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Panama disease of banana, caused by the fungus Fusarium oxysporum f. sp. cubense, is a serious constraint both to the commercial production of banana and cultivation for subsistence agriculture. Previous work has indicated that F. oxysporum f. sp. cubense consists of several clonal lineages that may be genetically distant. In this study we tested whether lineages of the Panama disease pathogen have a monophyletic origin by comparing DNA sequences of nuclear and mitochondrial genes. DNA sequences were obtained for translation elongation factor 1 alpha and the mitochondrial small subunit ribosomal RNA genes for F. oxysporum strains from banana, pathogenic strains from other hosts and putatively nonpathogenic isolates of F. oxysporum. Cladograms for the two genes were highly concordant and a partition-homogeneity test indicated the two datasets could be combined. The tree inferred from the combined dataset resolved five lineages corresponding to \"F. oxysporum f. sp. cubense\" with a large dichotomy between two taxa represented by strains most commonly isolated from bananas with Panama disease. The results also demonstrate that the latter two taxa have significantly different chromosome numbers. F. oxysporum isolates collected as nonpathogenic or pathogenic to other hosts that have very similar or identical elongation factor 1 alpha and mitochondrial small subunit genotypes as banana pathogens were shown to cause little or no disease on banana. Taken together, these results indicate Panama disease of banana is caused by fungi with independent evolutionary origins

We used nuclear ribosomal DNA internal transcribed spacer region (ITS 1 - 5.8S - ITS 2; ITS) sequences to generate the first phylogeny of Rubus based on a large, molecular data set. We sampled 57 taxa including 20 species of subgenus Rubus (blackberries), one to seven species from each of the remaining 11 subgenera, and the monotypic and closely related Dalibarda. In Rubus, ITS sequences are most informative among subgenera, and variability is low between closely related species. Parsimony analysis indicates that Rubus plus Dalibarda form a strongly supported clade, and D. repens may nest within Rubus. Of the subgenera with more than one species sampled, only subgenus Orobatus appears monophyletic. Three large clades are strongly supported: one contains all sampled species of nine of the 12 subgenera; another includes extreme Southern Hemisphere species of subgenera Comaropsis, Dalibarda, and Lampobatus; and a third clade consists of subgenus Rubus plus R. alpinus of subgenus Lampobatus. Rubus ursinus appears to be a hybrid between a close relative of R. macraei (subgenus Idaeobatus, raspberries) and an unidentified subgenus Rubus species. ITS sequences are generally consistent with biogeography and ploidy, but traditionally important morphological characters, such as stem armature and leaf type, appear to have limited phylogenetic value in Rubus.

An investigation was conducted on the number and morphology of the chromosomes of four species from the family Commelinaceae: Spironema fragrans Lindl., Setcreasea purpurea Boom, Tradescantia albiflora Kunth. and Tradescantia blossfeldiana Mildbr.

