Red Bobs Research Articles

Spring bread wheat response to kernel smut pathogens (Tilletia caries and T. laevis) in the Republic of Tatarstan

Wheat kernel smut (KS) is a disease of the reproductive organs. With low-cost and organic farming, grain farmers can face significant losses from this disease. The purpose of the current study was to identify resistant samples to KS pathogens in the Republic of Tatarstan during artificial inoculation of seeds with smut spores. There have been studied the spring wheat varieties recommended for cultivation in the Republic of Tatarstan, almost isogenic lines of the Red Bobs variety carrying the known Bt-genes Bt 1–10 from the collection of the All-Russian Institute of Genetic Resources of Plants named after N.I. Vavilov. When analyzing the species structure of the KS population spread in Tatarstan for 9 years (2012–2020), it was found that the species Tilletia caries prevailed over T. levis and the ratio of species depended on the soil pH before sowing. The minimum ratio of the number of spores of T. laevis / T. caries species in the studied samples was noted at the soil pH of 4.5. The correlation coefficient between indicators of soil solution response and species ratio was 0.86 (tfact˃ttheor at 1% significance level). The genes Bt 2, Bt 5, Bt 8, Bt 9, Bt 10 were highly effective for the Tatarstan KS population in the period of 2018–2021. The samples ‘M83-1621’ (cat. VIR 66238) of the USA and ‘AC Cadillac’ (cat. VIR 64565) of Canada carrying the Bt 10 gene had no signs of the disease. Most of the varieties recommended for cultivation (65%) are highly and very strongly susceptible to KS. Three varieties ‘Chernozemnouralskaya 2’, ‘Sitara’ and ‘Burlak’ are found weakly susceptible to KS.

Genetic Loci Conditioning Adult Plant Resistance to the Ug99 Race Group and Seedling Resistance to Races TRTTF and TTTTF of the Stem Rust Pathogen in Wheat Landrace CItr 15026.

Wheat landrace CItr 15026 previously showed adult plant resistance (APR) to the Ug99 stem rust race group in Kenya and seedling resistance to Puccinia graminis f. sp. tritici races QFCSC, TTTTF, and TRTTF. CItr 15026 was crossed to susceptible accessions LMPG-6 and Red Bobs, and 180 double haploid (DH) lines and 140 recombinant inbred lines (RIL), respectively, were developed. The 90K wheat iSelect single-nucleotide polymorphism platform was used to genotype the parents and populations. Parents and 180 DH lines were evaluated in the field in Kenya for three seasons. A major quantitative trait locus (QTL) for APR was consistently detected on chromosome arm 6AS. This QTL was further detected in the RIL population screened in Kenya for one season. Parents, F1, and the two populations were tested as seedlings against races TRTTF and TTTTF. In addition, the DH population was tested against race QFCSC. Goodness-of-fit tests indicated that the TRTTF resistance in CItr 15026 was controlled by two complementary genes whereas the TTTTF and QFCSC resistance was conditioned by one dominant gene. The TRTTF resistance loci mapped to chromosome arms 6AS and 6DS, whereas the TTTTF and QFCSC resistance locus mapped to the same region on 6DS as the TRTTF resistance. The APR identified in CItr 15026 should be useful in developing cultivars with durable stem rust resistance.

Evaluation of Heirloom and Commercial Cultivars of Small Grains under Low Input Organic Systems

A cultivar trial, including commercial and heirloom cultivars of major cereals and grain legumes was conducted in Vancouver, BC, under low input organic conditions. We assessed 19 wheat (6 commercial and 13 heirloom), 17 barley (8 commercial and 9 heirloom), 5 pea, 5 favabean, 5 kidneybean, 2 lentil, and 2 soyabean cultivars for plant performance metrics, and their potential in a small grain:legume intercropping system. Heirloom wheat cultivars showed notable response in a number of parameters including late maturity, taller plants, greatest number of spikes per m2, longest spike, highest number of seed per spike, greater seed weight to volume ratio, and resistance to stripe rust compared with commercial cultivars. For the heirloom-type, 6 of 14 wheat cultivars, (i.e., “Reward”, “Glenn”, “Cerebs”, “Red Bobs”, “Sounders” and “Black Bearded”) produced yields comparable to the commercial cultivars (i.e., nearly 5 t/h or higher). Also, heirloom cultivars typically contained higher protein levels most suitable for baking and blending purposes with “Einkorn” displaying the highest level (16.2%). Heirloom and commercial barley cultivars did not differ significantly with respect to plant height, spike length, and seed weight to volume ratio. However, a number of heirloom cultivars (e.g., “Jet”, “Dolma”, “Andie” and “Himalayan”) displayed greater responses on earliness, number of spikes per m2, grain yield, protein content and seed weight to volume ratio. Pea and lentil yielded lower than the national average under trial conditions. However, heirloom peas “Corgi”, “De Grace”, “Snowbird”, and “Golden” were earlier compared to the commercial cultivar “Reward”. All kidney bean cultivars yielded ~3 t/h with the highest yield from “Red Kidney” (3.8 t/h). Fava and soyabean appeared as promising crops as the cultivars produced good growth and yields. Neither lentil (“Crimson” and “Essex”) produced satisfactory responses though they had excellent vegetative growth and flowered. Therefore, significant variation was observed including several heirloom cultivars displayed great potential in terms of yield, protein content, and disease resistance and that specific cultivars were better suited for an intercropping system.

