Die Arbeit behandelt die gegenseitige Beziehung zwischen Hanf und Roggen in Wasserkultur bei nicht ergänzter Mineralernährung. Nach 18-tägiger Kultivierung in Nährlösung mit³²P wurden beweiskräftige Phosphorsorptions- und Transpirationsdifferenzen zwischen den Kontrollpflanzen und der Mischung gefunden. Die Hanf-Kontrolle verbrauchte in 18 Tagen 85,5% Phosphor, Hanf in der Mischung 94%, die Roggen-Kontrolle 95,3%, Roggen in der Mischung 106,7% auf je eine Pflanze umgerechnet. Das Wachstum wurde nicht beeinflusst. Die Ergebnisse lassen sich nicht bloss durch Nährstoffkonkurrenz zwischen den beteiligten Arten, sondern durch die Anwesenheit eines weiteren Faktors erklären.

Mit Ultrarot-Absorptionsschreibern für CO₂ und H₂O wurden die apparente Photosynthese, die Respiration und Transpiration von Maispflanzen und-blättern unter konstanten Bedingungen untersucht.
Zwischen den 3 geprüften Sorten, "Schindelmeiser", "Siloma" und "WIR 25" ergaben sich keine signifikanten Sortenunterschiede hinsichtlich der apparenten Photosynthese obwohl sich die Sorten-bedingt durch die unterschiedliche Vegetationsdauer-in den Erträgen deutlich unterscheiden; die Einzelpflanzenstrenungen innerhalb der Sorten lagen bei 25%.
Bei fast gleich grosser Einzelpflanzenstreuung innerhalb der Sorte zeigte sich eine signifikant
Bei fast gleich grosser Einzelpflanzenstreuung innerhalb der Sorte zeigte sich eine signifikant höhere Transpiration bei "WIR 25" als bei den beiden anderen Sorten. Die höchste apparente Photosynthese wiesen die Blätter auf, die dem Kolben am nächsten inseriert waren (4.-5. Blatt).
Die CO₂-Aufnahme je Blattfläche und Stunde war bei den verschiedenen Abschnitten des Blattes unterschiedlich; im Mittelteil wurden signifikant höhere Werte als im basalen Teil der Blattspreite beobachtet. Die CO₂-Aufnahme korrelierte positiv mit der mineralischen Ernährung.
Es gab keine Unterschiede in der CO₂-Aufnahme bei den Pflanzen ohne und mit Kolben. Bei Pflanzen ohne Kolben können die produzierten Assimilate (Saccharose) nicht gespeichert werden; sie überschwemmen deshalb die ganze Pflanze und werden zu einem grossen Teil nachts veratmet. Der effektive Stoffgewinn an Trockenmasse dieser kolbenlosen Pflanzen erreicht nur 70% von denen mit Kolben.

Agar-gel electrophoresis was used for studying the protein fractions of apple-tree blossom and leaf extracts and some qualitative differences were found. The finding is discussed in connection with flower-bud differentiation.

Plants of ten varietal populations of maize and their progenies in S₃ generation had been evaluated for their resistance to sources of corn smut in conditions of increased infection level. According to the infection degree, the experimental material was divided into classes (I-V) corresponding to five categories of resistance.
The relative representation of progenies from populations differing in their susceptibility to the parasite in their particular classes showed that the heterozygous varietal populations posses some imunological structure.
1. In the composition of the populations the resistant forms prevail over the susceptible ones. In the populations studied 82.8-98.5% dissected at selfing were grouped into classes I-III.
2. The basis of resistance of populations is formed by a group of forms ranged into the second class of resistance. This group being equally represented in all populations (31.1-40.8%) independently of their susceptibility to corn smut.
3. The differences in disease attack of plants of the particular populations had been influenced by the relative participation of selfed progenies, ranged on the one hand into class I and on the other hand into classes III and IV. The occurence of progenies in these categories in populations arranged consecutively from higher to lower resistance varied in conformity on extent 46.2-15.5%, 11.5-37.5% and 1.5-17.8%.
The experimental data showed, among others that the general smut attack of plants in populations (23.5-49.6%) corresponded in most instances to the average attack of progenies in S₃ generation (21.0-44.2%).

