Chromosome Number Of Plants Research Articles

Intergeneric hybridization of Diplotaxis erucoides with Brassica napus. I. cytogenetic analysis of F1 and BC1 progeny

Intergeneric hybrids (F1) Diplotaxis erucoides (DeDe) x Brassica napus (AACC) and the first backcross to B. napus (BC1) have been obtained through in vitro culture of excised ovaries. The chromosome numbers of F1 and BC1 plants proved the occurrence of unreduced gametes. The study of metaphase I chromosome pairing showed that autosyndesis in De genome and allosyndesis between De and A/C genomes might exist. The male fertility of the F1 plants was low. Some male-sterile plants were found in F1 and BC1 progeny. The possibilities of creating addition lines B. napus-D. erucoides and of obtaining a new cytoplasmic male sterility in B. napus are discussed.

Resynthesis of Brassies napus L. through Interspecific Hybridization between B. alboglabra Bailey and B. campestris L. with Special Emphasis on Seed Colour

Abstract Brassica napus L. was resynthesized through interspecific hybridization between B. alboglabra Bailey and B campestris L. with the objective or developing yellow‐seeded forms of this species. For hybridization, one black‐seeded form and one light brown‐seeded form of B. alboglabra (a subordinate of B. oleracea) and one brown and ten yellow‐seeded forms of B. campestris were chosen as parents. Crosses with B. alboglabra as the female parent were more successful than crushes with B. campestris as female. The use of the embryo rescue culture technique greatly increased the number of surviving hybrid embryos. Colchicine treatment was required for doubling the chromosome number of the amphihaploid hybrid plants. In the newly‐resynthesized rape forms, the white petal of B. alboglabra was partially epistatic over the yellow petal of B. campestris. The self compatibility of B. alboglabra was hypostatic to the self incompatibility of B. campestris. The black‐seeded character of B. alboglabra and the brown‐seeded character of B. campestris were completely eptstatic over the yellow‐seeded character of B. campestris and the light brown‐seeded character of B. alboglabra. Implications of the results from this study in breeding yellow‐seeded B. napus are discussed.

Chromosome Numbers of Madagascar Plants

Chromosome numbers are reported for 19 species in eight families of flowering plants of Madagascar. Included are first reports for 14 species. First counts for the genera Kaliphora (n = 16) and Haronga (n = 10) also are presented. A new low number (n = 7) is reported for the genus Vernonia, and the possible allopolyploid origin of New World taxa of the genus based on x = 17 is discussed. Although the flora of Madagascar contains many interesting and poorly known genera and families, chromosome counts are available for relatively few species. The present paper inaugurates what is intended to be a sustained effort to record the chromosome numbers of Madagascar plants so they will be available to assist in interpretation of phytogeographic and evolutionary relationships. MATERIALS AND METHODS With two exceptions, chromosome numbers reported here were determined from microsporocytes undergoing meiotic divisions. The two counts in the genus Aloe were made from microcytes undergoing the first mitotic division of microgametogenesis. All floral bud materials used for chromosomal determinations were preserved in a modified Carnoy's fixative (6 chloroform: 3 absolute ethanol: 1 glacial acetic acid). These were stored in the fixative under refrigeration until they were transported to the University of Hawaii where acetocarmine slide preparations were made according to a modification of Beeks' method (Beeks, 1955). Observations were made with a Zeiss Photoscope III equipped with phase contrast optics. Voucher specimens of all cytological determinations have been deposited in the Herbarium of the Service de Botanique, Universite de Madagascar, Tananarive (TAN).

Variation in Phenotype and Chromosome Number of Plants Regenerated from Protoplasts of Dihaploid and Tetraploid Potato

AbstractAn investigation was made on the origin and basis of somaclonal variation in potato. Plants were regenerated from protoplasts of dihaploid and tetraploid potato, and the degree of variation in phenotype and chromosome number was analysed. All the regenerants from dihaploid potato showed variation in chromosome number, while only part of these varied in plant morphology. In tetraploid potato, 60 % of the regenerants showed variation in chromosome number, all of which exhibited phenotypic changes. The data suggest that the explant source and the initial ploidy level of the genotype play an important role in influencing the degree of somaclonal variation.