Culm height and susceptibility of Canadian winter and spring wheat cultivars to common bunt (Tilletia tritici and T. laevis)

A field study involving winter and spring wheat cultivars possessing race-specific and nonspecific resistance to Tilletia tritici and T. laevis was conducted to determine the effect of bunt on culm dwarfing, and the role of culm height in the susceptibility of wheat cultivars. Bunt-induced stunting, ranging from 2.4 to 21%, was observed in 20 of 25 cultivars and the severity was correlated with level of bunt (r = 0.86). Also, there was preferential infection of shorter culms by the bunt fungus and this appeared to be a major factor in the susceptibility of most cultivars in this study. Cultivars possessing moderate to high levels of nonspecific resistance such as Katepwa and Chinook had fewer short culms; these short culms were susceptible. A large proportion of the culms of short-statured or semi-dwarf cultivars such as HY320, Tobari 66, and the soft white spring wheats Fielder and Springfield, fell into the shortest height classes; uniformly these were highly susceptible to bunt infection. Laura and Roblin, cultivars of conventional height, had a large proportion of short culms and these were highly susceptible. Red Bobs 222 and HY355 also exhibited high levels of bunt in the taller culms. Cultivars possessing race-specific resistance such as the durum wheats and BW553 had low levels of infection across the culm height classes. Cultivar variation in susceptibility to bunt within each of the different culm height classes also was observed. The possible implications of the effect of preferential bunting of short culms on development in short-statured or semi-dwarf wheats are discussed. Key words: Stinking smut, Norin 10/Brevor

Intervarietal differentiation of the nucleolar chromosomes in wheat (Triticum aestivum L.).

Chromosomes 1A, 1B, 6B and 5D have been found to be satellited in all the four bread wheat varieties studied. These chromosomes have been found to be quite differentiated from one another in length and morphology. Chromosome 6B was unique amongst them in having a tertiary constriction in its long arm. Chromosome 5D was also quite distinct in having a satellite at right angle curve at MI.The four varieties Cadet, Sonora 64, Red Bobs and S-615 have shown considerable variation in length and some in morphology of the chromosomes at MI and AII. In general, Cadet has been found to have the longest chromosomes and Sonora 64 the smallest. The varieties Red Bobs and S-615 come intermediate between them.

Heterokaryon formation in planta by genetically marked strains of Tilletia caries

Genetically marked and wild-type haploid cultures of Tilletia caries were mixed and used as inocula to analyze their potential for heterokaryon formation in the susceptible spring wheat variety 'Red Bobs' (Triticum aestivum L.). Of the fungus-treated plants inoculated by hypodermic needle injection into the boot at the flag leaf stage, 30 to 64% proceeded to maturity; the remainder failed to head. Tilletia caries was recovered from each of 38 representative plants which failed to head and from 3 plants which headed but showed no visible signs of infection. None of the inoculations resulted in teliospore formation within mature heads or other plant tissues. Genetic analysis of hyphal fragments obtained from mycelium in infected plants indicated that a heterokaryon had formed in each of two pairings of different auxotrophic strains of the fungus. The number of nuclei present in hyphal cells was variable. However, secondary sporidia derived from the heterokaryon were mononucleate with one exception and exhibited the nutritional requirement of one or the other parental strain. Results are discussed in relation to the development of a system for mitotic and meiotic analysis of single gene traits in the bunt fungi.

Inheritance of virulence of Ustilago tritici on the differential cultivars Carma, Red Bobs, and a derivative of the cross Thatcher × Regent

A cross between races T2 and T5 of Ustilago tritici was used to study the inheritance of virulence on three differential cultivars of spring wheat: Carma, Red Bobs, and a derivative of the cross Thatcher × Regent. Virulence on each of the cultivars was conditioned by a recessive gene. Gene Utv3 is responsible for virulence on cv. Carma, Utv4 for that on cv. Thatcher × cv. Regent, and virulence on cv. Red Bobs appears to be conditioned by the previously identified gene Utv1. These genes segregate independently from each other and from the gene for mating type.

