Rye Parents Research Articles

The influence of wheat–rye parental species on the protein characteristics of primary triticale

The influence of parental tetraploid wheats (Triticum turgidum L.) and diploid ryes (Secale cereale L.) of predetermined protein content on the protein characteristics of derived hexaploid (2n = 6x = 42) triticale amphidiploids (× Triticosecale Wittmack) was investigated. Although the two parental species contributed independently to the protein content of the derived triticale. the maternal wheat parent had a greater influence than did the rye parent. Thus, triticales derived from combinations of wheat × rye of "high × high" protein content were themselves of high protein content, followed in descending order of protein by "high × low," "low × high." and "low × low" combinations. The difference in protein content of triticales derived from the reciprocal combinations of the wheat–rye protein groups (i.e., high × low versus low × high) was significant. Polyacrylamide gel electrophoretic analyses of extracted prolamine from the triticale amphidiploids and their parents revealed that polymorphism can exist in the protein banding patterns of any given population. As expected, the degree of polymorphism was greatest in those triticale populations synthesized from open-pollinated heterozygous rye strains, but polymorphism was also seen within some amphidiploid populations derived from inbred (S6–S8) parental ryes. For purposes of biological studies, it is important to recognize the genetic heterogeneity that can still exist within populations of plant species and their hybrids assumed to be genetically and chromosomally stable.Key words: × Triticosecale Wittmack, protein electrophoresis, wheat–rye hybrids, amphidiploids.

Cytogenetics of the trigeneric hybrid, (Hordeum vulgare ×Triticum aestivum) ×Secale cereale

Chromosome pairing was studied in hybrids of (Hordeum vulgare ×Triticum aestivum) ×Secale cereale. Chiasma frequency per cell varied from 1.94 to 3.16 between the different hybrids. This variation was attributed to genetic variability in rye parents which affected homoeologous pairing. The pairing of rye chromosomes as revealed by Giemsa C-banding was a combination of nonhomologous association between rye chromosomes and associations with chromosomes of wheat and barley.

PARENTAL EFFECTS ON CHROMOSOME DOUBLING FOR THE PRODUCTION OF PRIMARY TRITICALE

Intergeneric hybridization between six hexaploid wheat (Triticum aestivum L.) cultivars and five inbred rye (Secale cereale L.) lines was used to study the influence of parental genotypes upon chromosome doubling after colchicine treatment. Significant differences were attributed to independent effects of the wheat and rye parents. Self-fertility of the derived amphidiploids was positively correlated with colchicine responsiveness.

Absorption of copper by wheat, rye and some hybrid genotypes

Abstract The physiological basis of genotypic differences in efficiency of absorption of copper from soils deficient in that element was investigated using short term uptake studies with 64Cu. Seedlings were grown in complete nutrient solutions (about one‐tenth Hoagland solution) at 18°C under high‐pressure sodium vapour lamps until 12 days old when 64Cu was introduced to the culture medium. After a one‐hour absorption time, the plants were desorbed in cold 0.05 mM CaSO4 before counting. The rate of absorption of copper from solutions of 0.01 μM Cu was slightly higher for ryes than for wheats, with triticales intermediate. This proved to be the general pattern regardless of whether uptake was expressed on the basis of root fresh weight, surface area or volume. However, important changes in the ranking did occur and it proved to be difficult to find a reasonable basis on which to compare genotypes. The higher efficiency of rye in extracting copper from copper‐deficient soils may lie in its root system geometry. At 12 and 21 days, despite a lower weight of roots, rye had a greater root length than wheat, brought about primarily by smaller diameter of both main axes and lateral roots and a higher branching rate of first order lateral roots. In these characters triticale was generally in an intermediate position. Rye also translocated more copper from roots to shoot under the same conditions. The greater copper efficiency of rye compared to wheat appears to depend on a number of properties of its root system, and perhaps of the shoot as well; triticale appears to be intermediate in expression of these characters from its rye parent.