Chromosome Numbers of New Caledonian Plants

Chromosome Numbers of New Caledonian Plants

Chromosome number and isoenzyme variation in Kentucky bluegrass cultivars and plants regenerated from tissue culture.

Chromosome number and isoenzyme variation in Kentucky bluegrass cultivars and plants regenerated from tissue culture.

From tumour to tuber; tumour cell characteristics and chromosome numbers of crown gall-derived tetraploid potato plants (Solanum tuberosum cv. ‘Maris Bard’)

Agrobacterium tumefaciens strains, known to induce tobacco crown galls that spontaneously develop shoots, were used to induce galls on cultured shoots of a tetraploid potato cultivar (Solanum tuberosum cv. 'Maris Bard'). Shoots also appeared spontaneously from the induced potato galls, although only after 2-4 months. The shoots were excised and cultured separately. Some of these frequently developed side-shoots from their axillary buds. They did not form roots and they produced opines, a strong indication that they were transformed and carried T-DNA. Grafts of the transformed plants were still able to develop tubers. Most of the tumour-derived shoots, however, formed roots, did not produce opines and were indistinguishable from the parental plants on the basis of morphology and chromosome numbers (48 chromosomes per cell). The results are discussed in relation to the origin of previously described variation among protoplast-derived potato plants and with respect to genetic engineering of tetraploid potato cultivars.

Survival of Nicotiana tabacum L. Cv. Wisconsin-38 plants regenerated from gamma-irradiated tissue cultures

Explants and callus tissues of haploid and diploid Nicotiana tabacum L. cv. Wisconsin-38 were treated with 2 kR of gamma radiation. The number of calli with buds was determined 42 days after irradiation. From a total of eight different treatment combinations three showed significant increases in number of calli with buds (95% level) and five experiments showed increases which were not significant at the 95% level. Bud regeneration was related to the survival of plants grown from these buds. Plants were considered “survived” when they attained the flowering stage. A decrease in the survival of plants regenerated from irradiated tissues was recorded in seven out of eight different treatment combinations. This effect was ascribed to the high sensitivity of cells with low chromosome number and death of plants during growth due to physiological disturbances.

WHITE FLOWER COLOR IN RAPE (BRASSICA NAPUS) ASSOCIATED WITH A RADISH (RAPHANUS SATIVUS) CHROMOSOME

The inheritance of flower color was investigated in progeny from crosses between a normal, yellow flowering rape strain (Brassica napus L.) and a white flowering strain developed at the University of Manitoba by backcrossing the white flower color from Raphanobrassica into B. napus. The chromosome number of all yellow flowering plants examined was normal (2n = 38), whereas all white flowering plants examined contained a single or a pair of small radish (Raphanus sativus L.) chromosomes each carrying a dominant gene(s) for white flower color. The homozygous white flowering rape strain was in fact an alien addition line (2n = 40) disomic for a pair of radish chromosomes. The transmission and meiotic behavior of this alien chromosome as a univalent was investigated in the progeny of crosses involving the white flowering F1 hybrid. Cytological observations of meiotic metaphase 1 indicated that the univalent should be transmitted with 24.6% of the gametes. This was in agreement with the observed transmission of 24.3% through the female gametes. Transmission through the pollen ranged from 22.1% to 0.7%, the variation in certation depending on the genetic constitution of the pistil and on the time of pollination. The vigor, fertility and true breeding nature of the white flowering strain suggested that the white flower color factor from the radish had been introgressed into the rape genome. Cytological observations were necessary to demonstrate that introgression had not taken place and to aid in the interpretation of the genetic ratios observed.

Isolation, Protoplast Culture, and Plant Regeneration of PFP-Resistant Variants of Nicotiana tabacum Sulsu