Whereas experiments directed towards proving the infectious character of the hop curl disease did not give reliable proof of its virus character (we have not been able to transfer it neither by cuttings nor by graft), but made possible its differentiation from the English nettlehead hop virus disease, the practical experiences and results presented in this paper show that nutritional conditions essentially affect the known variability of the external manifestations of the hop curl disease. Especially such nutrients play a role which with the normal fertilising techniques are not returned to the soil in sufficient quantity. Since the hop curl disease was noticeably inhibited in a nutritional field experiment on application of the salts of some elements, predominantly of B, Mg, Mo, Mn, Ni, I and Zn, it appears possible to apply "symptomatic therapy" of the hop curl disease, which could have wide practical importance for limiting this disease.
In order to supplement the provocation field experiments, comparative investigations of the chemical composition of the leaves from healthy and hop curl diseased plants were carried out. Quantitative analysis of the biogenic elements carried out by the usual methods and by polarography showed a regularly higher content of P, K, Ca and a lower content of Zn in the diseased plants as compared to healthy ones. The differences observed in the content of N, Na, Mg, S, Fe and Cu were not always in the same sense. Chemical analysis was accompanied by parallel spectral analysis of ash. This made it possible to obtain a considerably complete survey of the qualitative and approximately quantitative representation of a whole series of other elements in healthy and diseased plants; however, no characteristic differences were recorded.
Finally the results obtained in the present work are confronted with the findings of other researches, especially from Germany, and discussed.

1. In tetraploid Phaseolus sp. × P. calcaratus cross, shrivelled but viable seeds were produced. One hybrid was raised but it died within a month. Another hybrid was raised to flowering by artificially culturing the embryos before shrivelling.
2. The F₁ of tetraploid Phaseolus sp. × P. calcaratus cross, had various leaf abnormalities at an early stage. In most of the characters the hybrid was intermediate between the two parents. The twining habit of P. calcaratus dominated in the hybrid. The F₁ plant had 10.7 per cent pollen fertility. The hybrid died within a week of flowering.
3. In P. calcaratus × tetraploid Phaseolus sp. cross, rudimentary, non-viable seeds were produced.
4. The incompatibility barriers are active - (a) at post-fertilization stages causing shrivelled and rudimentary seeds and (b) in the F₁ generation causing hybrid lethality and sterility. The importance of embryo culture techniques in removal of the first type of crossability barriers is stressed.

Relationship between roots and shoots ofPimpinella saxifraga L.,Petroselinum hortense Hoffm.,Lactuca sativa L., andBeta vulgaris subsp.esculenta (Salisbury) Gürke var.altissima Roessig was studied in irrigated and non-irrigated plants. It was found that the irrigation water did not influence distinctly the root-shoot ratio of the experimental plants. From the statical point of view, this relationship could be expressed by the following quantitative ratios for irrigated and non-irrigated plants: 3∶1 forPimpinella saxifraga L., 2∶1 forPetroselinum hortense Hoffm., 9∶1 forLactuca sativa L., and 1∶1 for beetroot. From the dynamic point of view it is possible to state that this ratio changes in the course of individual development. With plants cultivated for their aerial parts, it increased with age, while with plants cultivated for their roots, it decreased with age. The irrigation water produced much greater morphological changes (the shape and the surface area) in the root and shoot system of experimental plants.

The effect of different exposures to RTG radiation (100 r, 250 r, 500 r, 1000 r, 2500 r, 5000 r) on the changes of the permeability of the epidermal cells ofAllium cepa L., variety Všetaty, bulbs was studied during three vegetation periods. Bulbs from growing plants (followed from the development phase of bulb growth) and bulbs immediately after harvesting were used for the experiments.
It was demonstrated in our experiments by plasmolysis that the radiation-induced changes of cell permeability were irreversible. When plasmolytic agents of non-electrolyte character (1M sucrose, 1M glycerol, 1M urea) were used, the equilibrium state (total plasmolysis) was reached more rapidly with the irradiated bulbs than with the unirradiated controls. When electrolytes were used (0.5M KNO₃, 0,5M KBr), total plasmolysis occurred less rapidly with the irradiated objects than with the controls. These relationships were manifest during the whole ontogenesis ofAllium cepa L. An exposure to 100 r was sufficient in our experiments for causing the mentioned changes, proving a considerable sensitivity of the osmotic properties of the epidermal cells ofAllium cepa L. bulbs to ionizing RTG radiation.
Plasmolytic experiments after smaller exposures than 100 r of RTG-rays are in preparation.