Introduction. Chinese jujube originated in China and has become a leading fruit tree in the northern part of China with total production of 4,250,000 t in 2009 and total planting area of 1,500,000 ha. Among the reported 944 Chinese jujube cultivars or strains, ‘Zanhuangdazao’ is the unique natural triploid cultivar; it is characterized by big fruit, high yield and good adaptability compared with the other diploid cultivars. Therefore, our group began polyploid breeding through colchicine induction starting in 2000. Cultivar origin. ‘Chenguang’ is a new Chinese jujube cultivar induced by colchicine on the stem apex of the diploid ‘Linyilizao’. Through three years of top-grafting and purification, its characteristics were observed in grafted and top-grafted experimental orchards continually. In 2009, ‘Chenguang’ was released by the Hebei Forestry Cultivar Examination and Approval Committee and became the unique tetraploid Chinese jujube cultivar in the world to date. Cultivar characteristics. The somatic chromosome number, botanical character, phenological phase, productivity and adaptability are given. ‘Chenguang’ is suitable for growing in Shanxi, Hebei, Shandong Province, where the annual average temperature is 12–14 °C and rainfall is above 400 mm, or similar soil and climate conditions. Main cultural techniques. Propagation, the training system, fruit setting and disease control are explained and recommended. Introduction. Le jujubier chinois est originaire de Chine ; il est devenu un arbre fruitier de premier plan dans le nord de la Chine avec une production totale de 4.250.000 t en 2009 pour une superficie totale de plantation de 1.500.000 ha. Parmi les 944 cultivars ou souches de jujubiers chinois signalés, « Zanhuangdazao » est l'unique cultivar triploïde naturel ; il est caractérisé par de gros fruits, un rendement élevé et une bonne adaptabilité comparé aux cultivars diploïdes. Notre groupe a donc entrepris la sélection de polyploïdes de jujubier par induction à la colchicine à partir de l’an 2000. Origine du cultivar. « Chenguang » est un nouveau cultivar de jujubier chinois induit par colchicine sur apex de la tige du diploïde « Linyilizao ». Après trois ans de surgreffage et de purification, ses caractéristiques ont été observées en vergers expérimentaux continuellement greffés et surgreffés. En 2009, le cultivar « Chenguang » a été mis sur le marché par le comité de validation et de caractérisation des cultivars de sylviculture de Hebei et il est à ce jour l'unique cultivar tétraploïde de jujubier chinois de par le monde. Caractéristiques du cultivar. Le nombre de chromosomes somatiques, les caractères botaniques, la phase phénologique, la productivité, l'adaptabilité ont été étudiés. Le cultivar «Chenguang» est adapté à la culture dans le Shanxi, du Hebei, province de Shandong (Chine), où la température moyenne annuelle est de 12–14 °C et les précipitations sont supérieures à 400 mm, ou dans toutes autres régions présentant des conditions pédologiques et climatiques analogues. Principales techniques culturales. La propagation, la taille de formation, la mise à fruit, et le contrôle des maladies ont été décrits et des recommandations sont données. Introducción. El azufaifo chino es originario de China. Se ha convertido en un frutal de primer orden en el norte de China con una producción total de 4.250.000 t en 2009 para una superficie de plantación total de 1.500.000 ha. Entre los 944 cultivares o tocones de azufaifos chinos señalados, « Zanhuangdazao » es el único cultivar triploide natural. Se le caracteriza por sus grandes frutos, un elevado rendimiento y una buena adaptabilidad, en comparación con los cultivares diploidos. Nuestro grupo se dispuso por lo tanto a seleccionar poliploides de azufaifo por inducción con colchicina a partir de 2000. Origen del cultivar. « Chenguang » es un nuevo cultivar de azufaifo chino inducido por colchicina en la yema apical del diploido « Linyilizao ». Después de tres años de sobreinjerto y de purificación, se observaron sus características en vergeles experimentales continuamente injertados y sobreinjertados. En 2009, el cultivar « Chenguang » se lanzó al mercado por el comité de validación y de caracterización de los cultivares de silvicultura de Hebei y, a día de hoy, es el único cultivar tetraploide de azufaifo chino a través del mundo. Características del cultivar. Se estudiaron el número de cromosomas somáticos, los caracteres botánicos, la fase fenológica, la productividad y la adaptabilidad. El cultivar « Chenguang » está adaptado al cultivo en el Shanxi, Hebei, provincia de Shandong (China), donde la temperatura media anual es de 12–14 °C y las precipitaciones son superiores a 400 mm, así como en cualquier otra región que presente semejantes condiciones edafológicas y climáticas. Principales métodos de cultivo. Se describieron la propagación, el tamaño de formación, la fructificación y el control de las enfermedades y se dieron igualmente recomendaciones.

The angiosperm family Rosaceae poses a number of noteworthy systematic problems as well as many questions concerning morphological and chromosomal evolution. Phylogenetic analysis of rbcL gene sequences was performed to address systematic and evolutionary problems of Rosaceae. Both rbcL sequence variation and the presence of duplicated sequences near the 3' end of rbcL were useful in determining phylogenetic relationships in this family. Analyses of rbcL sequences indicate that there are groups of genera within Rosaceae comparable to the subfamilies Maloideae, Amygdaloideae, and Rosoideae, although the composition of each group differs from traditional circumscriptions. According to analysis of rbcL data, Maloideae and Amygdaloideae each include additional taxa not normally associated with them. All members of Rosoideae with x = 9 are phylogenetically well separated from the x = 8 and 7 members of the subfamily. In addition, Spiraeoideae are not monophyletic but appear to consist of several distinct evolutionary lineages. The rbcL-based phylogenies suggest that chromosome numbers are more reliable indicators of some generic alliances than the more commonly used fruit types. Sequence data are also useful in determining the alliances of several problematic genera, suggesting that the capsular and follicular-fruited genera Vauquelinia, Lindleya, and Kageneckia (usually placed in Spiraeoideae) should be included in the pome-fruited subfamily Maloideae, and that Quillaja is not a member of Rosaceae. Molecular data are consistent with several suggestions for the ancestral chromosome numbers and fruit types of Rosaceae, but do not support any one hypothesis for either. This study also suggests that the subfamily Maloideae may have descended from spiraeoid ancestors and that the pome is derived from follicular or capsular fruit types