INHERITANCE OF SEED COAT COLOR IN EIGHT SPRING WHEAT CULTIVARS

Segregation for seed coat color was studied in F2 populations of crosses between eight red-seeded and three white-seeded cultivars of spring wheat (Triticum aestivum L. em Thell). Red Bobs and Pitic 62 each possessed a single gene for red seed coat color; Glenlea and NB320 each carried two genes; Neepawa, Park and RL4137 each possessed three genes. Data for crosses with Manitou were not sufficient to distinguish between the presence of two or three genes for seed coat color in this cultivar.

THE EFFECT OF THE WHEAT STEM SAWFLY, CEPHUS CINCTUS (HYMENOPTERA: CEPHIDAE), ON THE YIELD AND QUALITY OF WHEAT

AbstractLarvae of the wheat stem sawfly, Cephas cinctus Nort, reduced the weight of grain per head by an average of 17.3% in the two spring wheats Red Bobs and Thatcher with annual reductions varying from 10.8% to 22.3%. They also lowered the protein content in Thatcher by an average of 0.6% and a maximum of 1.2%. However, because a significant loss in protein content occurred in only 1 of 6 years in Red Bobs, the effects of the larvae on protein content cannot be generalized for all varieties.The losses in weight per head resulted from a mean reduction of 11.9% in the weight of the kernels combined with a mean reduction of 1.9 in the number of kernels per head. The larvae caused the losses by feeding in the stems and by cutting them when the moisture contents of the kernels were relatively high. Annual variations in losses were attributed to the dates of the infestation, to the amount of precipitation in July and August, and to differences in dates of cutting by the larvae.

INHERITANCE OF VIRULENCE IN PUCCINIA RECONDITA ON ALLELES AT THE Lr2 LOCUS FOR RESISTANCE IN WHEAT

The inheritance of virulence on the Lr2 alleles for resistance to the leaf rust fungus (P. recondita Rob. ex. Desm.) was investigated using selfed and "backcross" selfed cultures of race 11, F1 cultures of race 9 × race 11, race 11 × race 161 and F1 and F2 cultures of race 9 × race 161. The three host alleles Lr2a, Lr2b and Lr2c were transferred into the wheat varieties Thatcher, Red Bobs and Prelude by a series of backcrosses. Race 11, and probably race 161, have a single recessive gene, p2, for virulence on the three Lr2 alleles and an additional gene(s) that modifies or inhibits the action of the p2 gene on the three host alleles. Lines with the Lr2a gene from Webster were most resistant to the greatest number of cultures, those with Lr2b from Carina were intermediate while those with Lr2c from Brevit and Loros were least resistant. The Lr2 alleles were most effective in the Thatcher background, intermediate in Prelude and least effective in Red Bobs.

Location of Genes for Seed Coat Color in Hexaploid Wheat, Triticum aestivum L.1

Monosomic analysis was used to ascertain that red seed coat color in ‘Red Bobs’ wheat (Triticum aestivum L.) is controlled by one gene located on chromosome 3A. A second factor, tentatively located on chromosome 3B, and a third gene located on 3D governed seed coat color in ‘Kharkof’ wheat. One of the three genes that control seed coat color in PI 178383 wheat was associated with chromosome 3B. The gene located on chromosome 3B in Kharkof and PI 178383 was designated R3.

GENETICS OF STEM RUST RESISTANCE IN THE WHEAT CULTIVAR RED BOBS

The inheritance of resistance to stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. and E. Henn.) was investigated in Triticum aestivum L. cv. Red Bobs. It carries a gene for stem rust resistance at the Sr7 locus that resembles Sr7b of Marquis, and a gene that is either Sr10 or, more likely, an allele, because Red Bobs is less resistant than the Marquis-Sr10 line to races C1 (17) and C17 (56).

Changes in lipids of cereal seedlings during vernalization.

Noticeable changes in lipids were observed during growth of Sangaste fall rye, Prolific spring rye, Kharkov winter wheat, and Red Bobs spring wheat, at vernalizing temperature, over a period of 6 weeks. There was, however, little difference between the trends exhibited by the four varieties, apart from the fact that the rye varieties apparently accumulated more linolenic acid than the wheat varieties whereas the reverse was true for linoleic acid. These results suggested that the lipids under study did not play a direct role in the vernalization response, and the changes observed were a result of low-temperature growth.

