PERSILANGAN INTERSPESIFIK ANGGREK HITAM (Coelogyne pandurata) DENGAN ANGGREK MUTIARA (Coelogyne asperata)

Black orchid (Coelogyne pandurata) and Pearl orchid (Coelogyne asperata) are endemic orchid from Kalimantan forest, shape and color suitable as ornamental flower. Many people collected the orchids from the wild for commercial purpose but not much effort on their propagation. To prevent population decreased, propagation and production of new varities via interspesific hybridisation need to be done. An important step required in plant breeding is to obtain cross compatiblity. Cross compatibility of some orchids from Indonesia are not known, including compatibility of Coelogyne pandurata x Coelogyne asperata. Information on compatibility and fertility is very important to produce good quality seed as propagation material. In this research pollination was performed on orchid plants at 2 until 5 day after flowering and pollination was done in the morning. There are three replicates for each pollination. Pollination was done with C. pandurata (black orchid) as male parent and C. asperata (pearl orchid) as female parent. The results showed that successful pollination was obtained from pollination at 2 days after flowering. Seed capsule was harvested at 3 months after pollination but not yet perfectly ripe. Seed germination employed in vitro method on Vacin & Went (VW) and VW with modification media. Seed from C. pandurata x C. asperata abled to germinate on VW media with addition of 0,1 mg/l auxin and 0.1 mg/l cytokinin and germinated 9 weeks after planting.

Fatty Acid Composition of Ripe Seed Oil of Nyctanthes Arbor-tristis L.

The fatty acid composition of the ripe seed oil of Nyctanthes arbor-tristis L. (Bengali: Seuli) were determined by GLC. The major constituent of the oil was found to be stearic acid, 39.06%. The relative percentages of other major fatty acids were found to be lauric acid, (4.46); linoleic acid, (7.89); oleic acid, (7.97). The yield of the seed oil was found to be 7.29% on extraction with pet-ether (b. p. 40°C - 60°C). Acid value of seed oil was found to be 55.44 and suggests that this oil is inedible.DOI: http://dx.doi.org/10.3329/jbas.v35i1.7977Journal of Bangladesh Academy of Sciences, Vol.35, No.1, 121-124, 2011

Effect of desiccation temperature on viability of immature dandelion (Taraxacum agg.) seeds dried in mowed inflorescences

After flowering has ceased, dandelion (Taraxacum agg.) capitula close to enable maturation of seeds. In late summer the period of seed maturation lasts for 9 days. The capitula mowed later than 4 days after the start of this period and desiccated at 25°C produce viable seeds. If cut and prostrated on insolated ground inflorescences can experience temperatures exceeding 50°C which may impair seed viability. We determined the effect of desiccation temperature (5, 15, 25, 35, 45 or 55°C) on viability of ripening seeds using inflorescences harvested on September 5, 2008 at Prague-Ruzyne (50°05'N, 14°18'09 E), five days after flowering ceased (about 4 days before seed dispersal). As control, ripe seeds were collected at dispersal on the same day and desiccated at identical temperatures. Desiccated seeds were germinated at constant 17°C. Ripening seeds of maturing capitula only remained germinable if desiccation temperatures were ≤ 35°C (optimum 25°C) and were killed at 45 and 55°C. The viability of ripe seed was not affected by any of the desiccation temperatures. Time of germination of 50% seeds that germinated was significantly shorter in ripe than ripening seeds. Exposure of mowed dandelion inflorescences on insolated ground (solarization) may thus decrease production of viable seeds because of high temperatures experienced during desiccation.  

Effects of Fruit Maturity, Storage, Presoaking, and Seed Cleaning on Germination in Three Species of Palms

Green, half ripe and ripe fruit of queen [Arecastrum romanzoffianum (Cham.) Becc.], pygmy date (Phoenix roebelenii O'Brien) and royla palms [Roystonea regia (HBK) O. F. Cook] were cleaned or left uncleaned and were presoaked in 1000 mg/1 gibberellic acid (GA,) for 48 hr, water for 48 hr, were not presoaked. Queen palm seed germinated best if cleaned green or half-ripe seed was used, but pygmy date and royal palm seed germinated best when cleaned half-ripe or ripe seed was used. Cleaned seed of these palms can be stored in sealed polyethylene bags at 23°C (73°F) for 4 to 9 months. Depending on the species, and royal palm seed benefited from storage of up to 9 months, presumably due to immature seed embryos at time of harvest.

Contributions to the biology of Mulga. I. Flowering

In spite of its wide distribution in arid Australia and its importance to the pastoral industry, mulga (Acacia aneura Benth.) has not been the subject of any detailed investigations to determine the climatic requirements for regeneration. An investigation of these requirements for flowering and seed set, in which trees growing in the field were given additional water for a period of 12 months, showed that flowering occurred several times in the year but that the principal flowerings were in spring and late summer. It was not shown definitely that rain was necessary to bring about flowering at these seasons, although the results suggested that flowering was heavier and seeding more successful when additional water, or good rains, reduced the normally severe water stress. Of the two principal flowering seasons, only the late summer one led on to seed set and the shedding of ripe seed. From rainfall records and values for the climatic requirements derived from observations made during the investigation, it was estimated that seed could have been set successfully once every six years in the experimental area since records began around 1890.

GERMINATION OF SEEDS OF THREE SPECIES OF AGROSTIS

Germination tests on seed of the 1939 crop of Agrostis stolonifera L. var. compacta Hartm., A tenuis Sibth., and A. canina L. were begun in September of the same year and carried through to May, 1940, with the object of studying the drift, with time, of germination capacity and germination speed under different conditions.Seeds of the three species proved to be highly light-sensitive but low light-requiring. Germination capacity was proportional to light intensity while germination speed was inversely proportional to light intensity. The possibility that excess of light (> 200 ft-c. for seven and one-half hours daily) might depress germination capacity was suggested. There was no significant difference, in their effect on germination, between Mazda and Fluorescent "Daylite" illumination at equal foot candle intensity.Potassium nitrate in 0.2% solution proved more effective than light in promoting germination in not fully germinating-ripe seeds but its use did not stimulate germination beyond the natural limits of fully ripe seed; thus its use in seed control laboratories is justified for these species. Its effect on the seed is clearly distinct, physiologically, from that of light.An interesting phenomenon was observed, consisting in a falling off in germination capacity accompanied by an absolute increase in germination speed during the period February–March.Seeds of these species fall into four classes. The interrelationships between these classes and changes within them and their connection with the February–March phenomenon are discussed in the text.