摘要:

Germination tests on fruits derived from open, self, and cross pollinations made inUlmusduring four seasons strongly indicate a high degree of self sterility, possibly due to protogyny. It is suggested that a hybridization procedure involving the cross pollination of non-emasculated flowers is feasible in many species of the genus, especially under conditions that permit large-scale crossing and the growing of fairly extensive populations from which selfed seedlings may be eliminated.

ISSN:1923-4287    

DOI:10.1139/cjr46c-001

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

Tetraploid forms of the flax variety, Redwing, and the F1flax hybrid, Bison × Redwing, were most easily obtained by treatment of the epicotyl of seedlings with colchicine in lanolin emulsion. Seeds of the tetraploid forms were considerably larger than those of the diploid; but, because of their lower fertility and later maturity, yield and quality were definitely inferior.

ISSN:1923-4287    

DOI:10.1139/cjr46c-002

出版商:NRC Research Press    

年代:1946

数据来源: NRC

摘要:

Germination tests on seed of the 1939 crop ofAgrostis stoloniferaL. var.compactaHartm.,A tenuisSibth., andA.caninaL. 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.

ISSN:1923-4287    

DOI:10.1139/cjr46c-003

出版商:NRC Research Press    

年代:1946

数据来源: NRC