The authors investigated the transport and localization of radioactive phosphorus in ownroot and grafted fruit trees. Radioactive phosphate was usually applied to conductive tissues of a thinner root (about 5-8 mm. in diameter). By periodic measurement of the radioactivity of leaves, the localization of radioactive phosphorus was determined in all top branches, and after 2-2.5 months in the four opposite sectors of the root system.
The experimental trees were grafted fruiting apple trees from 6 to 8 year-old (24 trees), own-root 5-6-year-old apple-trees (20 trees), own-root 4-6-year-old plum-trees (4 trees) and grafted 4-6year-old apricot-trees (4 trees). By applying radioactive phosphorus directly to the conductive tissue of roots a high radioactivity of some top branches was achieved, which made it possible to examine the localization of radioactive phosphorus in the tree-top and in tree roots two to three months after application.
As with separated nutrition (Belavin 1958), radioactive phosphorus injected into a thinner root is transported to most top branches, but most of it is localized only in some of them. After a two-month exposure, no marked equilibration of phosphorus concentration is observed to take place among the principal top branches.
It was demonstrated by measuring the radioactivity of 4 opposite sectors of the root system of grafted trees (16 apple and 4 apricot trees) that two months after exposure radioactive phosphorus can also be found in the roots of the sector opposite to that where radioactive phosphorus had been applied.
It was found by autoradiography that radioactive phosphorus is transported by a definite part of trunk xylem. A small portion, however, is transported horizontally through the trunk. No significant difference was found between own-root (no seedlings) and grafted trees with respect to the transport and localization of radioactive phosphorus. After a certain time the tree distributes the radioactive phosphorus throughout the organism, but the half-time of³²P does not permit of tracing its transport from the root system to the entire top during the subsequent vegetation season.

Six-day leaves of wheat (Triticum vulgare) were used to test the effect of oxygen, nitrogen and different mixtures of these gases, methylene blue and L-cysteine on the inhibition of respiration by sodium fluoride and monoiodoacetic acid using the Warburg manometric method. In an atmosphere of 100% oxygen total respiration was increased by an average of 45%, 10% oxygen led to a decrease in respiration by 20%. However, no simultaneous changes were found in the degree of inhibition by these enzyme poisons. On decreasing the oxygen content to 5% inhibition of respiration was almost doubled while at the same time respiration fell by an average of 23%. In nitrogen, the respiration rate varied around 10% and inhibition was almost 100%. The results showed that the action of enzyme poisons is only influenced by different oxygen content at low oxygen tension and is evidently associated with the dominance of a given energy system (glycolysis).
On using methylene blue and L-cystein in concentrations of 10-3M a decrease in the relative inhibition of respiration by enzyme poisons was also found. The total respiration rate, however, was only raised by 6-8%. Since the change in the degree of inhibition on using these substances is caused by an increase in the participation of respiratory processes resistant to glycolytic inhibitors it can, in this case be assumed that there is an increase in the activity of the pentose cycle in such tissue.

The pathophysiology of tomato plants infected with potato witches' broom was studied. Changes in dry weight, content and composition of ash and the amount of different phosphorus and nitrogen fractions were investigated. All analyses were carried out separately in leaves, stems and preliminarily also in flowers. Considerable disproportions found in the distribution of metabolites among the individual organs investigated correspond to a great extent to the morphological picture of the disease. The leaves of diseased plants are actually starving and their growth and development are greatly inhibited. On the other hand, the stems are overflowing with metabolites, in particular with nitrogenous ones. They are thickened and along their entire length rootlets and sprouts appear forming the characteristic brooms. The authors assume that the disturbances in flower formation in diseased plants are due to the lack of essential metabolites. Diseased plants contain an increased amount of alkaline metals and alkaline earths.

1. The relation between the manifestation of the factors for the row number, development and fertility of lateral florets and kernel weight of barley was investigated.
2. Kernel weight was found to depend on the number of rows as well as on the development and fertility of the lateral florets.
3. The possibility of a genetic linkage between the factors for row number and kernel weight was discussed.

As lipids can be a source of artefacts during intracellular localization of enzymes by cytochemical methodsin situ it was the aim of the present work to obtain orientation data on the distribution of lipids in the meristematic plant cells. The different fixation and object embedding methods examined revealed that it is best to fix the material by some formol fixative and without chroming, to embed it in polyethyleneglycol media. An alcoholic solution of Sudan black was found to be most reliable. In the meristematio cells the cytoplasm is usually stained more intensely than the nucleus. The ground cytoplasm is stained weakly while cytoplasmic particles are stained intensely. In some cases an intense black staining of nuclei, particularly in the prolongation zone, can be achieved. The staining intensity of cell components does not decrease on extracting lipids with pyridine. After extracting the dye from stained cell components a browninsh residual coloration remains. Chromatography of Sudan black revealed in all the samples tested slowly moving spots (blue and violet) and rapidly moving ones (red II, yellow, red I, colourless).

