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- Author or Editor: Peter D. Ascher x
The snail flower, V. caracalla, was a popular ornamental flowering plant in conservatories at the turn of the century. It's popularity was due, in part, to its showy, orchid-like flowers whose fragrance rivals Stephanotis The indeterminate, vining growth habit can produce plants > 20 feet in height. V. caracalla is of interest for genetic and evolution studies since it is an ancestral species and possesses diagnostic traits of both Phaseolus (coiled style, leaf length/width ratios) and Vigna (> 10 seeds/ovary, long seed pods). However, its reproductive biology and use as an intergeneric hybrid bridge is unknown. Plants were examined for male and female fertility, self compatibility, and cross compatibility. Genotypes were self-incompatible; with one exception, self seed set did not occur following artificial manipulation. Selfed flowers abscised within 1-2 days post-pollination. Accessions were cross-compatible and highly fertile. To date, intergeneric hybridizations performed with P. coccineus --theancestral Phaseolus --have aborted following fertilization.
Lythrum species (Lythraceae), found both in the Old and New Worlds, possess heterostyly (macroscopic differences in anther and style lengths). SI is linked with heterostyly in tristylous L. salicaria, allowing for visual identification of compatibility relationships. Five Minnesota populations of distylous L. alatum (short & long styles/anthers) were examined for fertility and linkage between distyly and SI. Pollen was not inhibited from germination, stigmatic penetration, or stylar growth in compatible crosses. Average cross-compatible seed set for each population was 7-33 seeds/capsule for short- and 27-69 for long-styled plants. With the exception of the Iron Horse Prairie population, there were no significant differences in mean seed set/capsule between genotypes, style morphs, or their interaction for compatible crosses. Zero self seed set predominated, although 0.8±1.8 seeds/capsule were produced by short styles and 1.2 ±2.3 by long styles from Iron Horse Prairie. In those individuals that were SI, pollen tube growth was inhibited following self pollinations.
Abstract
Self progenies obtained from bud pollination or from self pollination following high temperature treatment of 7 self incompatible (SI) Petunia hybrida Vilm. plants representing the I1, I4, I6, and I7 generations were tested for SI in both summer and winter greenhouse environments. Five exhibited increased self seed set (pseudo-self compatibility, PSC) after winter pollinations, 1 was more PSC after summer pollinations, and 1 set no self seed in either pollination environment. Comparison of sibling progenies within a line at the I8 generation and differences in PSC between lines at the I7 and I8 generations indicate that inbreeding has not destroyed the possibility of recovering SI.
Abstract
Injection of 100 or 200 ppm 6-furfurylaminopurine (kinetin) into detached Lilium longiflorum (Easter lily) styles before pollination removed the differential pollen tube growth attributable to the self-incompatibility reaction so that both compatible and incompatible pollen tubes reached lengths typical of compatible tubes. Prepollination injections of 50 ppm kinetin produced variable results while injection of 1 or 10 ppm kinetin had no effect on pollen tube growth.
Abstract
The exudate produced on the stigma of mature flowers of L. longiflorum Thunb. did not adversely affect pollen tube growth or the self-compatibility reaction when injected into lily styles before, 6, or 12 hr after pollination. Stigmatic exudate diluted with an equal volume of distilled water before addition to the style had no effect on pollen tube growth when injection occurred before or 6 hr after pollination. Although injection of exudate alone 24 hr after pollination or injection of diluted exudate 12 or 24 hr after pollination retarded pollen tube growth, the addition of exudate or diluted exudate did not obscure the self-incompatibility reaction. Stigmatic exudate appears to be an excellent milieu in which to carry exogenous materials into the environment of pollen tubes of L. longiflorum growing in vivo.
