Cytology and breeding behavior of interspecific hybrids and induced amphiploids of Zinnia elegans and Zinnia angustifolia

1984 ◽  
Vol 26 (1) ◽  
pp. 40-45 ◽  
Author(s):  
Veronica M. Terry-Lewandowski ◽  
Gary R. Bauchan ◽  
Dennis P. Stimart
Keyword(s):  
Disease Resistance ◽  
Interspecific Hybrids ◽  
Colchicine Treatment ◽  
Zinnia Elegans ◽  
Breeding Behavior ◽  
Contributing Factors ◽  
Zinnia Angustifolia ◽  
Partial Homology ◽  
Partial Fertility ◽  
Homoeologous Chromosomes

Cytological studies were performed on interspecific hybrids and induced amphiploids of Zinnia angustifolia HBK (2n = 22) and Zinnia elegans Jacq. (2n = 24) to ascertain their potential in serving as intermediaries in the transfer of genes for disease resistance. Partial fertility was restored in sterile F1 hybrids (2n = 23) through colchicine treatment of axillary buds. Lagging univalents and irregular distribution of chromosomes to the gametes were the major contributing factors to the sterility observed among the F1 hybrids. Bivalent associations in the F1 indicated partial homology between parental genomes. The induced amphiploids (2n = 46) formed predominantly bivalents at metaphase I owing to the suppression of pairing between homoeologous chromosomes. Consequently, these segmental allopolyploids resembled diploids in their cytological and genetic behavior and bred true to their intermediate condition with little or no segregation in later generations. It is postulated that the gene(s) controlling chromosome pairing is derived from Z. elegans. The cytological and genetic performance of colchicine-induced amphiploids of Z. elegans and Z. angustifolia suggest considerable potential for the improvement of Z. elegans cultivars with respect to disease resistance and the immediate stabilization of characters through genetic uniformity.

scholarly journals Colchicine-induced chromosome doubling in Pennisetum interspecific hybrids and its effect on plant morphology

2020 ◽  
Vol 80 (01) ◽  
Author(s):  
Arshpreet Kaur ◽  
Rahul Kapoor ◽  
Yogesh Vikal ◽  
Anu Kalia
Keyword(s):  
Interspecific Hybrids ◽  
Biomass Yield ◽  
Chromosome Doubling ◽  
Plant Morphology ◽  
Colchicine Treatment ◽  
Stem Cuttings ◽  
Chromosome Counting ◽  
Stomatal Frequency ◽  
Preliminary Screening ◽  
Stomata Size

We report the production of hexaploid plants of interspecific hybrids of Pennisetum, with the ultimate aim to improve the biomass yield, drought tolerance and multicut behaviour of this genus. Chromosome doubling was achieved with the application of colchicine at three different concentrations (0.05, 0.1 and 0.2%) for two time durations (12 and 24 hours). The root slips and stem cuttings of interspecific hybrids were used for treatment and the root slips were found to be more efficient. The preliminary screening to select the putative hexaploid plant was done based on stomatal frequency and morphology. Plants containing significantly lower stomatal frequency and larger stomata size were selected for further analysis by chromosome counting. This experiment confirmed that 0.1% concentration of colchicine treatment to root slips for 24 hours was more effective to induce the amphiploids in Pennisetum.

INTERSPECIFIC HYBRIDS INVOLVING ALFALFA. VI. INEFFECTIVENESS OF ALLOPLOIDY IN INDUCTION FERTILITY IN MEDICAGO PIRONAE × M. DAGHESTANICA HYBRIDS

1971 ◽  
Vol 13 (3) ◽  
pp. 437-442 ◽  
Author(s):  
K. Lesins
Keyword(s):  
Interspecific Hybrids ◽  
Seed Set ◽  
Interspecific Cross ◽  
Pollen Grains ◽  
Colchicine Treatment ◽  
Plant Meiosis