Plants are the basis of life on earth. We cannot overemphasize their importance. The value of plant genome initiatives is self-evident. The need is to identify priorities for action. The angiosperm genome is highly variable, but the extent of this variability is unknown. Uncertainties remain about the number of genes and the number of species living. Many plants will become extinct before they are discovered. We risk losing both genes and vital information about plant uses. There are also major gaps in our karyotypic knowledge. No chromosome count exists for 70% of angiosperm species. DNA C values are known for only approximately 1% of angiosperms, a sample unrepresentative of the global flora. Researchers reported new relationships between genome size and characters of major interest for plant breeding and the environment and the need for more data. In 1997, a Royal Botanic Gardens Kew workshop identified gaps and planned international collaboration to fill them. An electronic version of the Angiosperm DNA C value database also was published. Another initiative, which will make a very significant contribution to the conservation of plant genetic diversity on a global scale is Kew's Millennium Seed Bank, partly funded by the U.K. Millennium Commission, celebrating the year 2000. Costing up to 80 million pounds (1 million pounds = $1.62), its main aims are to collect and conserve the seed of almost all of the U.K. spermatophyte flora by the year 2000, to collect and conserve a further 10% of the world spermatophyte flora principally from the drylands by 2009, and to provide a world class building as the focus of this activity by 2000

Rfp-Y is a second region in the genome of the chicken containing major histocompatibility complex (MHC) class I and II genes. Haplotypes of Rfp-Y assort independently from haplotypes of the B system, a region known to function as a MHC and to be located on chromosome 16 (a microchromosome) with the single nucleolar organizer region (NOR) in the chicken genome. Linkage mapping with reference populations failed to reveal the location of Rfp-Y, leaving Rfp-Y unlinked in a map containing 400 markers. A possible location of Rfp-Y became apparent in studies of chickens trisomic for chromosome 16 when it was noted that the intensity of restriction fragments associated with Rfp-Y increased with increasing copy number of chromosome 16. Further evidence that Rfp-Y might be located on chromosome 16 was obtained when individuals trisomic for chromosome 16 were found to transmit three Rfp-Y haplotypes. Finally, mapping of cosmic cluster III of the molecular map of chicken MHC genes (containing a MHC class II gene and two rRNA genes) to Rfp-Y validated the assignment of Rfp-Y to the MHC/NOR microchromosome. A genetic map can now be drawn for a portion of chicken chromosome 16 with Rfp-Y, encompassing two MHC class I and three MHC class II genes, separated from the B system by a region containing the NOR and exhibiting highly frequent recombination

The genus Paullinia includes the economically important P. cupana, known as guarana in Brazil and more recently in the world market. Native Americans of the Maue and Andira tribes cultivated P. cupana 'Sorbilis' in central Amazon, and the Bares cultivated the 'Typica' variety in the upper Negro River (Brazil). Cytological studies in the Sapindaceae family have concentrated on the diversity in number (from 2n = 14 to 96) and size of the chromosomes. In Paullinia, seven species have been karyotyped and all show 2n = 24. Meristem maceration, cellular dissociation and air-drying techniques were used for cytogenetic preparations and DNA content was determined by flow cytometry. Chromosome characterization and DNA content of Paullinia cupana Kunth 'Sorbilis' (Mart.) Ducke (Sapindaceae) were studied. The high chromosome number (2n = 210) fall into two cytomorphological groups: (a) a metacentric and submetacentric group showing 25 sets of three pairs of chromosomes (2-76); (b) a group containing only acrocentric showing 12 sets of two pairs of chromosomes (82-105), a homologous submetacentric pair (1) and an acrocentric pair (81). Mean nuclear DNA content of guarana was 2C = 22.8 pg. A karyogram was set up showing a high chromosome number complement.

The multiple independent origins of eusociality in the insect order Hymenoptera are clustered in only four of more than 80 families, and those four families are two pairs of closely related taxa in a single part of the order. Therefore, although ordinal-level characteristics can contribute to hymenopteran eusocial evolution, more important roles have been played by traits of infraordinal taxa that contain the eusocial forms. Many factors have been proposed and discussed, but assessments of traits' salience to eusocial evolution have heretofore not been joined to phylogenetics. In the present analysis, cladograms of superfamilies and families of Hymenoptera and of the family Vespidae are used to ordinate the appearance of traits that play roles in vespid eusociality. Proximity of traits' first appearance to the origin of eusocial Vespidae is taken as one measure of traits' salience to vespid eusocial evolution. Traits that subtend only eusocial taxa and that are uniquely associated with eusociality have foundations in more general traits that subtend more inclusive taxa. No single trait is uniquely causative of vespid eusocial evolution. High-salience traits that closely subtend vespid eusociality include nesting, oviposition into an empty nest cell, progressive provisioning of larvae, adult nourishment during larval provision malaxation, and inequitable food distribution among nestmates. The threshold characteristic of Polistes-grade eusociality is life-long alloparental brood care by first female offspring who remain, uninseminated, at their natal nest. Traits directly associated with occurrence of such workers are larva-adult trophallaxis, which can foster relatively low larval nourishment early in a colony cycle, and protogyny and direct larval development, which combine to yield restricted mating opportunities for female offspring that are the first to emerge in the colony cycle. Trait mapping suggests no role for asymmetry of relatedness due to haplodiploidy, but it suggests high salience for haplodiploidy as a mechanism enabling the production of all-female clutches of first offspring.