; Parkinson, 1629 ), offer a high-end product for the commercial grower, and an insight into the genes involved in floral development for the academic. However, these sterile double forms can only be propagated through vegetative means. Vegetative propagation
Sadiye Hayta, Mark A. Smedley, Jinhong Li, Wendy A. Harwood and Philip M. Gilmartin
Jaroslav Ďurkovič, František Kačík, Miroslava Mamoňová, Monika Kardošová, Roman Longauer and Jana Krajňáková
). The objectives of this study were: 1) to determine whether routinely applied vegetative propagation techniques that maintain true types of elm genotypes (i.e., in vitro micropropagation vs. widely used grafting of past decades) would affect lignin
Jaroslav Ďurkovič, Ingrid Čaňová, Lucia Javoříková, Monika Kardošová, Rastislav Lagaňa, Tibor Priwitzer, Roman Longauer and Jana Krajňáková
for this study were 1) to determine whether routinely applied vegetative propagation techniques that maintain true types of elm genotypes tolerant to DED (i.e., in vitro micropropagation vs. widely used grafting of past decades) would affect the
Kathryn M. Santos, Paul R. Fisher, Thomas Yeager, Eric H. Simonne, Hannah S. Carter and William R. Argo
percent nutrient concentrations, suggesting that nutrient concentrations in the stock plant are very important to avoid nutrient deficiency symptoms in the unrooted cuttings ( Rowe and Blazich, 1999 ). The goal throughout vegetative propagation is to
M. Pooler and P.W. Simon
Despite its long history of obligate vegetative propagation, garlic (Allium sativum L.) exhibits a surprisingly large amount of variation between clones, as evidenced by both morphological and isozyme markers. As reported previously, several garlic clones which produce viable seed have been identified in the Wisconsin collection, and a possible correlation between clone fertility, morphology, and isozyme banding patterns was examined. The potential use of isozymes to analyze sexually-derived hybrid garlic lines, haploids, and interspecific hybridizations was also investigated.
D.E. Kester, T.M. Gradziel, K.A. Shackel and W.C. Micke
Noninfectious bud-failure (BF) is a genetic disorder in almond, associated with nursery source selection. Previously (Kester, PASHS, 1968), the latent potential for BF (BFpot) was shown to be heritable but its phenotypic expression (BFexp) varied among individual seedlings of a populations as a function of age. Vegetative propagation perpetuates BFpot of individual propagules (Kester and Asay, JASHS, 1978b) but the subsequent age of BFexp within individual plants is a function of accumulated exposure to high summer temperature and growth (Kester and Asay, JASHS 1978a). A recent 7-year “somatic heritability” study of 12 commercial nursery sources (Kester et al., HortScience 1998abst) portrays the total range of variability of BFpot and BFexp within the entire `Carmel' almond clonal population and includes a pattern of BF increase in consecutive vegetative propagation cycles that mimics patterns produced by phase change (i.e., juvenile > mature) phenomena (Hartmann et al., 1997). Although phase change potential is heritable in seedling populations, phase change expression is not (Kester, HortScience 1983). Furthermore phase changes can be reversed under particular conditions during consecutive vegetative propagations (Hartmann et al., 1997). In contrast, evidence shows that BF produces permanent changes in genotype that are heritable and irreversable. High correlations exist between BFpot of individual source blocks, individual trees and individual budsticks and the age and severity of BFexp in progeny trees. The apparent continuous change in BFpot and BFexp within clones appears to be the pattern of expression of different populations of increasingly defective (?) somatic cells that result from consecutive sequences of change during annual cycles of growth and generations of vegetative propagation.
José E.B.P. Pinto, Clovis M. Souza and W.R. Maluf
Hybrid cabbage cultivars can be produced via seed-propagated self-incompatible (SI) inbred lines, or, alternatively, via vegetative propagation of SI clones. Cabbage clones differ in their ability to undergo vegetative propagation, a fact that appears to be related to the degree of differentiation of the axillary buds inside the head. A procedure for in vivo and in vitro propagation is described for cabbage clones known for difficulty in undergoing vegetative propagation. Cuttings from clonal families 800 (easy-to-propagate) and 007 (difficult to propagate) were immersed in indolebutyric acid (IBA—0, 5, 25, and 125 mg·L–1) + boric acid (100 mg·L–1) + sucrose (20 g·L–1) for 15 hours and maintained in glasshouses. Induction of roots was more effective with 125 mg·L–1 IBA supplemented with boric acid and sucrose. This treatment showed the highest frequency of rooting and the largest number of roots per cutting. The in vitro system of propagation was performed on the basal medium of Murashige and Skoog (MS), to which triadizuron (TDZ), benzyladeninepurine (BAP), and kinetin (Kin) were added in different combinations. TDZ was more effective than BAP or Kin in the promotion of shoot regeneration.
T.M. Gradziel and W. Beres
A single seedling exhibiting a semidwarf growth habit was found in an open-pollinated clingstone peach [Prunus persica (L.) Batsch] population. The growth habit was upright and open, with short, spur-like lateral branching. Tree size was about half that of its siblings as a result of shorter internodes. The total number of nodes on first-order branches was not significantly different from that on standard-sized trees. The semidwarf growth habit remained stable after vegetative propagation. Segregation in sexual progeny showed the trait to be highly heritable.
Douglas W. Maxwell and R. Daniel Lineberger
Research was undertaken to optimize seed storage and vegetative propagation of Camptotheca acuminata. Camptotheca is a member of the Nyssaceae native to southern China and is important because it contains the medicinal alkaloid camptothecin. Seeds stored in polyethylene bags in a refrigerator (4 °C) or freezer (- 20 °C) maintained good germination (79% and 83%, respectively), while seeds stored at room temperature in open containers or polyethylene bags lost germination ability quickly (45% and 51%, respectively). Softwood cuttings of Camptotheca rooted readily in intermittent mist (4 s on every 6 min.) in coarse vermiculite when treated with K-IBA (indolebutyric acid, potassium salt) quick dips ranging from 1000 to 9000 ppm, with a 7000 ppm quick dip (5 s) promoting 82% rooting with little foliar damage. Actively growing shoot tip explants were tissue cultured on media containing Murashige and Skoog, Gamborg, and Woody Plant Medium (WPM) salts in factorial combinations with BA (benzyladenine). WPM containing 1.0 mg/lBA promoted excellent shoot proliferation; microcuttings were rooted, acclimated, and grown on in the greenhouse. Camptotheca is readily adaptable to modern nursery techniques for either seed or vegetative propagation.
Daniela Salvini, Silvia Fineschi, Roberta Pastorelli, Federico Sebastiani and Giovanni G. Vendramin
Twenty populations of the species aggregate Rubus fruticosus were collected throughout European natural forests and analyzed by chloroplast microsatellites (SSR). Results showed high genetic diversity (h T = 0.73) and haplotipic richness (17 haplotypes were detected), and the presence of several unique alleles. The value of genetic differentiation between populations was low for unordered alleles (G ST = 0.29) and for ordered alleles (N ST = 0.30), revealing the absence of phylogeographic structure of the haplotypic diversity. This can be mainly ascribed to the mechanisms of seed dispersal, mostly mediated by animal ingestion, which are responsible for a efficient gene flow through seeds. Rubus L. species are characterized by the ability to colonizing disturbed, but also intact forest communities, rapidly propagating though suckering and hybridizing with native species. Our results suggest that efficient seed dispersal can counterbalance the effects of vegetative propagation, maintaining a high genetic diversity.