the panel of same 10 STR-markers (9.3 loci). Other key indexes of genetic diversity could be found in table 1. The values of the coefficient FIS suggest the absence of related mating in the herd. Information on genotypic variability of Karachaev goats hybrid forms obtained here will contribute into the breeding programs improvement and to preservation of existing native breeds.

Are There Any Traces of Pinus uliginosa in the Stołowe Mountains Outside the Wielkie Torfowisko Batorowskie and Błędne Skały?

Pinus sylvestris (Scots pine) and taxa from the P. mugo (mountain pine) complex hybridize in contact zones producing morphologically-intermediate fertile hybrids. However, the hybrid specimens sometimes express only the P. sylvestris phenotype. Such cryptic hybrids were detected among P. sylvestris and P. uliginosa in the western part of Błędne Skały in the Stołowe Mountains, where the pines grow on the tops of sandstone rocks and phenotypically resemble P. sylvestris , P. uliginosa , and P. mugo . Hybrids with the P. sylvestris phenotype could be potentially present in other relic populations of this species in these mountains. During the present study, the hybrids were identified only in the area of Błędne Skały based on chloroplast and mitochondrial markers, morphological differentiation of various needle and cone traits, and phenotype assessments of the trees during sampling. These hybrids included three cryptic hybrids of P. sylvestris × P. mugo with the P. sylvestris phenotype and one displaying the phenotype of P. uliginosa . The other populations analyzed represented Scots pine with no evidence of hybridization with P. uliginosa and/or P. mugo . Biometric data on the cone and needle morphology also suggest possible hybridization within the P. mugo complex on Błędne Skały. The results indicate that hybridization takes place in this population but not in neighboring populations despite the possible connection by pollen-mediated gene flow.

“An Inexplicable Confusion”

While visiting Galápagos, the young Charles Darwin was confused by the similarity of various finches he observed. We now understand that what we see as different finch species are “species before speciation is complete.” The confusion is inherent: many of them remain similar enough to form fertile hybrids. But a robust difference exists between the groups of ground finches and tree finches, raising the question, what prompted the evolution of that clear distinction? The primary habitats for tree finches are tree species of the wonderful Galápagos daisy genus, Scalesia, that dominate the forests of the humid areas of various islands. Did the evolution of daisies into trees influence the evolution of differences between ground and tree finches? For that matter, how did highland trees evolve from lowland shrubby daisies, thus forming the highland habitat for tree finches? Several lines of evidence, including a contemporary interaction analysis of various birds and trees, suggest that the giant daisies of Galápagos and the tree species of Darwin’s finches coevolved.

Interspecific hybrids of Juglans regia L.

Persian walnut (Juglans regia L.) is an important tree primarily for its nutritious nuts and high-quality wood. Based on the analysis of literature sources, it was found that hybridization played a significant role in the evolution of the genus Juglans. Persian walnut can interbreed with many walnut species with the formation of fertile hybrids. There are two-species, three-species, and four-species hybrids in different combinations of crossings. They are used in forestry as a source of wood, in horticulture as rootstocks, and in breeding for more durable resistance against pathogens and tolerance against abiotic stresses. Some interspecific hybrids have validly published scientific names, but many of the proposed names do not meet the rules of the International Nomenclature Code for algae, fungi, and plants.

Reproductive Output and Insect Behavior in Hybrids and Apomicts from Limonium ovalifolium and L. binervosum Complexes (Plumbaginaceae) in an Open Cross-Pollination Experiment