Summary p-Fluorophenylalanine (PFP) resistant variants of Nicotiana tabacum Sulsu were routinely isolated from rapidly growing suspension cultures by plating in the presence of 0.5 mM PFP. The PFP-resistant phenotypes of about 10% of the variants isolated were stable, and calli have retained resistance to PFP after more than one year in culture. Resistance was retained whether the cells were grown in the presence or absence of PFP. Calli of PFP-resistant cell lines were induced to regenerate shoots on MS medium with 5 µM 6-benzylaminopurine. In some PFP-resistant lines shoots were regenerated in the presence of 0.5 mM PFP. Shoot regeneration from PFP-resistant cell lines was only achieved shortly after their isolation. Although shoots could be rooted, the albino Su mutantion precluded transfer of the plants to soil. Suspension cultures of PFP-resistant cell lines retained the same chromosome number (2n = 48) of intact plants, even after several months in liquid culture. Protoplasts (isolated from suspension cultures established from calli of PFP-resistant cell lines) were cultured in the presence of 0.125 mM PFP, a concentration sufficient to inhibit cell wall regeneration and cell division of normal Sulsu protoplasts. Suitable conditions are therefore defined for the use of PFP resistance as a selective marker in recognition of somatic cell hybrids accomplished via protoplasts fusion.

Chromosome Races in Lophopogon tridentatus (Roxb.) Hack.

Preliminary studies in Lophopogon tridentatus (Roxb.) Hack. (Andropogoneae, Poaceae), disclose three different chromosome numbers in plants from three different localities: 2n = 8, 2n = 10, and 2n = 18. All localities are in India. Voucher specimens are deposited at the University of Mysore.

Isolation of diploid and tetraploid Sexual plants in guineagrass (Panicum maximum Jacq.)

Sexually leproduclng plants (sexual plants) of guineagrass were screened by progeny tests for progressing cross breeding in this apomictic species. Two hundreds and thirty four plants of 86 guineagrass accessions were self-pollinated by bagging and/or open-pollinated. Their progenies were space-planted in plot of ten or twelve plants in these tests. Hairiness on eight different organs and distinct changes of morphological traits were observed for scoring the variability within progeny. Two criteria of varia-bility, viz. number of plant types and number of plants belonging to the predominant plant type within a progeny, were adopted. Plant type is a group of plants in a progeny which showed the same or similar combination of scores given to the charac-ters. Determination of the mode of reproduction, sexual or apomictic, and estimation of the degree of sexual reproduction (sexuality) were made basing on the number of plant types and number of plants belonging to the predominant type. Out of 234 plants, 4 highly sexual plants and 2 Iowly sexual plants were isolated from 4 accessions. Sexuality of these 6 plants was ascertained by progeny test in the second generation. The isolated highly sexual plants produced highly sexual offsprings, non-segregating offsprings and a few or no lolvly sexual offsprings in their progenies. Lowly sexual platns produced lowly sexual offsprings and non-segregating offsprings. Chromosome numbers of sexual plants were counted in pollen mother cell or root-tip cell. Four highly sexual plants were classifled into one plant with 2n=32 chromosomes, two plants lvith 2n=16 chromosomes and one plant with 2n=18 chromosomes. Two 10wly sexual plants included one plant with 2n=32 chromosomes and one plant of unl.cnown chromosome number. Sexual plant with 2n=18 chromosomes was first dis-covered in the present studies. Prospect of utilizin*o' these sexual plants in combination with apomicts for breeding of this plant species lvas discussed

Chromosome Numbers of Hawaiian Flowering Plants and the Significance of Cytology in Selected Taxa

Chromosome numbers are reported for 128 species of flowering plants indigenous or endemic to Hawaii, including first reports for 13 genera and 82 species. The special significance of reports for Ilex, Tribulus, Keysseria, Pisonia, Boerhavia, Jacquemontia, Claoxylon, Lipochaeta, Railliardia, and Dubautia are discussed. The cytological and morphological variation in Railliardia and Dubautia is considered and their treatment as congeners is advocated. The cytogeogruphic pattern in Dubautia and Railliardia and other factors suggest that the ancestral chromosome number of the Hawaiian tarweeds is n = 14. Their derivation from a western North American progenitor similar to Adenothamnus is considered plausible if not indeed likely.

Cytogenetic studies in the <i>Eragrostis curvula</i> Complex

Cytogenetic studies were undertaken in the Eragrostis curvula Complex. Three plants were studied at each of 16 collecting points. The overall morphology and embryo sac development of all plants were evaluated, while the chromosome number and microsporogenesis of some of the plants were also studied. The collecting points were chosen so ^s to represent a variable environment extending from the bushveld to the highveld regions of the Transvaal. It was found that the embryo sac development of the plants from the bush\eld and the highveld were, for all practical purposes, obligate diplosporic apomicts, whereas the transition area contained obligate as well as facultative diplosporic apomicts. The same pattern also held as far as the plant morphology, chromosome number and microsporogenesis were concerned.