Colchicine treatment of hybrids from the interspecific cross Medicago pironae Vis. × M. daghestanica Rupr. induced the formation of three tetraploid shoots, one with 2n = 29 and two with 2n = 32, in their somatic nuclei. Their flowers had 21, 44 and 62% plasma-filled pollen, respectively. No seed was obtained from these tetraploids after selfing and intercrossing more than 1,200 flowers, indicating the presence of a built-in fertility barrier between the two species.By applying pollen from the tetraploid hybrids to alfalfa (M. sativn L.) two trispecies hybrids with 2n = 34 and 30 chromosomcs were produced. The first had 32%, the second 22% plasma-filled pollen grains. On backcrossing to M. sativa, a higher seed set was obtained with pollen from the 2n = 34 plant than from the 2n = 30 plant. Meiosis in the 2n = 30 plant was abnormal. At MI multivalents were observed, indicating that chromosomal material may be interchanged between M. pironae-daghestanica and M. sativa. Approximately half the meiocytes at AI possessed lagging chromosomes and only 6% of secondary meiocytes at AII were without disturbances.

Molecular cytogenetic identification of B genome chromosomes linked to blackleg disease resistance in Brassica napus × B. carinata interspecific hybrids

2014 ◽  
Vol 127 (6) ◽  
pp. 1305-1318 ◽  
Author(s):  
Rudolph Fredua-Agyeman ◽  
Olivier Coriton ◽  
Virginie Huteau ◽  
Isobel A. P. Parkin ◽  
Anne-Marie Chèvre ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Brassica Napus ◽  
Interspecific Hybrids ◽  
Blackleg Disease ◽  
Molecular Cytogenetic ◽  
B Genome

Breeding behavior and chromosome numbers among New Guinea and Java Impatiens species, cultivated varieties, and their interspecific hybrids

1974 ◽  
Vol 52 (5) ◽  
pp. 923-925 ◽  
Author(s):  
Allan R. Beck ◽  
Jack L. Weigle ◽  
Eric W. Kruger
Keyword(s):  
Chromosome Numbers ◽  
Interspecific Hybrids ◽  
New Guinea ◽  
Chromosome Morphology ◽  
Breeding Behavior ◽  
Chromosome Counts

Impatiens crosses were made among the following: P.I. 349629 (Java), P.I. 349586 (New Guinea), I. Itolstii, and "Tangerine." All crosses were successful except those made with I. Itolstii. Chromosome counts were as follows: P.I. 349629 = 16, P.I. 349586 = 32, I. Itolstii = 16, and "Tangerine" = 8. Chromosome counts of the hybrids were midway between the respective parents. Cytological studies indicated a similarity in chromosome morphology and size among all parents except I. holslii. A new genome count of 4 is reported for the genus Impatiens indicating a ploidy series in which x = 4.

scholarly journals Aegilops × Secale hybrids: the production and cytology of diploid hybrids

1971 ◽  
Vol 17 (1) ◽  
pp. 17-31 ◽  
Author(s):  
B. N. Majisu ◽  
J. K. Jones
Keyword(s):  
Embryo Culture ◽  
Interspecific Hybrids ◽  
Diploid Species ◽  
Genetic Mechanism ◽  
Genetic Incompatibility ◽  
Homologous Chromosomes ◽  
Homoeologous Chromosomes

SUMMARYHybrids between four diploid species of Aegilops and species of Secale were obtained by using embryo culture. There was a marked incompatibility in the crosses between Secale species and each of the four species in Section Sitopsis of Aegilops and Ae. mutica. It is suggested that this genetic incompatibility with Secale species is an additional similarity between these species of Aegilops and the diploid species of Triticum.Most chromosomes of Aegilops (A) and Secale (S) are univalent during meta-anaphase of meiosis in these hybrids, but some appeared to associate and others to pair as apparently normal chiasmate bivalents. Analysis of non-chiasmate and chiasmate associations showed that the frequencies of autosyndetic (AA and SS) and allosyndetic (AS) associations fitted the 3AA: 7AS: 3SS ratio expected if association and pairing is at random. Any deviations from random involved a deficiency rather than an excess of Aegilops-Secale pairing. There is no evidence that the chromosomes of Secale are homologous with those of Ae. caudata, Ae. comosa and Ae. umbel-lulata, and it is suggested that the genome of Secale species does not show any homology with the genomes of the genera Aegilops. This does not preclude the presence of homologous segments. It is suggested that the possibility of random association of chromosomes should be considered when occasional pairing in interspecific hybrids is analysed, and that identification of chromosomes and recognition of chiasmata are required. The possibilities of chiasmata between non-homologous chromosomes, of a genetic mechanism in rye which suppresses the pairing of homoeologous chromosomes, and of other factors causing asynapsis and pseudo-synapsis between genetically similar chromosomes are discussed.

