摘要:

Two varieties of wheat seed were sprinkled with solutions containing formaldehyde and naphthylacetic acid to give treatments of 1 and 10 parts of the latter to a million parts of seed by weight. In both varieties formaldehyde treatment reduced the germination rate, final germination count, and the air-dry weight of stems and roots at 29 days after planting. Some reduction in root suppression resulted from the 1 p.p.m. concentration of hormone; the higher level had no effect.The experiment involved the use of two preparations of naphthylacetic acid, differing only in respect to a trace of halogen in one. This impurity had no effect on final germination or stem and root weights, but increased the germination rate. The trace of halogen had the more marked effect at the highest concentration and the variety Marquis was affected to a greater extent than Reward.

ISSN:1923-4287    

DOI:10.1139/cjr40c-023

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

Glutelin is the only nitrogen fraction that is significantly correlated with starch, barley extract, and insoluble carbohydrate, between varieties. In each case the correlation coefficient barely attains the 5% level of significance. Within varieties the correlation coefficients for starch and barley extract with glutelin, hordein, and salt-soluble nitrogen are all negative and attain the 1% level of significance. Insoluble carbohydrate shows no intra-varietal associations with any of the nitrogen fractions.Starch and barley extract are very closely associated with malt extract both within and between varieties. Insoluble carbohydrate is closely related to malt extract between but not within varieties. It is shown that Bishop's principle of regularities in the carbohydrate and nitrogen composition within varieties fails to apply to insoluble carbohydrate. Intra-varietal associations of steeping time with starch,r = 0.797, barley extract,r = 0.730, and insoluble carbohydrate,r = −0.782, are not dependent on the total nitrogen of the barleys.Regression coefficients of malt extract on barley extract are homogeneous both within and between varieties, and the average varietal and station regressions do not differ significantly. It is shown that barley extract is more closely related to malt extract than either starch or insoluble carbohydrate, between varieties. Within varieties it affords a more accurate estimate of malt extract than either starch or total nitrogen.

ISSN:1923-4287    

DOI:10.1139/cjr40c-024

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

Colchicine treatments of the seed of a sterileF1hybrid of Vernal emmer ×A.glaucum(2n = 35) induced fertility through chromosome doubling. The F2plants were exceptionally vigorous, with abundant leafy foliage, and spikes producing an average of 48 seeds each, of which 83% were viable. These amphidiploid plants appear to be perennial, but so far have not been tested for winter hardiness.The establishment of amphidiploid sectors of sufficient size to make possible the production of seed depended on the successful competition of the amphidiploid with the undoubled tissue. Different hybrids varied greatly in this respect. A relation existed between growth vigour of amphidiploid sectors, or plants, and increase in stomatal size on chromosome doubling.Eight of elevenF2plants possessed 70 chromosomes and the remaining three, 64, 68, and 69. Meiotic studies on five of these plants revealed the formation of 27 to 31 bivalents, 6 to 9 univalents, and occasional trivalents and quadrivalents. Anthers of the amphidiploids dehisced abundant pollen, 94% of which was good, whereas anthers of the undoubledF1were unable to dehisce and contained only 2% good pollen.

ISSN:1923-4287    

DOI:10.1139/cjr40c-025

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

Further work has substantiated earlier findings that phosphatic fertilizers and farm manure will give adequate control ofPythiumroot rot of wheat in infested prairie soils. The improvement in growth resulting from these amendments is considered to be due to the production of a larger number of quicker growing roots which lessens the chances for infection and leaves more roots healthy, though the same percentage may be affected as in diseased plants showing severe leaf discolorations. Experiments have failed to indicate that the phosphatic materials increase resistance appreciably. Nitrogenous materials when applied singly had virtually no effect on growth, but once ample phosphorus was added, further nitrogen applications gave substantially greater increases than phosphate alone. Phosphorus is apparently the chief limiting element. No difference was found in preliminary tests in the phosphate-fixing power of browning and normal soils. Typical browning soils responded irregularly to small applications of boron, copper, manganese, or zinc, but were not found to be seriously lacking in these elements. Moderate benefits resulted from heavy applications of gypsum and of sulphur. Browning soil was found also to be deficient in phosphate for non-cereals such as alfalfa, buckwheat, carrots, flax, lettuce, and sweet clover. These crops were not attacked by thePythiumspp. pathogenic to cereals. Consequently the poor growth of the non-cereals in browning soil appears to be due to nutrient deficiencies, while the poor growth of cereals is due to both root-destroying fungi and nutrient deficiencies. In both instances phosphorus is probably the chief limiting element. Ground cereal straw, sweet clover hay, and weed hay amendments gave moderate increases m the growth of wheat. No consistent differences were found in the carbon-nitrogen ratios of browning and normal soils. The results as a whole suggest that two of the most practicable means of meeting the browning root-rot situation are, firstly, to supply supplemental nutrients in the form of artificial fertilizers, and secondly, to add organic residues or farm manure regularly to fields subject to the disease.

ISSN:1923-4287    

DOI:10.1139/cjr40c-026

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

The seedling reaction toPuccinia graminis Tritici, race 21, in the greenhouse was compared with the mature-plant reaction to all races present in the field, in three intra-durum crosses involving Iumillo.All lines that were resistant in the greenhouse were also resistant in the field. A large number of lines were susceptible at both stages. A third group contained lines susceptible in the seedling stage but resistant in the mature-plant stage. However, increasing susceptibility in the seedling stage, in general, indicated increasing susceptibility in the mature-plant stage. Most of the lines highly resistant at the mature-plant stage could have been selected on the basis of the seedling test.Iumillo appears to possess a factor or factors for mature-plant resistance as well as a factor or factors for resistance at both stages of maturity. The reaction to stem rust in the hybrid lines did not appear to be inherited in a simple Mendelian manner. This appeared to be due, in Iumillo × Mindum crosses, to the presence of the two types of resistance in Iumillo, while in the Pentad × Iumillo crosses the inheritance was complicated still further by the additional factors for resistance in the Pentad parent.The inheritance of seed colour was studied in a cross, Iumillo × Mindum. There appeared to be no correlation between seed colour and stem rust resistance. Seed colour in this cross was inherited in a simple 3:1 ratio, red-coloured seed being dominant.The results of this study indicate that simple and inexpensive greenhouse tests, in which but one physiologic race is used, may be employed to eliminate susceptible lines in the field in durum crosses involving Iumillo.

ISSN:1923-4287    

DOI:10.1139/cjr40c-027

出版商:NRC Research Press    

年代:1940

数据来源: NRC