Red Bobs Research Articles

EFFECTS OF VARIETY AND DATE OF SEEDING SPRING WHEATS AND LOCATION IN THE FIELD ON SEX RATIO OF THE WHEAT STEM SAWFLY, CEPHUS CINCTUS NORT. (HYMENOPTERA: CEPHIDAE)

The sex ratio of the wheat stem sawfly, Cephus cinctus Nort., was affected by date of seeding, variety, and distance from source of infestation but not by diameter of host stem. The results suggest that the sex ratio of the progeny depends on the proportion of adults that are males and hence on the amount of fertilization of the eggs at the time of oviposition; increased percentages of male adults increase percentages of female progeny. Most adults at the beginning of the flight period are males whereas, at the end, most are Females. Most progeny from the earliest-seeded plants, which are infested first, were females, whereas most from the latest-seeded, which are infested last, were males. Red Bobs wheat develops more rapidly than Thatcher and is infested earlier; more female progeny emerged from Red Bobs than from Thatcher. The percentages of female progeny were highest from the margins of the fields evidently because most male adults remained there.The sex ratios of sawflies from different dates of seeding of the resistant wheat Rescue were not consistent with those from the susceptible wheats. The inconsistencies were evidently caused by differences in survival of the individuals in different locations in the resistant stems. In susceptible wheats the first-laid were most likely to survive, whereas in resistant wheats location rather than time of oviposition determined survival.

Monosomic and Conventional Gene Analyses in Common Wheat

Genetic control of growth habit and awnedness in common wheat was studied by the aneuploid and the conventional methods of analysis. Using the 21 monosomic lines of the spring variety, Chinese Spring, as female parents, crosses were made with seven varieties. In addition, diallel crosses were made among the seven varieties and Chinese Spring.Growth habit was found to be controlled by genes belonging to three allelic series Sg1, Sg2 and Sg3, located on chromosomes XVIII, IX and XIII, respectively. The Sg1 and Sg2 series appeared to have three alleles and the Sg3 series had two alleles; the alleles being Sg1, Sg1c and sg1, Sg2, Sg2c and sg2 and Sg3 and sg3 in order of dominance for each series.Genotypes of the eight varieties are proposed, namely, sg1 sg2 Sg3 for Elgin, Kharkov and Jones Fife, Sg1c Sg2c Sg3 for Chinese Spring, Sg1c Sg2 Sg3 for Red Egyptian, Sg1 Sg2c Sg3 for S-615 and Sg1 Sg2 sg3 for Prelude and Red Bobs.All winter varieties studied carried the typical winter habit genes, sg1 and sg2. The gene sg1 was much more effective than sg2 in delaying heading. Spring varieties carried some of the less effective spring habit genes, Sg1c, Sg2c or sg3 instead of the typical spring habit genes, Sg1, Sg2 or Sg3.Concerning awnedess, monosomic analysis revealed that awnlessness of Chinese Spring is ascribed to two inhibitors Hd and B2 on chromosomes VIII and X, respectively while that of Red Bobs to the presence of inhibitors B1 on chromosome IX and B2 and the absence of the a1 promotor on chromosome II; awnlettedness of Elgin and Jones Fife is controlled by the B1 gene; and awnedness of Prelude, Kharkov, S-615 and Red Egyptian is due to absence of all inhibitors. Conventional analysis confirmed the results obtained by monosomic analysis and indicated that an inhibitor on chromosome XVI of Chinese Spring affected F2 segregation of awnedness when crosses were made between Chinese Spring and other varieties.

SAWFLY RESISTANCE IN WHEAT: III. CHANGES IN RESISTANCE DURING THE DEVELOPMENT OF THE WHEAT PLANT

Quantitative data obtained in field experiments showed that the resistance of wheat to attack by the wheat stem sawfly (Cephus cinctus Nort.) depended on the stage of development of the plants at the time of oviposition. Wheat plants were usually most heavily infested for a part or all of the period from 1 week before shot blade to 1 week after the flowering stage. Rescue, H46146, H4191, Golden Ball, and Melanopus lost their resistance to the development of the eggs and first-instar larvae some time between shot blade and flowering. Thatcher and Red Bobs did not show this type of resistance. The mortality of the older larvae increased in plants infested toward maturity. The time at which this increase began depended on the variety involved and ranged from just before shot blade to just after flowering.

Monosomic and Conventional Analyses in Common wheat. III Lethality

Conventional and monosomic analyses of the lethality occurring in diallel crosses of eight common wheat varieties led to the following conclusions:(1) Lethality is controlled by two dominant complementary genes.(2) The gene in Prelude is located on chromsome V and designated as Le1.(3) The gene in Kharkov and Jones Fife is the same; it is located on chromsome XIII and designated as Le2.(4) Chinese Spring, S-615, Red Bobs, Elgin and Red Egyptian carry the recessive normal alleles of both genes.(5) The genetic penetration of the recessive normal gene is about 0.05%.The experimental results indicate that monosomic analysis, using an incomplete monosomic series, can be successfully applied when a few major genes are involved in the inheritance of a specific character.

