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  • Author or Editor: C.S. Tang x
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Cyperus kyllingia and Cyperus brevifolius are problematic turfgrass weeds in Hawaii. Both are closely related weed species with similar morphology and growth characteristics. C. kyllingia appears to be a more successful weed with regards to interference than C. brevifolius. Greenhouse experiments were conducted to compare the levels of interference exerted by C. kyllingia and C. brevifolius upon Cynodon dactylon turfgrass. C. kyllingia reduced the growth of C. dactylon by about 50 %, while C. brevifolius did not significantly reduce C. dactylon growth. These results correspond with the chemical profiles of C. kyllingia and C. brevifolius. Analysis has shown that C. kyllingia contains two sesquiterpenes which have been identified as potentially allelopathic components of Cyperus rotundus. C. brevifolius contains waxes and the two sesquiterpenes found in C. kyllingia are absent. This suggests that allelopathy may be the mechanism responsible for the different levels of interference exhibited by C. kyllingia and C. brevifolius, and these species may provide an important model for the study of allelopathy.

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Abstract

Anthocyanins in the spathes of Anthurium andreanum were identified as cyanidin 3-rhamnosyIgluco-side and pelargonidin 3-rhamnosylglucoside. Both pigments were present in the red cultivars, ‘Ozaki’, Kaumana', ‘Kozohara’, ‘Kansako No. 1’, and ‘Nakazawa’, and in the pink cultivar, ‘Marian Seefurth’. The orange cultivar, ‘Nitta’, and the coral colored ‘Tateishi Coral’ contained only pelargonidin 3-rhamnosylglucoside.

Open Access
Authors: , , and

Abstract

Spathe color is shown to be determined by relative concentrations of the anthocyanins cyanidin 3-rhamnosylglucoside and pelargonidin 3-rhamnosylglucoside in Anthurium andraeanum Linden ex Andre. A predominance of cyanidin 3-rhamnosylglucoside results in pink to dark red colors, whereas a predominance of pelargonidin 3-rhamnosylglucoside results in coral to orange. A flavone present in large and variable amounts was characterized but not demonstrated to have a modifying effect on cyanic shades.

Open Access

Abstract

In the article “Concentration of Anthocyanins Affecting Spathe Color in Anthuriums” by R.Y. Iwata, C.S. Tang, and H. Kamemoto [Journal 110(3):383–385], the Figure 1 caption was incorrect. The correct caption should read: Spathe color expressions of anthurium clones in relation to the proportions of cyanidin 3-rhamnosylglucoside and pelargonidin 3-rhamnosylglucoside expressed as OD per gram fresh weight. • Dark Red, ◯ Bright Red, △ Red, ⬣ Light Red, □ Pink, ▴ Light Coral, ≪ Coral, ▪ Orange.

Open Access

Abstract

Root exudates of guava (Psidium Guajava L. cv. Beaumont) grown in sand culture were collected on columns of XAD-4 resin attached to the nutrient solution circulation system of sand-cultured plants. The compounds were eluted from the resin columns with methanol and the eluates were concentrated. The root exudates were inhibitory to the radicle growth of both lettuce (Lactuca sativa L. cv. Anuenue) and bristly foxtail (Setaria verticillata L. Beauvois) and lettuce seed germination was inhibited. Fractionating the root exudates resulted in the neutral and acidic fractions being inhibitory, the basic fraction having no effect. Methanolic extracts of oven-dried guava roots were also inhibitory.

Open Access

Flowers emit volatile compounds that attract pollinators. In ornamental plant breeding programs, fragrance is a significant character that adds value to flowers for its consumer appeal. In Hawaii, anthurium (Araceae) is an important crop used for cut flowers and flowering potted plants. Unlike other ornamentals, fragrance is not presently associated with commercial anthuriums. However, several anthurium species are known to have distinctive scents. To obtain the novelty trait of fragrance in anthurium, an understanding of anthurium scent genetics, physiology, and chemistry is required. Scented anthurium species and hybrids in the Univ. of Hawaii germplasm collection have been studied. Fragrance emission among species varies with time of day—some species being scented only in the morning, only at night, or all day long. Fragrance emission also varies with stage of spadix development, with some species having scent as pistillate and/or staminate flowers. The species sampled comprise five categories: A. amnicola, A. formosum, and A. lindenianum are minty; A. armeniense is sweet; A. gracile is floral; A. bicollectivum, A. cerrobaulense, A. folsomii, and A. harleyii are fruity; and A. supianum is fishy. Some of the chemical components are illustrated.

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Abstract

Two anthocyanins from Anthurium amnicola (Dressler) were identified as cyanidin 3-rutinoside and peonidin 3-rutinoside. HPLC chromatograms from spathe and spadix were similar. Cyanidin 3-rutinoside occurred in much larger amounts than peonidin 3-rutinoside.

Open Access

The volatile compounds in soursop (Annona muricata L.) were obtained by a liquid-liquid continuous extraction procedure from the aqueous solution of blended soursop pulp and analyzed by gas chromatography (GC) and GC-mass spectrometry (MS). Twelve volatiles were identified by comparing their mass spectra and Kovats retention indexes with those of standard compounds: five were identified tentatively from MS data only, eight are being reported for the first time. (Z) -3-hexen-l-ol was the main volatile present in mature-green fruit, while methyl (E) -2-hexenoate, methyl (E) -2-butenoate, methyl butanoate, and methyl hexanoate were the four main volatiles present in ripe fruit. Concentrations of these five volatiles decreased and several other unidentified volatiles appeared when the fruit became overripe.

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