Spring Rye Research Articles

REACTION OF TRITICALE AND SPRING RYE TO LOOSE SMUT OF WHEAT

Twenty-seven lines of triticale (Triticale hexaploide Lart.) were inoculated with a mixture of races T1 to T5 of loose smut of wheat (Ustilago tritici (Pers.) Rostr.); six lines were susceptible with the level of infection ranging up to 67%. The race virulent on three of the lines was found to be T4, a race characterized by virulence on cultivars of durum wheat (Triticum turgidum L.). Of 119 cultivars of spring rye (Secale cereale L.) that were inoculated with the mixture of races, 68 were infected. The races virulent on five cultivars were found to be T2 on four, and T4 on one. The level of infection ranged up to 37%.

Multivariate statistical analysis of yield, its components and characters above the flag leaf node in spring rye

The relationships between yield and its components and structures above the flag leaf node were studied in an 8 X 8 diallel of spring rye (Secale cereale L.) by the use of multivariate statistical procedures. Stepwise multiple regression analysis showed that flag leaf characters did not account for significant amounts of variability in yield or its components. Principal component analysis showed no association between yield (and its components) and flag leaf characters while the canonical correlation between the two sets of characters was significant.

THE DURATION OF MEIOSIS IN DIPLOID AND AUTOTETRAPLOID BARLEY

The duration of meiosis and its constituent stages are given for diploid and autotetraploid Ymer barley grown at 20 °C in continuous light. In the diploid, the total meiotic time was about 39 ± 1 hr in both cultured anthers and on whole plants. In the tetraploid, the total meiotic time was about 31 ± 1 hr in cultured anthers. In both genotypes, each meiotic stage occupied about the same proportion of the total meiotic time as in other species.In unsampled anthers the tapetal nuclei divided synchronously while the pollen mother cells were at pachytene and each tapetal cell became binucleate. Normal development in the tapetum and archesporium was much more easily upset by sampling techniques during pachytene than at any other stage.The duration of meiosis in diploid Ymer agrees closely with our previous estimate for diploid Sultan barley. The shorter meiotic duration of the auto-tetraploid compared with that of the diploid is to be expected in the light of the decreased meiotic time of tetraploid Svalöf 4x rye compared wih diploid Petkus Spring rye (Bennett and Smith, 1972) and the interspecific comparisons of meiotic times made by Bennett (1971).The development timing differential between adjacent spikelets was much less during meiosis than at the primordial stage.Abnormal tetrads which occurred spontaneously at a low frequency in tetraploid Ymer are discussed. They were probably associated with spindle abnormalities.

THE EFFECT OF TEMPERATURE ON MEIOSIS AND POLLEN DEVELOPMENT IN WHEAT AND RYE

The durations of meiosis and pollen development were estimated in Petkus Spring rye and Chinese Spring wheat grown at 15, 20 and 25 °C. Over the range 15-25 °C, meiotic duration and pollen maturation time decreased with increasing temperature and the ratio between the durations of these stages at 25 °C and at 15 °C (Q10) indicated that the temperature responses of meiotic and pollen development were similar in both species. Both within and between species meiosis and pollen maturation had constant relative durations at each temperature. The effect of low temperature on the duration of meiosis and pollen development was similar in Holdfast, an extreme type of winter wheat, as in Chinese Spring. The relevance of these results to hybrid cereal breeding are mentioned. In plants grown at 25 °C, abnormal meiotic and pollen development resulting in male sterility was seen in some anthers. The cause of male sterility appeared to be thickening of tapetal cell walls concurrent with abnormal late meiotic development in PMC's.