SAWFLY RESISTANCE IN WHEAT: II. DIFFERENCES BETWEEN WHEAT GROWN IN THE GREENHOUSE AND ON IRRIGATED LAND

The resistance of seven varieties of wheat to the wheat stem sawfly (Cephus cinctus Nort.) was tested in the greenhouse and on irrigated plots. In five of the seven varieties tested, namely, Rescue, H46146, Golden Ball, Red Bobs and Thatcher, the percentage of infested stems that were cut by sawflies was significantly higher in plants grown in the greenhouse in either summer or winter than in plants grown under irrigation in the field. In the other two varieties, H4191 and Melanopus, results were similar but the differences were not significant. This lower resistance of plants grown in the greenhouse was associated with a decrease in the percentage of tunnelled stems in which the older larvae had died. In percentage of infested stems cut, no significant differences were found between the varieties grown in the outdoor soil bins and those on adjacent irrigated land. In other 2-year tests on irrigated land, the variable resistance of wheat was apparently associated with variations in percentage of tunnelled stems in which the older larvae had died. Although stem solidness is usually associated with resistance on dry land, it appears that this characteristic alone cannot be relied on as a measure of sawfly resistance in a given variety when grown in diverse environments.

THE ABSORPTION OF NUTRIENTS BY TWO VARIETIES OF WHEAT GROWN ON THE BLACK AND GRAY SOILS OF ALBERTA

Chemical analyses carried out at five stages of development of Reward and Red Bobs wheat grown on the black and the gray soils of Alberta showed that differences in soil and variety significantly influenced the composition of the plants.The weights of dry matter and all nutrients studied were higher for the black-soil plants.On the basis of percentage dry matter all nutrients, except phosphorus, were higher in the black-soil plants. Reward was higher than Red Bobs in nitrogen when grown on the black soil; and in ash, phosphorus and potassium when grown on the gray soil.The grain of gray-soil plants was higher in all ash constituents but lower in nitrogen. Varietal differences were more marked in the grain and straw of the mature plants, Reward grain grown on both soils being higher in nitrogen, ash, phosphorus and magnesium.The total weights, percentages, rates of absorption and ion ratios all indicated that nitrogen and sulphur were limiting the growth of wheat on the gray soil. It is suggested that the proportionately higher absorption of phosphorus from the soil was in compensation for the low availability of nitrogen and sulphur.The differences in original quality of the wheats grown on the two soils can be largely accounted for by the differences in protein content, and therefore nitrogen supply. Phosphorus absorption, nitrogen, phosphorus and sulphur balance, and the relation of ash to protein, are possibly important in determining the keeping properties of the flour.

STUDIES ON DROUGHT RESISTANCE IN SPRING WHEAT

The results of a number of preliminary investigations regarding the nature of drought resistance in wheat are presented.A study of the susceptibility of wheat plants to drought at different stages of development showed that the shooting and the soft-dough periods were the most critical, from the point of view of grain yield. Heavy foliage losses occurred when plants were exposed during the shooting period, and recovery was very slow. Exposure of plants during the stooling stage resulted generally in transient injury, as the capacity for recovery was particularly great at this time. Plants subjected to drought during the hard-dough stage sacrificed little in kernel plumpness.Hardening of wheat plants by soil drought, or by limited exposures to atmospheric drought, increased their resistance to exposures of severe atmospheric drought.The drought-resistant varieties Milturum and Caesium were found to possess a more highly branched primary root system than the non-resistant varieties Marquis and Reward. The durum varieties, Pentad and Pelissier, were found to excel in numbers of primary roots produced, having an average of five per plant. Milturum, Caesium and Baart had more than four primary roots per plant on the average; while Canus, Federation, Reward, Marquis, Garnet and Red Bobs No. 222 had from 3.2 to 3.6. Reliance wheat and wild oats had not more than three primary roots per plant.The addition of superphosphate to the soil resulted in a slight decrease in number of primary roots of Milturum, Caesium and Marquis, and a slight increase in the number of Reward.The kernels of the drought-resistant varieties, Milturum and Caesium, did not show any marked superiority to those of Marquis, Reward, Garnet and Red Bobs No. 222, in capacity to germinate in the more concentrated solutions of sodium chloride, potassium chloride and sucrose. A higher energy of germination was displayed by the kernels of Milturum, Caesium and Garnet than by those of the other three varieties tested.Milturum and Canus exhibited high resistance to injury from windburn when tested m the late stooling to early shooting growth stages. The durum varieties Pentad and Kubanka and the soft wheat, Baart, on the other hand, showed high susceptibility. The soft wheat, Federation, and the variety Red Bobs No. 222 were moderately susceptible.