MEIOTIC REGULATION IN TRITICALE: INTERACTION OF THE RYE GENOTYPE AND SPECIFIC WHEAT CHROMOSOMES ON MEIOTIC PAIRING IN THE HYBRID

The influence of parental genotype on the chromosomal pairing relationships within the wheat and rye genomes of triticale (× Triticosecale Wittmack) was investigated. Nullisomic 3A/tetrasomic 3B and nullisomic 5B/tetrasomic 5D plants of the cultivar Chinese Sping wheat were pollinated with inbred strains of rye (Secale cereale L.), the latter being selected on the basis of their average chiasma frequency. The level of chiasma number in the F1 hybrids was found to be influenced by the genotype of both the wheat and rye parents. Homeologous pairing was increased in the wheat × rye hybrids produced from inbred rye parents that exhibited high chiasma frequencies. However, this relationship was modified depending upon the genotype of the wheat parent. Increased dosage of chromosome 3B of wheat was found to increase chiasma frequency. These findings suggest that the genetic constitution of a rye parent and its specific combining ability with a certain wheat genotype markedly affects meiotic behavior of triticale.

The sensitivity of hexaploid and octoploid triticales and their parent species to copper deficiency

The tolerance of two triticales to soil of low copper status was determined in deep pots in a glasshouse experiment, and compared with the tolerance of their wheat and rye parent types. Both tetraploid and hexaploid wheats were extremely sensitive to copper deficiency, producing no grain without copper added to the soil. In contrast, rye and the hexaploid triticale were completely tolerant of the copper-deficient soil, producing as much grain without added copper as at the highest rate of copper supply. The octoploid triticale produced about 60% of maximum grain yield in the unamended soil, a performance intermediate between its rye and hexaploid-wheat parents. The cause of grain failure in the wheats was pollen sterility induced by copper deficiency, and this was related to low uptake of copper into the shoot and heads of wheat from the unamended soil. The pattern of uptake of zinc was quite different from that of copper in these plants, which suggests that a specific uptake mechanism for copper exists in rye which is genetically controlled and transferable to triticale, its hybrid with wheat. The copper efficiency so conferred on triticale would appear to be adequate for most field situations where copper deficiency exists.

Influence of parental rye on the development of embryos and endosperm of wheat–rye hybrids

Seven lines of rye (Secale cereale L.), six inbred (S9) and one open-pollinated, were used as pollen parents in crosses with two tetraploid wheat strains (Triticum turgidum var. durum cvs. 'Jori' and 'Langdon'). The rye lines were of diverse genetic background and exhibited significant differences in meiotic stability as measured by frequencies of chiasmata and univalent formation. The rate and extent of development of the embryo and endosperm tissue of hybrid ovules were not influenced by the level of meiotic stability of the rye parent, but rather by a genetic interaction between a specific rye genotype and wheat. This was indicated by the significant differences obtained in the frequency of normal embryo formation when different rye lines were used as parents in crosses to a common wheat cultivar. The specific effect of the wheat genotype on the mean seedset was shown by the significant differences obtained when different wheat cultivars were crossed with a given set of rye genotypes under the same environmental conditions. The prevailing ambient temperature significantly affected hybrid embryo and endosperm development in vivo.

Endosperm abnormalities in Triticum–Secale combinations. I. × Triticosecale and its parental species

The development of the fertilized embryo sac was investigated in four triticale lines, common wheat, durum wheat, and rye to ascertain whether a relationship exists between events taking place during the first 6–7 days of its life and kernel shrivelling. No differences were found with respect to embryo development either among triticale or between triticale and wheat lines. Generalized antipodal disintegration occurred earlier in rye and triticale with shrivelled seeds than in either wheat (common and durum) or triticale with full seeds; the difference was more pronounced between wheat and rye than among triticale lines. Triticale with shrivelled seeds and rye were also characterized by a higher number of aberrant endosperm nuclei and delayed generalized endosperm cellularization when compared with lines with plump kernels or with the wheats. No relationship could be established between the kind and position of aberrant nuclei and kernel shrivelling or frequency of aberrants and fertility. The rye parent is most likely responsible for the early degeneration of the antipodals, the formation of the aberrant endosperm nuclei, and the kernel shrivelling observed in triticale.