The effects of polyploidy on meiotic duration and pollen development in cereal anthers

The anther is useful for the study of development because it provides comparisons between mitotic and meiotic divisions; between nuclear behaviour during the sporophyte and gametophyte stages; and between cell cycles and divisions involving cells with different nuclear DNA contents. The duration of the period from the immediately premeiotic mitosis until the start of leptotene at 20 °C was estimated to be about 48 h in hexaploid Chinese Spring wheat (Triticum aestivum), and about 42 h in diploid Petkus Spring rye (Secale cereale). Comparisons of the durations of meiosis and of pollen maturation in wheat, in rye and inTriticalegenotypes showed that in all three the durations of these stages of development decreased as ploidy level increased. Within each ploidy level, genotypes with higher nuclear DNA content had longer meiotic durations. Differences in both meiotic duration and pollen maturation resulted from proportional differences in the duration of all component stages. These results obtained from comparisons of a closely related group of species in the Gramineae are similar to the results obtained previously (Bennett 1971) from comparisons of plant species taken from widely different families. Data in animals showing positive linear relationship between meiotic duration and the duration of spermatogenesis are collected. Possible causes of the faster rates of development during meiosis and pollen maturation in polyploid cereal species, and of the constant proportions between the durations of all their constituent stages, are discussed.

Seasonal Fluctuations in Population Densities of Pratylenchus Penetrans Under a Rye-Tobacco Rotation in Ontario 1)

Seasonal changes in soil and root population densities of Pratylenchus penetrans (Cobb), and changes in soil moisture and temperature, were studied at weekly intervals for 28½ months under a rye-tobacco rotation in Ontario, Canada. In general, population densities tended to be low in the summer and high in the fall, but the seasonal changes were not consistent from year to year. The results indicate that it is very difficult to predict population densities much in advance of the tobacco crop and that density determinations should, therefore, be made in the fall or spring rye crop prior to tobacco planting. Winter mortality of P. penetrans in both soil and roots ranged from 40-65%. Fall and winter fallow in place of the normal rye cover crop reduced the number of P. penetrans and increased the growth of the ensuing tobacco at mid season.

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.

INTERACTION OF RED AND FAR-RED RADIATIONS WITH THE VERNALIZATION PROCESS IN WINTER RYE

Flowering of winter rye was advanced and the final leaf number reduced by red radiation (ca. 660 mμ) given to grain germinated at low temperatures for 4, 6, 8, or 9 weeks, and by far-red radiation (ca. 740 mμ) given during 3 weeks' low temperature treatment. Radiation was without effect on flowering when given during low temperature treatment continued until the grain was fully vernalized, when given during low temperature treatment of grain of spring rye, when given to grain of spring or winter rye maintained at 15 °C, and when given during thermal de-vernalization of winter rye.It is concluded that the phytochrome system is not involved in the flower-promoting effect of low temperature (vernalization) but that radiation given during low temperature treatment of germinating grain may enhance the stabilization of the vernalized condition.

Notes on the value of spring rye for cultivation

Spring rye proved to be slightly earlier than spring wheat. The straw of spring rye was longer and weaker than that of spring wheat, on the other hand it was shorter and stiffer than that of winter rye. The yielding capacity of spring rye was only about 2/3 of that of both spring wheat and winter rye. The kernel properties of spring and winter rye proved about equal. Because of its low yielding capacity spring rye can not be recommended for cultivation on productive soils in South Finland.

Effect of Gibberellin on the Flower Initiation and Stem Extension in Petkus Winter Rye

THE cold requirement for flower formation in biennial Hyoscyamus niger was shown by Lang1 to be replaceable by application, of gibberellin, but no flowering response was observed at that time in either Petkus winter or spring rye similarly treated2. In 1958, I attempted to supplement partial vernalization in Petkus winter rye by a single injection of gibberellic acid (10 p.p.m.) through the third leaf. No effect on flower initiation was observed. Stem extension was unaffected in the unvernalized controls but considerably enhanced in the partially vernalized series. In 1959, further work was carried out to determine whether the lack of response was due to the low concentration of the single application of gibberellic acid, or whether stimulation of stem extension demanded some prior degree of flower initiation.