Production and Utilization of Anther‐Derived Haploids in Crop Plants1

The production of large numbers of haploid plants from the culture of immature anthers on chemically defined agar media is now possible with a number of plant species. Data are presented which illustrate that media formulation, environment under which plants produce anthers, anther culture environment, cytological stage of the microspores, and genotype of the cultured species influence the successful production of haploid plants by anther culture and should be considered in attempting to obtain haploid plants by anther culture in other species. Several methods are now being successfully used to double the chromosome number of haploid plants. Haploid plants and homozygous diploid derivatives from these haploid plants are being used in both practical and fundamental studies. Superior breeding lines in Nicotiana, characterized by changes in chemical and agronomic traits, have been developed by the haploid procedure. Haploid plant material is particularly useful in induced mutagenesis studies. Anther culture has also been instrumental in the development of nullihaploid, nullisomic, trisomic, and tetrasomic aneuploid stocks in Nicotiana tabacum.

INDEX TO PLANT CHROMOSOME NUMBERS

TAXONVolume 24, Issue 1 p. i-i Index to Plant Chromosome NumberFree Access INDEX TO PLANT CHROMOSOME NUMBERS First published: February 1975 https://doi.org/10.1002/j.1996-8175.1975.tb00319.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume24, Issue1February 1975Pages i-i RelatedInformation

Propagation of Asparagus through Shoot Apex Culture II. Light and Temperature Requirements, Transplantability of Plants, and Cyto-Histological Characteristics1

Abstract In propagating Asparagus officinalis L. through the method of shoot apex culture, apices of terminal buds of spears produced in vitro were found to be equally satisfactory as explants as those of lateral buds of spears obtained from the field. A maximum number of plants was obtained when the cultures were illuminated 4-20 hr daily with white fluorescent or Gro-Lux lamps at an intensity of 1000 lux. A constant 27°C temp was also optimum for plant formation in vitro. Histological examination revealed that roots arose adventitiously from callus which formed at the base of the explant, whereas spears originated from axillary buds. Successful transfer of plants from laboratory to soil required a prior reculture in a medium lacking NAA and with the light intensity increased to 3000 or 10,000 lux. Examination of the chromosome numbers of plants propagated through shoot apex culture showed that the original diploid status had been retained in every plant.

CHROMOSOME NUMBERS IN UMBELLIFERAE. IV.

Chromosome numbers are reported for 167 collections representing 100 taxa of Umbelliferae. More than four‐fifths of the counts apply to members of subfamilies Hydrocotyloideae (29) and. Saniculoideae (50); the remaining 21 belong to Apioideae. Chromosome numbers of plants belonging to 68 taxa are published here for the first time; chromosome numbers are verified for 23 taxa; and chromosome numbers differing from those published previously are reported in nine instances. No chromosome counts have previously been reported for 19 of the genera included. Polyploidy has been established for Azorella, Mulinum, Coaxana, Enantiophylla, and Tiozimia.

Triticale, a Man-Made Species of a Crop Plant

Triticale is a man-made crop resulting from a cross between wheat (Triticum) and rye (Secale). The name is derived from a combination of two scientific names. In the past wheat-rye hybrids probably have occurred many times where wheat and rye were growing together. Natural hybrids, which generally are sterile, still occur. Wilson (1875) in England probably reported the first successful man-made cross between wheat and rye, but the hybrid was sterile. Rimpau (1891) in Germarly obtained a fertile type Triticale. Btlt it wasn't till the technique of determining plant chromosome number was perfected that the fertile types were recognized as amphiploids, i.e. Triticale contained the somatic number of chromosomes of the wheat and rye parents. The Triticale strains with 56 chromosomes (42 from wheat and 14 from rye) are referred to as octoploid (8 X ) Triticale. Wheat-rye material tracing back to that of Meister (1921 ) who began working with Triticales in Russia, is still being grown experimentally in Kansas.

Erroneous Counts in the Index to Plant Chromosome Numbers

Erroneous Counts in the Index to Plant Chromosome Numbers