Interspecific hybrids of Zinnia elegans Jacq. and Z. angustifolia HBK: embryology, morphology and powdery mildew resistance

Euphytica ◽  
1982 ◽  
Vol 31 (3) ◽  
pp. 857-867 ◽  
Author(s):  
Thomas H. Boyle ◽  
Dennis P. Stimart
Keyword(s):  
Powdery Mildew ◽  
Interspecific Hybrids ◽  
Powdery Mildew Resistance ◽  
Zinnia Elegans ◽  
Mildew Resistance

scholarly journals Restoring Fertility for Novel Interspecific Hybrids between Kalanchoe garambiensis and K. nyikae Using Colchicine Treatment

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 209
Author(s):  
Yi Kuang ◽  
Chi-Hsuan Lu ◽  
Fu-Chiun Hsu
Keyword(s):  
Interspecific Hybrids ◽  
Hybrid Sterility ◽  
Colchicine Treatment ◽  
Tropical Species ◽  
Breeding Programs ◽  
Apical Buds ◽  
Environmental Adaptations ◽  
Reciprocal Crossing ◽  
Long Stem ◽  
First Time

Interspecific hybridization is an effective strategy in Kalanchoe breeding programs for the introduction of new traits. Wild species within the Kalanchoe genus are valuable genetic resources for providing new horticulture traits and to improve environmental adaptations. However, reproductive barriers associated with fertilization and hybrid sterility must be overcome to produce fertile hybrid progenies. To approach the breeding objectives for Kalanchoe cut flower cultivars with long stem traits and adaptation to tropical/subtropical regions, a tropical species endemic to Taiwan, Kalanchoe garambiensis Kudo, was used as a parent to cross with other long stem Kalanchoe species. Reciprocal crossing was effective in overcoming interspecific unilateral incompatibility in our crossed pairs. One superior hybrid, ‘103-1’, produced capsules without seeds by selfing and backcrossing with pollens from either parent. Other than the seedless trait, failure of pollen releasing from anther, pollen aggregation and no pollen germination in ‘103-1’ suggested its F1 sterility. Colchicine treatments on apical buds of ‘103-1’ successfully overcame potential meiotic abnormalities by doubling ploidy. For the first time, fertile interspecific hybrids of K. garambiensis and K. nyikae Engler were generated. The fertile hybrid has further produced progeny populations by crossing with K. nyikae or K. blossfeldiana von Poelln, ‘Ida’.

Evaluation of Disease Resistance among 57 Varieties of Zinnia elegans

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 467a-467
Author(s):  
Linda Gombert ◽  
Susan Hamilton ◽  
Mark Windham
Keyword(s):  
Disease Resistance ◽  
Powdery Mildew ◽  
Xanthomonas Campestris ◽  
Disease Susceptibility ◽  
Growing Season ◽  
Zinnia Elegans ◽  
Field Conditions ◽  
Uniform Field ◽  
Bedding Plants ◽  
Susceptibility And Resistance

Fifty-seven of the most widely grown, commercially popular varieties of Zinnia elegans were evaluated for disease susceptibility under uniform field conditions. Plants were started from seed and transplanted into cell-packs to be grown on as bedding plants. They were later transplanted into the field and observed for development and progression of the diseases alternaria blight (Alternaria zinniae), powdery mildew (Erisyphe cichoracearum), and bacterial leaf and flower spot (Xanthomonas campestris pv. zinniae). Evaluations were performed throughout the growing season in order to rate each variety on its susceptibility to disease based upon severity of infection as well as portion of plant affected. Results will be presented on disease susceptibility and resistance of the 57 varieties evaluated.

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