THE USE OF CEREAL GRAINS AS COMPANION CROPS IN DRYLAND FORAGE CROP ESTABLISHMENT

The effect of wheat, oats, barley, and spring rye as companion crops on the establishment of a perennial forage crop mixture consisting of crested wheatgrass, brome, and alfalfa under arid conditions compared to no companion crop was studied at Swift Current, Saskatchewan. Cereal companion crops reduced the vigour, stand, and subsequent early forage yields of the grass-alfalfa mixtures, but less so if the cereal crop and the forage crop were seeded separately at right-angles to one another. The method of harvesting the cereal companion crop also influenced the performance of the subsequent forage crop. Cutting the cereal crops at a height of 8 inches or more for grain resulted in better grass-alfalfa stands and yields than was obtained when the cereal crops were mowed at a 2-inch height for hay. The effect of kind of cereal grain on performance of the perennial forage differed little. Wider row spacings for the cross-seeded companion crops also resulted in a better stand and yield of the grass-alfalfa crop.

Cytological Studies of Hybrids Involving <i>Triticum durum</i> and <i>Secale cereale</i>

The allopolyploid of T. durum var. Carleton and Secale celeale (spring rye) was crossed to the T. durum varieties Iumillo, Stewart, F.P.I. 94587 and Golden.A single hybrid each was obtained from the crosses involving Stewart and F.P.I. 94587. Fourteen bivalents and seven univalents were the most frequently observed configuration in the pollen mother cells. A quadrivalent in the form of a ring of four chromosomes was observed in some of the pollen mother cells. Genome constitution of these hybrids is believed to be AABBS.Five hybrids between Triticale and lumillo were obtained. Four hybrids had 32 and one hybrid had 31 somatic chromosomes. All hybrids lacked the hairy neck character. A quadrivalent in the form of a ring of four chromosomes was observed in the pollen mother cells of the hybrids. The genome constitution of the 32 and 31 chromosome hybrids is postulated to be AABBS-3 and AABBS-4 respectively.Two BC1 plants with 28 wheat chromosomes plus 1 rye chromosome were obtained by backcrossing hybrids 35-1 to Khapli. The presence of the rye chromosome resulted in plants with thin culms and narrow leaves.An individual with 28 wheat chromosomes plus chromosome I of rye was obtained by backcrossing hybrid 37-1 to Khapli. The presence of the rye chromosome adversely affected plant height and increased the frequency of asynapsis of one or two pairs of wheat chromosomes.Quadrivalents observed in the hybrids involving durum varieties are believed to be due to a reciprocal translocation present in the Triticale parent.

Effects of Diffusate Obtained from Vernalized Winter Rye Seeds

In this experiment, the effects of Diffusate which is assumed to contain flower promoting substance was investigated. The substauce was slowly diffused out from vernalized rye-seeds into deionized sterilized water at a cold dark room avoiding contamination of microorganism. Washed air was continuously supplied into water for four weeks until Diffusate was collected. The heading of spring rye plants when treated with Diffusate was found about two weeks earlier than that of the control plants. Spring rye was used as a tester of Diffusate-efficiency in this case. Winter rye grains were intersected at the center and were divided into two parts i. e. embryo +endosperm (part A) and endosperm (part B). Then Diffusates were collected from both A and B, and were named D-A and D-B. Three kinds of method were taken for applying D-A or D-B; (1) soaking the seed in the substance, (2) contacting a piece of cotton wet with it to the coleoptile-tip and (3) injecting it into the stems of winter rye seedlings. As shown in Fig.4, both D-A and D-B accelerated the heading of winter rye, and D-A strongly accelerateds the stem growth in lengths.

Studies in Vernalisation of Cereals

The photoperiodic reactions of spring rye and vernalised and unvernalised winter rye have been studied in detail and interpreted in terms of a schema presented in earlier papers. Vernalisation treatments ranging from 0 to 13 weeks were used and three daylengths (continuous light, C.L.; normal days, L.D.; 10-hr. days, S.D.), and the interaction effects of these factors were studied on the following developmental features: time to initiation of flowering and to ‘double-ridge’ formation; progress of differentiation and growth rate of the apex of the main shoot before and after initiation. Systematic dissections of the apex were carried out to obtain data for this study. The validity of the concept of ‘minimal leaf number’ was re-examined and confirmed by using dwarf embryos with subnormal numbers of primordia at germination. Unvernalised winter rye was shown to behave as a short-day plant before flower initiation since photoperiodic induction by short days is annulled by interrupting the dark period by a short light period at low intensity. The effect of exposure of a single leaf to continuous light, while the remainder of the plant was kept in short days, has been shown to be transmitted to the apex and hastens both flower induction and spikelet development in fully vernalised rye. Vernalised winter rye and spring rye thus behave as long-day plants.