EFFECT OF FROST ON WHEAT AT PROGRESSIVE STAGES OF MATURITY: I. PHYSICAL CHARACTERISTICS OF THE KERNELS

Samples of freshly cut wheat were exposed in freezing chambers, then stook-cured, threshed, and compared with unfrozen check samples, in the seasons 1929, 1930 and 1932, at Edmonton, Alberta. The check samples attained approximately maximum grade and weight per bushel when cut at a stage of maturity represented by a dry matter content ranging in different varieties and seasons from 50 to 60%. The weight per 1000 kernels of Marquis wheat, determined in 1930 only, reached a maximum at the same stage as weight per bushel. Susceptibility to superficial injury by frost continued generally over nearly the whole maturation period. Even 4 degrees of frost (28° F.) frequently caused a cut in grade, while 8, 10 and 14 degrees caused more substantial degradation, often accompanied by some reduction in weight per bushel. Marquis wheat is apparently more susceptible than Garnet, Reward and Red Bobs, to degradation by frost during the maturation period. Grade, being based on external appearance, is more sensitive to frost than are chemical composition and baking quality. Classification of the kernels of Marquis, in 1930, into vitreous, starchy, immature, green, bran frosted and heavily frosted, confirmed the earlier conclusion (2) that only the sound class (vitreous + starchy) has enough relation to grade to be useful as a grading factor. The germination of Garnet was improved by moderate freezing.

INHERITANCE OF BUNT AND LOOSE SMUT REACTION AND OF CERTAIN OTHER CHARACTERS IN KOTA × RED BOBS AND GARNET CROSSES

Genetic studies were made in F2, F3 and F4 on the progeny of two common wheat crosses, Kota × Red Bobs and Kota × Garnet. Two chlamydospore collections from pure line hosts were used for inoculation in the bunt studies. The heritable nature of bunt reaction was clearly demonstrated in these crosses and evidence obtained that the degree of resistance found in Garnet must be conditioned by a single major factor. No genie hypothesis could be offered to explain the findings in regard to loose smut reaction due to a lack of agreement in infection percentages in the F3 and F4. Red kernel color in Kota and Red Bobs was found to be governed by two factor pairs. The results on the inheritance of awn characters agreed with the earlier findings of Clark and other workers with crosses of similar awned types, several factor pairs being involved. Two main factors appeared to condition the difference in strength of straw between Kota and Garnet, but the entire expression of the character can best be explained on a multiple factor basis. Correlated inheritance studies, made with the use of the correlation ratio η, indicated the presence of two linkage groups concerned with reaction to the bunt forms used. However, the linkage apparent between strength of straw and bunt susceptibility factors and between awn type and bunt resistance factors is not considered to be close enough to interfere with breeding for desirable bunt resistant varieties.

THE RELATIVE MILLING AND BAKING QUALITY OF WESTERN CANADIAN SPRING WHEAT VARIETIES

To maintain the quality of Canada's export wheat it is essential that only high quality varieties should be grown. To supply information on which a choice of varieties may be based, a co-operative study was made of the milling and baking quality of 25 varieties of spring wheat now grown in western Canada. Samples were grown in adjacent plots by the Dominion Experimental Farms and Universities in Manitoba, Saskatchewan and Alberta in 1928, 1929 and 1930. Only samples which were sound enough to be placed in the statutory grades by official inspectors were used. Part of each sample was milled and baked in each of the three co-operating laboratories. Four baking formulas were used. The varieties were classified on the bases of loaf volume, texture, crumb color, general appearance of loaf, absorption, and yield of straight flour. These classifications were combined to give classifications for baking quality and milling quality and finally for suitability for export and domestic milling. The last classification is given in Table XXVII and is, briefly, as follows:1. Varieties which are entirely satisfactory: Reward, Ceres, Marquis, Pioneer, Red Fife, Renfrew, Red Bobs 222, Supreme.2. Varieties which are fairly satisfactory: Early Red Fife, Ruby, Early Triumph.3 Varieties which are unsatisfactory: (a) White wheats: Quality, Axminster, Hard Federation; (b) Varieties differing from Marquis in milling characteristics: Garnet, Kota; (c) Varieties inferior to Marquis in baking characteristics: Garnet Parker's Selection, Brownhead, Huron, Kitchener, Preston, Marquillo.4. Varieties which are very unsatisfactory: Early Prolific, Dicklow, Vermilion.