GENETICS OF RESISTANCE TO LEAF RUST IN THE COMMON WHEAT VARIETIES WEBSTER, LOROS, BREVIT, CARINA, MALAKOF AND CENTENARIO

Inheritance of seedling resistance to races 15 and 161 of leaf rust was investigated in the varieties Webster, Loros, Brevit, Carina, Malakof and Centenario. Backcross lines were developed in Thatcher and/or Prelude with leaf rust resistance derived from all the varieties except Brevit. The varieties and backcross lines were tested with nine races of rust. Webster was found to have the Lr2 gene which accounts for all of its resistance to the races used. Carina has an allele, Lr22, at the Lr2 locus, plus a gene tentatively assigned the symbol LrB, independent of the Lr2 locus which confers a type 2 reaction to races 15, 161 and probably several others. Resistance present in Loros is accounted for another allele, Lr24, at the Lr2 locus. Brevit also has an allele at the Lr2 locus which may be the same as that in Loros. In addition it probably has gene LrB conferring a type 2 reaction. Gene Lr1, which was independent of the Lr2 locus, accounts for all the detected resistance in Malakof. Centenario has the Lr1 gene and in addition has resistance to races 5 and 126a.The susceptible parents Thatcher and Prelude influence the dominance of the Lr2 alleles. The Lr22 allele in Carina x Prelude6 was partially dominant in crosses with Thatcher and completely dominant in crosses with Red Bobs. The Lr24 allele in Loros x Prelude6 was recessive in crosses with Thatcher and completely dominant in crosses with Prelude and Red Bobs.The expression of resistance of the Lr2 alleles to race 161 in Webster and Carina was different in crosses with Red Bobs than in those with Thatcher. In the crosses with Red Bobs one or more genes, which modified the degree of resistance to race 161, appeared to be segregating. This was not observed in crosses with Thatcher.

REPRODUCTIVE POTENTIALS OF RACES 15B AND 56 OF WHEAT STEM RUST

Variations in the prevalence of races 56 and 15B-1 (Can.) of wheat stem rust (Puccinia graminis Pers. f. sp. tritici Erikss. and Henn.) have occurred that cannot be explained by changes in the wheat varieties grown in Western Canada. The reasons for the changes in prevalence were investigated by comparing in growth cabinets the reproductive potentials or aggressiveness of the two races and the factors that might influence them. When a mixture of urediospores of the two races was used to inoculate three susceptible varieties for successive uredial generations, race 56 predominated at 25 and 20 °C, and race 15B-1 (Can.) predominated at 15 °C. Experimentation showed that the urediospores of race 56 were more infective than those of 15B-1 (Can.) and that the incubation period of race 56 was shorter than that of race 15B-1 (Can.). Pustules of race 56 grew faster than those of race 15B-1 (Can.) during early stages of development but those of 15B-1 (Can.) ultimately became larger than those of race 56. Race 56 produced more urediospores per pustule than race 15B-1 (Can.) on the susceptible varieties Little Club, Red Bobs, and Marquis at 15 and 20 °C. Infection density markedly affected competitive abilities. Race 56 tended to predominate in light infections but race 15B-1 (Can.) tended to predominate in heavy infections. Pustule size decreased as infection density increased. The possible significance of these findings under field conditions is discussed. It seems likely that the rise of race 15B-1 (Can.) to predominance in 1950 resulted not only from the selection pressure of the widely grown varieties that were resistant to race 56 and susceptible to 15B-1 (Can.) but from the lower temperatures that prevailed and favored 15B-1 (Can.) over 56. The rise to predominance of race 56 from 1956 to 1961 may have resulted from the greater aggressiveness of that race under the moderate or warm conditions that prevailed.

Sulfhydryl and Disulfide Patterns Associated with Vernalization of Wheat

AbstractAnalyses of plumules from seedlings of a winter wheat variety (Elgin) and a spring wheat variety (Red Bobs) indicated that SH and SS contents based on protein levels were similar in the whiter and spring wheat tissues grown at 20 C. Boll) varieties, when grown nt 3 C, contained greater concentrations of SH and SS groups, based on protein levels, than those present in the tissues grown at 20 C. The spring wheat tissues at 3 C maintained relatively constant levels of SH and SS during the growth period.Sulfhydryl (SH) and SS groups based on fresh weights were present in greater quantities in the tissues of the spring wheat grown at 20 C than in the winter wheat tissues grown at 20 C. The high SH and SS concentrations present in the warm‐grown spring wheat tissues were due to a high concentration of protein extracted from that tissue. The SH and SS contents per unit fresh weight were quite similar in the cold‐grown tissues of both varieties during the growth period. Both varieties at both temperatures showed a similar decrease in SH and SS contents, based on fresh weights, as maturation progressed.The spring wheats grown at 3 C and 20 C and the winter wheat grown at 3 C all showed similar characteristics and differed considerably from the winter wheat grown at 20 C. These data were positively correlated with the flowering potential of the wheat varieties.