Studies in Vernalisation of Cereals

Petkus winter rye crossed with Petkus spring rye gives a first filial generation in which the spring habit is completely dominant, while in the second filial generation ‘spring’ and ‘winter’ plants occur in approximately the ratio of 3 : 1. In the F2 generation within the ‘spring’ and ‘winter’ classes there is a dispersion of flowering-dates, suggesting a less simple inheritance. Pending further investigation, this is explained on the basis of independent segregation of factors for early and late ripening as distinct from the spring and winter habit.

Devernalization of Spring Rye by Anærobic Conditions and Revernalisation by Low Temperature

A PREVIOUS letter in NATURE1 presented evidence to show that in winter rye (var. Petkus) anaerobic conditions at normal temperatures (20° C.) when alternated with aerobic conditions at 1° C. quantitatively annul the vernalizing effect of low temperature. It appeared possible, therefore, that spring rye of the same variety might be devernalized by the application of anaerobic treatment at 20° C. Previous work2,3 has shown that the process of vernalization in winter rye decreases the number of leaves produced on the main axis before flower initiation, as well as decreasing the period of time required to reach anthesis. An increase in these characteristics in spring rye after anaerobic treatment would thus indicate a process of devernalization.

A QUANTITATIVE STUDY OF THE ROOTS AND ROOT HAIRS OF A WINTER RYE PLANT (SECALE CEREALE)

AS AN element of the plant cover, grasses are efficient as soil binders and occupy a particularly prominent place in erosion studies. Their compact fibrous root systems develop mainly in the upper soil levels which gives them a very advantageous position in soil binding. Fortunately their economic importance as field and forage crops makes their cultivation porfitable from an agricultural standpoint as well as from one of soil conservation. The investigations by Weaver and his associates (1926) have given a general picture of the subterranean parts of many plants. Reports of these investigations deal more particularly with the horizontal and vertical distribution of root systems. A recent paper by Pavylechenko (1937) is one of the first attempting a quantitative survey of the roots of a mature plant. In this study, dealing with competition between weed and crop plants, Pavylechenko reports the total root length of several individual field grasses -namely, wild oats, 54.3 miles; Marquis wheat, 44.2 miles; and Prolific spring rye, 49.1 miles. These figures were based upon measurements of single plants grown widely separated. The survey of the root systems of these plants did not include all roots. Pavylechenko states there were further subdivisions which were neither counted nor measured. Had these, the quaternary roots, been included, the total figures would certainly have been much higher, probably doubling his reported totals. In general the work on root hairs has been carried on by a group of investigators whose interests have been mainly in growth responses as influenced by external factors, and apparently none of them has made a count of root hairs for an entire well-developed plant. This paper gives the figures for the root and root hair systems of a single cereal plant, Secale cereale L. Of several grasses studied in a preliminary waynamely, Andropogon furcatus Muhl., Sorgastrum nutans (L.) Nash., Poa pratensis L., and Triticum sativum L.-winter rye was selected because it has been used successfully in retarding erosion and also because of its importance as a grain and forage crop. Studies in progress deal similarly with several other grasses. The seedling of winter rye produces a whorl of four primary roots. These function for a number of weeks but disappear later as numerous permanent adventitious roots grow out from the base of the stem area and become the main roots of the plant. Branches from these are the more numerous secondary roots which in turn give rise to the tertiary