Ex situ plant collections established from seeds of natural populations are key tools for understanding mating systems of intricate taxonomic complexes, as in the Limonium Mill. genus (sea lavenders, Plumbaginaceae). Plants show a polymorphic sexual system associated to flower polymorphisms such as ancillary pollen and stigma and/or heterostyly that prevents self and intramorph mating. The main objectives of this study were to investigate the significance of pollen-stigma dimorphisms and the role of flower visitors in the reproductive output of hybrids arising from sexual diploids of Limonium ovalifolium complex and apomicts tetraploids of L. binervosum complex in an open cross-pollination experiment. Results showed that, similarly to parental plants, hybrids present inflorescence types, self-incompatible flowers, and produced regular pollen grains with the typical exine patterns, with medium to high viability. By contrast, apomicts show floral polymorphisms, inflorescences, and pollen grains of maternal phenotype but with low stainability. Several insects’ species visited the inflorescences of parental plants and both hybrids and apomicts and some of these insects carried A and/or B pollen grains on their bodies, especially Clepsis coriacana (Rebel) and Tapinoma sp. Insects’ floral visits to hybrids and apomicts seem to be independent of pollen fertility and plants’ reproductive modes. Both hybrids and apomicts were able to produce fertile seeds, although the latter showed more seedlings with developmental anomalies than the first plants. The findings demonstrate that there is a weak reproductive barrier between the diploid species of L. ovalifolium complex as they can hybridize and produce fertile hybrids, provided there is pollen transport by pollinator insects. This study supports that apomixis is a strong reproductive barrier between both L. ovalifolium and L. binervosum complexes but did not allow us to exclude reproductive interferences of apomict pollen into sexuals.

Distribution and hybridization of two sedentary gobies (Pomatoschistus microps and Pomatoschistus marmoratus) in the lagoons of southern France

Pomatoschistus marmoratus and Pomatoschistus microps are small sedentary gobies inhabiting the lagoons of European Mediterranean and Atlantic coasts. Along the French Mediterranean coast their respective geographical distribution is not precisely known, in part because they are cryptic species. In this study, 512 gobies of both species were caught as 17 samples in 12 lagoons of the Gulf of Lion on the French Mediterranean coast. They were genotyped at six microsatellite loci and investigated statistically using multidimensional analyses, Bayesian assignment (Structure) and NewHybrids classification. This allowed the contrasted distribution of each species (P. microps in the east, P. marmoratus in the west) to be described, with several exceptions. Neither geographic structure nor isolation by distance was detected among differentiated populations of each species. The suggested mechanism is a deep sedentary behaviour associated with foundations following extinctions. The two species are sympatric or even in syntopy in five or six sampled lagoons producing rare fertile hybrids.

Genetic Consequences of Hybridization in Relict Isolated Trees Pinus sylvestris and the Pinus mugo Complex

Scots pine (Pinus sylvestris L.) and the taxa from the P. mugo complex can hybridize in the contact zones and produce fertile hybrids. A unique example of an early Holocene relict population of P. sylvestris and P. uliginosa (a taxon from the P. mugo complex) growing on the tops of Jurassic sandstone rocks is located in Błędne Skały (Sudetes). Phenotypically, there are trees resembling P. sylvestris, P. uliginosa and intermediate forms between them. We expected that some of P. sylvestris and/or P. uliginosa-like trees could be in fact cryptic hybrids resembling one of the parental phenotypes. To address this question, we examined randomly sampled individuals, using a set of plastid (cpDNA), nuclear (nDNA) and mitochondrial (mtDNA) markers as well as biometric characteristics of needles and cones. The results were compared to the same measurements of allopatric reference populations of the P. sylvestris and the P. mugo complex (Pinus mugo s.s, P. uncinata and P. uliginosa). We detected cpDNA barcodes of the P. mugo complex in most individuals with the P. sylvestris phenotype, while we did not detect cpDNA diagnostic of P. sylvestris within P. uliginosa-like trees. These results indicate the presence of cryptic hybrids of the P. sylvestris phenotype. We found only three typical P. sylvestris individuals that were clustered with the species reference populations based on needle and cone characteristics. Most trees showed intermediate characteristics between P. sylvestris and P. uliginosa-like trees, indicating intensive and probably long-lasting hybridization of the taxa at this area and subsequent gene erosion of parental species.