Cytogenetic evidence supports Avena insularis being closely related to hexaploid oats.

Cytogenetic observations, phylogenetic studies and genome analysis using high-density genetic markers have suggested a tetraploid Avena species carrying the C and D genomes (formerly C and A) to be the donor of all hexaploid oats (AACCDD). However, controversy surrounds which of the three extant CCDD tetraploid species - A. insularis , A. maroccana and A. murphyi - is most closely related to hexaploid oats. The present work describes a comparative karyotype analysis of these three CCDD tetraploid species and two hexaploid species, A. sativa and A. byzantina . This involved the use of FISH with six simple sequence repeats (SSRs) with the motifs CT, AAC, AAG, ACG, ATC and ACT, two repeated ribosomal sequences, and C genome-specific repetitive DNA. The hybridization pattern of A. insularis with oligonucleotide (AC) 10 was also determined and compared with those previously published for A. sativa and A. byzantina . Significant differences in the 5S sites and SSR hybridization patterns of A. murphyi compared to the other CCDD species rule out its being directly involved in the origin of the hexaploids. In contrast, the repetitive and SSR hybridization patterns shown by the D genome chromosomes, and by most of the C genome chromosomes of A. maroccana and A. insularis , can be equated with the corresponding chromosomes of the hexaploids. Several chromosome hybridization signals seen for A. insularis , but not for A. maroccana , were shared with the hexaploid oats species, especially with A. byzantina . These diagnostic signals add weight to the idea that the extant A. insularis , or a direct ancestor of it, is the most closely related progenitor of hexaploid oats. The similarity of the chromosome hybridization patterns of the hexaploids and CCDD tetraploids was taken as being indicative of homology. A common chromosome nomenclature for CCDD species based on that of the hexaploid species is proposed.

Automatic morphology phenotyping of tetra- and hexaploid wheat spike using computer vision methods

Intraspecific classification of cultivated plants is necessary for the conservation of biological diversity, study of their origin and their phylogeny. The modern cultivated wheat species originated from three wild diploid ancestors as a result of several rounds of genome doubling and are represented by di-, tetra- and hexaploid species. The identification of wheat ploidy level is one of the main stages of their taxonomy. Such classification is possible based on visual analysis of the wheat spike traits. The aim of this study is to investigate the morphological characteristics of spikes for hexa- and tetraploid wheat species based on the method of high-performance phenotyping. Phenotyping of the quantitative characteristics of the spike of 17 wheat species (595 plants, 3348 images), including eight tetraploids (Triticum aethiopicum, T. dicoccoides, T. dicoccum, T. durum, T. militinae, T. polonicum, T. timopheevii, and T. turgidum) and nine hexaploids (T. compactum, T. aestivum, i:ANK-23 (near-isogenic line of T. aestivum cv. Novosibirskaya 67), T. antiquorum, T. spelta (including cv. Rother Sommer Kolben), T. petropavlovskyi, T. yunnanense, T. macha, T. sphaerococcum, and T. vavilovii), was performed. Wheat spike morphology was described on the basis of nine quantitative traits including shape, size and awns area of the spike. The traits were obtained as a result of image analysis using the WERecognizer program. A cluster analysis of plants according to the characteristics of the spike shape and comparison of their distributions in tetraploid and hexaploid species showed a higher variability of traits in hexaploid species compared to tetraploid ones. At the same time, the species themselves form two clusters in the visual characteristics of the spike. One type is predominantly hexaploid species (with the exception of one tetraploid, T. dicoccoides). The other group includes tetraploid ones (with the exception of three hexaploid ones, T. compactum, T. antiquorum, T. sphaerococcum, and i:ANK-23). Thus, it has been shown that the morphological characteristics of spikes for hexaploid and tetraploid wheat species, obtained on the basis of computer analysis of images, include differences, which are further used to develop methods for plant classifications by ploidy level and their species in an automatic mode.

Chrysanthemum ×hybridum MN 98-89-7 Shrub Garden Chrysanthemum

A new garden chrysanthemum with a shrub plant habit is released as a descendent of a cross involving two hexaploid species: Chrysanthemum weyrichii (Maxim.) Tzvelv. (female) × C. ×grandiflorum Tzvelv. (male). Chrysanthemum ×hybridum Anderson MN 98-89-7 [U.S. Plant Patent (PP) 14,495] is a vigorously growing shrub chrysanthemum for garden culture, exhibiting extreme hybrid vigor. Single daisy reddish-purple flowers cover the foliage in the fall, numbering >3000 on second-year plants. This selection displays excellent winterhardiness in U.S. Department of Agriculture (USDA) Z3b+ (–34.4 to –37.2 °C) as well as frost-tolerant flowers. In its second and subsequent years of growth after planting, MN 98-89-7 grows into a fall flowering (August–October), herbaceous shrub ranging in plant height from 61.0 to 91.4 cm with a diameter of 76.2 to 152.4 cm. Its spherical plant shape is achieved naturally with self-pinching, creating a highly manicured appearance; it also attracts honey bees and butterflies as pollinators. MN 98-89-7 is a vegetative product and this unnamed selection is being released for germplasm purposes as well as for potential licensing and naming.

Molecular cloning of HMW glutenin subunits from Roegneria kamoji (Poaceae: Triticeae)

In the present study, The hexaploid species

Genetic diversity of seed storage proteins in diploid, tetraploid and hexaploid Avena species

Genetic diversities of 106 Avena accessions, including diploid, tetraploid and hexaploid species, derived from different countries were characterized based on seed storage proteins polymorphism using SDS-PAGE. A total of 24 protein bands and 72 protein patterns were detected in all 106 accessions. The genetic similarity value varied from 0.50 to 1.00. The seed storage protein patterns were largely independent of environmental fluctuation. Accessions of the same species or with identical genome constitutions had the same or similar protein patterns. Relatively lower within-species variations were observed compared with among-species variations. The AACCDD genome hexaploid species and the AA genome diploid species were more divergent than other species, with percentages of polymorphic bands of 85.7% and 61.1% respectively. In the AA genome diploid species, the AsAs genome diploids displayed higher variations than the modified AA genome diploid species. Clustering results showed a close relationship between the hexaploid species and the AACC genome tetraploid species. The AABB genome tetraploid species were similar to the AsAs genome diploid species, with the exception of the species A. agadiriana with AABB genome constitution, which showed a close relationship with the AcAc genome diploid species A. canariensis and the polyploid species carrying the A and C genomes.

The Importance of Polyploidy in Meconopsis with Particular Reference to the Big Perennial Blue Poppies

A comparison is made between evolution of the genus Meconopsis through natural selection, which takes a long time, and rapid evolution through polyploidy. The possible formation of the tetraploid Meconopsis grandis from the diploid M. baileyiis considered in detail. The possibility of an extended diploid to hexaploid chromosome series in the ‘Big Blue Poppies’ is discussed. Each component of the series is described. The formation of Meconopsis 'Linghol' as an example of a probable new hexaploid species with its evolution through somatic chromosome doubling is considered in detail. The possibiliity of pentaploids, a new ploidy level or cytotype in the proposed series, is discussed with putative examples. A glossary of terms used is provided.