SOME CONSIDERATIONS IN REGARD TO EXPERIMENTS WITH CHEMICAL HERBICIDES

The writer reviews the subject of weed control by chemicals in the growing crop mainly with reference to prairie conditions, and discusses it under the following heads: the herbicide, the sprayer, weather conditions, the crop, the experimental technique. A technique is described which permits the analysis of a large group of variable factors in the weed-control experiments carried on in Saskatchewan.An extensive program of weed research was undertaken in Saskatchewan in 1929, to determine the practicability of both methods of control by chemicals (control of perennial weeds in small patches, and control of annual weeds in the crop) under semi-arid conditions and with extensive farming methods. The experiments were conducted under the most variable conditions of soil and climate, and many chemical solutions were tested at varying concentrations and amounts of spray per acre. Treatments were made on stinkweed and wild mustard in wheat, oats, barley, rye, corn, sweet clover, western rye grass, alfalfa and brome grass. During the last three years the effects of the following chemicals have been studied: sodium chlorate, sodium dichromate, copper nitrate, copper sulphate, sulphuric acid, iron sulphate, sodium chloride and ammonium bisulphate. All of these, except the last, reduced the weed infestation of the treated crops; the chemicals are listed in order of effectiveness. The results showed, however, that many factors other than proper strength of solution and amount of spray per acre should be taken into account.The largest percentage of control of wild mustard in the crop of 1931 was obtained with weak solutions of sodium chlorate. The effects of this chemical on the crop are more severe than those of the others, and therefore its use should be further investigated before it can be recommended.The application of dry chemicals for control of weeds in the crop combine in general two farming operations—fertilizing of the soil and weed control. These methods offer little promise for Saskatchewan as they require cool, foggy, wet weather which is rarely found in the west; and because it has been found that, in order to be effective here, commercial fertilizers have to be drilled in with the seed and not broadcasted on the surface.It appears that, under Saskatchewan conditions, only a few weed species can be controlled successfully. In wheat, sulphuric acid will control common wild mustard, Indian mustard, wild radish, stinkweed, false flax, tumbling mustard and wild buckwheat. New shoots of Canada thistle are somewhat retarded in their development. Hare's ear mustard, ball mustard, cow cockle, lamb's-quarters, Russian pigweed, and the grasses, wild oats, darnel, etc., could not be controlled under the conditions of these experiments. It is thus important that chemical treatments be limited to fields where weed infestation consists mostly of susceptible weeds, because in controlling these the crop and resistant weeds are stimulated. At Watson, Sask., in 1931, when wild mustard or stinkweed was associated with either wild oats, lamb's-quarters or Russian pigweed, there was always an increase in the development of the latter weeds after treatment.In these experiments the cereals ranked as follows in resistance to sulphuric acid sprays:–resistant; wheat, oats: intermediate; barley, spring rye: susceptible; corn.

VEGETATIVE PROPAGATION OF WILD OATS, AVENA FATUA, AND OTHER ECONOMICALLY IMPORTANT SPECIES OF AVENEAE AND HORDEAE

Following the discovery that small sections of wild oats seedlings could become rerooted and develop into normal plants, a study was undertaken to determine from what part or parts of the seedlings new growth can originate, and whether cultivated oats, wheat, barley and spring rye, would behave in a similar manner. Special attention was given to the problem of vegetative propagation in wild oats as a factor in the control of this weed.Small sections of wild oats seedlings, one inch in length and containing the coleoptile node, became rerooted under favorable conditions and produced fully developed plants. Cultivated oats behaved in a similar manner to wild oats in this respect, but the latter produced the more vigorous growth.When land is infested with wild oats and is plowed shallow, or cultivated shortly after the seedlings have emerged from the soil, a considerable proportion of them, under certain conditions, may produce new plants by vegetative regrowth. The extent to which this may occur in the field depends largely on the soil moisture as well as on other conditions which facilitate rerooting, such as shallow plowing, and packing when conditions for plant growth are favorable.With young seedlings of wild oats at time of emergence, regrowth occurred mostly from a small area located between ground level and one inch below the surface. The same was found to be true of cultivated oats. With seedlings of wheat, barley and spring rye, at time of emergence, regrowth originated only from nodal tissue close to the seed. The difference in this respect, between oats, Aveneae, on the one hand, and wheat, barley and rye, Hordeae, on the other, is due to the fact that the area of elongation in oats is the mesocotyl, whereas in other cereals it is the first internode.At later stages in seedling development of both oats and the other cereals, nodes which were capable of regrowth developed immediately below and above the ground level. With older seedlings in the first-, second-, and third-leaf stage, the youngest node above ground, which is the one nearest the soil, had the greatest power of regrowth.