Abstract
Compatibly- and incompatibly-pollinated detached styles of Lilium longiflorum were incubated for various time periods at 39°, 31°, 24°, 19° and 12.5°C to elucidate the effect of high and low temperatures on the self-incompatibility reaction. High temperatures during pollen tube growth prevented the incompatibility reaction, as incompatible pollen tubes reached lengths similar to those of campatible tubes in styles incubated at 39° and 31°C. Between 12 and 24 hr post-pollination the rate of compatible tube growth at 24°C (room temp) doubled while the rate of incompatible tubes continued unchanged. Incompatible pollen tube growth decelerated after 2 days at 19°C resulting in a significant difference between compatible and incompatible tube length 3 days after pollination. In styles incubated at 12.5°C the lengths of compatible and incompatible pollen tubes did not differ significantly until 6 days after pollination when incompatible tubes were shorter. The self-incompatibility reaction occurred at low temperatures, for growth of incompatible tubes was restricted to lengths typical of those grown at room temperature.
Abstract
An average Easter lily bulb with 100 scales may produce 8000 or more bulbs in 6 weeks when 1 mm thick cross sections from the scales are cultured in the Linsmaier-Skoog medium as modified by Sheridan and supplemented with 0.03 mg/liter NAA. Continuous darkness at 25°C increased bulb number and size at the expense of leaf number and size while a cycle of 16 hours cool white fluorescence at 1.6 klx (150 ft-c) and 8 hours dark at 25°C suppressed bulb formation but enhanced leaf formation, root weight, and fresh weight of callus. Root numbers were equal in both environments. Cultures incubated at 18.3° exhibited no measurable growth after 6 weeks. Explants from the distal part of the bulb scale will grow only with growth regulators present.
Abstract
Bulblets of Lilium longiflorum generated in vitro in the dark at 30°C produced leaves more rapidly and more completely after transplanting to vermiculite than those generated in vitro at 25°. The product of temperature × time (days) was equalized by varying the number of days at the 2 temperatures to make treatments comparable. Therefore, the effect of temperature in vitro was not due to a linear relationship between bulblet development and the product of temperature × time. Bulblets formed at 30°C for half of the temperature × time product of the tissue culture period produced leaves after transplanting at rates similar to those of bulblets generated at a constant 30°C. Exposure of bulblets generated in vitro at 25°C to 4° for 2 weeks before planting in vermiculite resulted in leaf production not significantly different from that of chilled or non-chilled bulblets generated in vitro at 30°C. However, chilling significantly increased fresh weight of bulblets produced in vitro at either temperature. The data suggest that temperature during in vitro development affects Easter lily bulblet dormancy as measured by leaf production.
Abstract
Bulblets from bulb-scale explants of Lilium longiflorum Thunb. cvs. Ace and Nellie White cultured in darkness on a semisolid Linsmaier-Skoog medium supplemented with 0.03 mg/liter α-naphthalene-acetic acid (NAA) bore no leaves when produced in vitro at constant 30°C but often did when produced at constant 25°. In vitro temperature regimes involving both 25 and 30° resulted in the largest number of leaves per explant. Time in vitro in each temperature regime was calculated to provide equal heat units so that differences could not be explained by a linear relationship between development and temperature × time. Physiological state of explants, measured by time lily bulbs were stored at 4° before tissue culture, interacted with in vitro temperature. Explants from bulbs stored 110 days or less produced significantly fewer but significantly larger bulblets at constant 25° as compared to constant 30°. This difference was not apparent when explants were taken from bulbs stored at 4° more than 110 days. In an experiment with explants from bulbs stored 80 days, there was no significant difference between ‘Ace’ and ‘Nellie White’ in number of scales per bulblet at either 25 or 30° but bulblets of both cultivars contained significantly fewer scales if generated at 30°. Mean width of meristems in ‘Ace’ bulblets was significantly greater when produced in vitro at 30°. Neither initiation of bulblets nor bulblet development appeared controlled by apical dominance.
Abstract
Polyacrylamide gel disc electrophoresis of crude protein extracted at room temperature from various plant tissues with 10 to 90% dimethyl sulfoxide (DMSO) in water (v/v) resulted in clear, reproducible protein and isozyme banding patterns. Degeneration of samples stored at -29°C, as indicated by gradual discoloration, began 1 month after freezing in samples extracted with 10-20% and 6 months to 1 year after freezing in samples extracted with 30-60% DMSO. Banding patterns of gels run with discolored samples reflected the degradation in missing bands and indistinct band boundaries. Tissue extraction at 0°C with DMSO did not improve protein patterns in the gels.