INHERITANCE OF SAWFLY REACTION AND STEM SOLIDNESS IN SPRING WHEAT CROSSES: STEM SOLIDNESS

Inheritance of stem solidness was studied in populations of F3 and B2 lines from the Red Bobs × C.T. 715 and Redman × S-615 (Triticum aestivum L.) crosses and backcrosses. The data supported the hypothesis that the varieties in each cross differed by four genes for stem solidness. In both crosses, one gene exerted a major influence in that its allele for hollowness in the homozygous condition was epistatic to the other three genes. The other three genes within each cross were similar in their influence on solidness. Between the two crosses, corresponding genes differed in some degree.Genetic analyses and correlation coefficients both revealed a close association between sawfly resistance and stem solidness in the Red Bobs × C.T. 715 cross indicating that the stem solidness character was largely responsible for conditioning the degree of sawfly reaction in a plant.In both crosses, a weak negative correlation was found between stem solidness and height. Stem solidness was not associated with bunt (race T-2) reaction, glume color, awn type, or heading date.

INHERITANCE OF SAWFLY REACTION AND STEM SOLIDNESS IN SPRING WHEAT CROSSES: SAWFLY REACTION

Inheritance of reaction to the wheat stem sawfly, Cephus cinctus Nort., was studied in populations of F3 and B2 lines from the cross Red Bobs × C.T. 715 (Triticum aestivum L.), and the respective backcrosses. The data supported the hypothesis that the varieties differed by three genes for sawfly reaction. A major influence was attributable to one gene. Its allele for susceptibility when homozygous was epistatic to the other two genes. Its allele for resistance was twice as effective as either of the other genes in conditioning resistance. The other two genes lacked dominance and were equal in their influence on sawfly reaction.Correlation coefficients showed that sawfly reaction was not associated with reaction to race T-2 of Tilletia caries (DC.) Tul., heading date, or awnedness. Sawfly susceptibility was weakly correlated with height.

AN UNUSUAL TRANSMISSION RATE OF THE DEFICIENT MALE GAMETE IN A SUBSTITUTION MONOSOMIC OF CHROMOSOME 3D IN WHEAT

An unusual segregation of disomics, monosomics, and nullisomies (11, 38, and 51%, respectively, in summer and 11, 50, and 39%, respectively, in fall) was observed in the offspring of a substitution monosomic of chromosome 3D from Red Bobs into a hybrid of Rescue (Triticum aestivum L. emend Thell.) and Golden Ball (T. durum Desf.).Pollen with 20 and 21 chromosomes occurred in the frequency of 64 and 36%, respectively.The deficient male gametes effected fertilization in a frequency of 61%, that is, about the same frequency in which they occur, with two female parents, and in a frequency of 31% with two others, thereby showing the effect of stylar parent on the transmission of male gametes. The deficient female gametes are transmitted in a frequency of 76%. The 61% transmission of the deficiency on the male side and 76% on the female explain the unusual segregation in the summer crop.Monosomic plants selfed in the summer produced more nullisomics and fewer monosomics in their progeny than monosomics selfed in fall. The lower rate of functioning of the deficient male gamete in fall (about 51%) has been assumed to cause this difference.

COMPARATIVE GROWTH AND FUNCTION OF NORMAL AND DEFICIENT POLLEN IN A SUBSTITUTION MONOSOMIC OF CHROMOSOME 3D IN WHEAT

Normal pollen with chromosome 3D from Red Bobs had little competitive advantage over pollen deficient for chromosome 3D when a substituted monosomic line of wheat derived from the hybrid Rescue × Golden Ball was selfed. Although the initial rate of pollen tube growth of the 21-chromosome pollen was greater than that of the 20-chromosome pollen, ultimately the two kinds of pollen functioned in the proportions in which they were formed. The 21-chromosome pollen of the substitution monosomic had an advantage over 20-chromosome pollen in a cross with monosomic 3D of Red Bobs, but not with three other 3D monosomic varieties. However, normal pollen in all the reciprocal crosses showed a competitive advantage, affecting fertilization in up to approximately 90% of the cases. Thus chromosome 3D in the Rescue – Golden Ball medium gives the normal pollen little competitive advantage.