AMINO ACID COMPOSITION OF MATURING ENDOSPERM FROM HEXAPLOID TRITICALE AND ITS SPRING RYE AND DURUM WHEAT PARENTS

The amino acid composition of the maturing endosperm of a triticale (X Triticosecale Wittmack) designated line 6A190 and its rye (Secale cereale L.) and durum wheat (Triticum durum Desf.) parents were determined. In all three cereals, rapid changes occurred during development in the free amino acid levels and in the nature of the endosperm proteins. The composition of the free amino acids of triticale more closely resembled the rye parent than the durum wheat parent throughout endosperm development. The amino acid composition of the proteins and peptides of triticale was intermediate to the rye and durum wheat parents at all stages of development.

THE INHERITANCE OF RESISTANCE TO PUCCINIA RECONDITA IN HEXAPLOID TRITICALE

Rob. ex. Desm. f. sp. tritici, was studied in the hexaploid triticale cultivars 6A-190, Rosner, Armadillo, Bronco, and Toluca 160.Resistance in the triticales studied was monogenically inherited and each cultivar carried a single dominant gene. The genes conditioned resistance to races 15 and 30, and were designated genes A (6A-190), B (Rosner) C (Armadillo), D (Bronco), and E (Toluca 160). Gene A was linked in repulsion with gene C with a crossover value of 44.75 ± 1.44% and segregated independently from the other genes. Genes B and C were also independently inherited. Gene B was not linked with genes C, D, and E but observed distorted ratios with genes D and E suggested the presence of a modifying gene or genes. A similar distorted ratio was observed between genes C and D. Gene C assorted independently from gene E. No recombinants were recovered from the cross between Bronco × Toluca 160 suggesting that genes D and E were allelic or closely linked. The parental triticale cultivars Bronco and Toluca 160 carrying the genes D and E, respectively, appeared to carry modifying genes which inhibited the expression of resistance in certain crosses.The result obtained indicated that the genes governing resistance were derived from the tetraploid wheat parental species and that resistance to wheat leaf rust carried by the rye parent was not expressed in the triticale amphiploid. It was also found that genes conditioning resistance to wheat leaf rust were equally effective in conditioning resistance to rye leaf rust.

Triticale, a Man-Made Species of a Crop Plant

Triticale is a man-made crop resulting from a cross between wheat (Triticum) and rye (Secale). The name is derived from a combination of two scientific names. In the past wheat-rye hybrids probably have occurred many times where wheat and rye were growing together. Natural hybrids, which generally are sterile, still occur. Wilson (1875) in England probably reported the first successful man-made cross between wheat and rye, but the hybrid was sterile. Rimpau (1891) in Germarly obtained a fertile type Triticale. Btlt it wasn't till the technique of determining plant chromosome number was perfected that the fertile types were recognized as amphiploids, i.e. Triticale contained the somatic number of chromosomes of the wheat and rye parents. The Triticale strains with 56 chromosomes (42 from wheat and 14 from rye) are referred to as octoploid (8 X ) Triticale. Wheat-rye material tracing back to that of Meister (1921 ) who began working with Triticales in Russia, is still being grown experimentally in Kansas.

NATURE OF PROTEINS IN TRITICALE AND ITS PARENTAL SPECIES: I. SOLUBILITY CHARACTERISTICS AND AMINO ACID COMPOSITION OF ENDOSPERM PROTEINS

Solubility characteristics and amino acid composition of the endosperm proteins of one line of Triticale, its durum wheat and rye parent cultivars, and one cultivar of hard red spring wheat were compared. Quantitative distribution of the soluble protein fractions and amino acid compositions showed that the proteins of Triticale are intermediate in these properties between analogous properties of the proteins of its durum wheat and rye parents. The major differences between the hard red spring wheat and the other three species were its lower content of water-soluble proteins and higher content of insoluble or gluten proteins. This appears lo be the main reason for the superior breadmaking quality of the hard red spring wheat cultivar compared with the other species used in this study.

NATURE OF PROTEINS IN TRITICALE AND ITS PARENTAL SPECIES: III. A COMPARISON OF THEIR ELECTROPHORETIC PATTERNS

Comparison of the disc electrophoretic patterns for the albumins, globulins, gliadins, and glutenins of one line of Triticale and its durum wheat and rye parents showed that all the protein components of the interspecific hybrid are present in the parents. It is concluded that the proteins of Triticale are simply inherited from its parents. The patterns for the albumin and globulin groups for the cultivar of durum wheal (Stewart 63) and the cultivar of hard red spring wheat (Manitou) investigated were identical. Differences were observed in the patterns for the gliadins and glutenins of these two wheats. These qualitative differences might account for the difference in their breadmaking qualities, and provide additional evidence in support of the hypothesis that the genes for breadmaking quality factors are in the D genome.

Greenbug Resistance in Rye12

Twenty varieties of rye, Secale cereale L. exhibited a wide range (0—48%) of seedling survival following infestation with Schizaphis graminum (Rondani). The percentage of resistant plants among different seed sources of the same variety usually varied greatly except for ‘Caribou.’ Recurrent selection within Caribou increased its resistance from 39% to 96%. Resistance to the B biotype of greenbugs in Caribou appeared to be inherited as a single dominant gene. Wheat X Caribou Selection F1 plants were as resistant as their rye parents.

A thin-layer chromatographic study of the phenolics of Triticale and its parental species

The phenolics of young leaves from a hexaploid and three octaploid Triticale lines, and their rye and wheat parents were investigated by two dimensional thin-layer chromatography. Matching coefficients, coefficients of similarity, biochemical distances, and correlation coefficients were calculated to determine the degree of similarity of phenolics between the different groups. Chromatographic patterns and the calculated similarity measures showed a close relationship of phenolics between Triticale and its wheat parent. These patterns were even more closely related if the wheat parent was hexaploid. Two wheat varieties (Prelude and Kharkov) had identical chromatographic patterns while the variety Chinese Spring showed a reduced number of spots. The pattern of Stewart, a durum wheat variety, was intermediate between Chinese Spring and Prelude or Kharkov. Generally, the number of flavonoid compounds increased with the level of ploidy but did not increase proportionally with the number of genomes.

Intergeneric Hybrids between Allohexaploid (Hordeum depressum x H. compressum) and Autotertraploid Svalof Rye (Secale cereale)

A partially fertile pentaploid hybrid has been obtained from a cross between allohexapolid (Hordeum depressum x H. compressum) and autotetraploid Svalof rye (Secale cereale). The F1 hybrid was intermediate between the parents in most morphological characteristics with the BC1 plants more closely resembling the rye parent. Cytological observations through various chromosome associations indicated that some homology existed between the chromosomes of the two parents.

The comparison of wheat-rye and wheat-Aegilopsamphidiploids

1. The diploid speciesSecale cereale(2n= 14) is self-incompatible,Aegilops longissima(2n= 14) andA. caudata(2n= 14) are self-compatible.A. longissitnais usually self-pollinated andA. caudatais usually out-pollinated.2. Meiotic behaviour, constancy of chromosome number and seed fertility have been examined in the three octoploid amphidiploids derived from crosses ofTriticum vulgarevariety Holdfast (2n= 42) withS. cereale A. longissimaandA. caudatarespectively.3. All the amphidiploids had cells in which some chromosomes were unpaired at first metaphase of meiosis. This meiotic irregularity is not, therefore, related to the breeding system of the diploid parent.4. The fertility of the amphidiploids was not related to their meiotic regularity.5. The least fertile amphidiploid was derived from the self-incompatible diploidS. cereale. The most fertile amphidiploid was derived from the selfcompatible, self-pollinating diploid,A. longissima.6. It is suggested that the infertility of the wheatrye amphidiploid may result from interactions between genotypes adapted to different breeding systems, rather than from the homozygosity in the amphidiploid of deleterious recessive genes derived from the outbreeding rye parent.7. The demonstration of the independence of meiotic regularity and fertility will complicate selection work on wheat-rye amphidiploid material.