Im Jahre 1900 veröSentlichte ich einen vorläufigen Bericht über durch Schwerkraft bewegliche Stärkekörner in bestimmten Pflanzenzellen, die man als tierischen Statozysten analoge Vorrichtungen ansprechen könnte. Über diesen Gegenstand erschien 1901 meine ausführliche Arbeit, in welcher ich eine auffallende zytologische Reaktion beschrieben habe, die in stärkeführenden Columellazellen der Wurzelhaube bei geotropiseher Reizung erscheint: Diese Reaktion, welche ich als ein Symptom, dass die erwähnten Zellen den Schwerkraftreiz zu rezipieren vermÖgen, betrachtete, wurde später sehr selten nachuntersucht und ist vergessen worden. Erst im Jahre 1962 veröffentlichte AUDUS neue Angaben über dieselbe und zwar auf Grund von elektromikroskopischer Untersuchung der Statozyten in Wurzelhauben.
Die vorliegende Mitteilung bringt zum ersten Mal mikrophotographische Aufnahmen der zytologischen Georeaktion und erwähnt neue Versuche, welehe zu Gunsten der Ansicht sprechen, dass die zytologische Georeaktion durch Druck der Statolithen auf die äussere Zytoplasmahaut der Statozyten ausgelöst wird. Es wird auch darauf hingewiesen, dass nicht nur spezifisch schwerere, sondern auch spezifisch leichtere Körperchen als Statolithen, welche eine Georeaktion auszulösen fähig sind, fungieren könnten.

A water-soluble germination- and growth-inhibitor present in plants of Brassica genus was studied. Aqueous eluates from chromatograms of methanolic extracts of Savoy cabbage, cabbage and Brussels' sprouts leaves, and of Brussels' sprouts roots, inhibited the growth of wheat; the chromatographic behaviour of this inhibitor was similar to that of the thioglycoside glucobrassicin (GLUBR). GLUBRat 10^-3 m, and the supposed product of its enzymatic degradation, 3-indolylacetonitrile (IAN) at 10^-4 m, inhibited the growth of wheat and clover in a similar manner. At lower concentrations, both substances gradually enhanced growth. In contrast to IAN, GLUBR did not appreciably influence the growth of Savoy cabbage. Other products of GLUBR degradation, such as thiocyanate ion and ascorbigen, influenced the growth to a lesser extent and in a different way. At higher concentrations GLUBR and IAN also inhibited the germination of clover seeds. The biological effect of GLUBR is dependent on the presence of the indole nucleus in its molecule; the thioglycoside glucoiberin, which is not of indolic character, does not influence growth. The presence of free myrosinase was shown in intact wheat seedlings. Hence, GLUBR taken in by the germinating plants must undergo enzymatic cleavage. The in vitro activity of myrosinase in wheat and clover was lower than in Savoy cabbage, but the quantity of IAN formed at a pH corresponding to the natural pH was higher in wheat and clover than in Savoy cabbage, where the formation of the growth-inactive ascorbigen prevailed. On the basis of these results the hypothesis was formulated that GLUBR, the indolic complex from the generaBrassica, Raphanus, Cochleria, Nasturtium, Barbarea andSisymbrium, is a representative of a class of potential inhibitors of growth and germination, whose activity can be explained by the liberation of large amounts of growth-affecting substances during their specific enzymatic cleavage.

An investigation was made of the anatomical structure of the shoot apex ofSenecio vulgaris L. a photoperiodically neutral plant, and compared with the formation of successive leaf primordia along the axis up to the initiation of the terminal inflorescence. In the shoot apex of a germinating plant a central zone can first be distinguished from the peripheral zone which is composed of small and intensely stained cells. Later, a rib meristem appears. At the time of the initiation of the middle (the largest) leaves, the shoot apex has a distinct small central zone and a well developed peripheral zone and rib meristem. Between these zones there is a group of cells dividing in all directions, the subcentral zone. At the time of initiation of the last leaves, the central zone extends to the flanks and gradually ceases to be distinguishable. At the same time, the subcentral zone increases in size. This is caused first by cell division and later, with the initiation of the last, most reduced leaves, by enlargement of the cells. Vacuolization in the inner part of the apex and the arrangement of the superficial cells in rows parallel to the surface of the apex, is a preparatory step to the initiation of the inflorescence.

A very low, for the most part unmeasurable glutamic-aspartio transminase activity and a very high glutamic-alanine transaminase activity was found in the overground parts and roots of young wheat plants. The roots had a higher glutamic-alanine transaminase activity than the overground parts in the first and second leaf stage.
Plants cultivated in Knop's nutrient solution (variant with humate and without) showed a higher glutamic-alanine transaminase activity than poorly growing plants, cultivated in distilled water (with humate and without). In plants cultivated in nutrient solutions, transaminase activity increased with the age of the wheat plants.
As in the previous experiments, the effect of humate was only significant, in the roots of plants cultivated in distilled water with humate, where transamination activity was greater than in the control without humate. The roots of this variant with a stimulatory growth effect showed a large accumulation of free sugars in the previous experiments.
The connection between these effects of humate on the roots of young winter wheat plants is discussed.

A study was made of the effect of substituting a short day for vernalization as a varietal characteristic of winter wheat. Varieties representing certain ecotypes were vernalized for different lengths of time and it was studied how a short day can replace or accelerate vernalization. At the same time data were obtained on the effect of a short day on individual criteria of growth. The results showed that there are ecotypes in which a short day does not replace vernalization (the varieties San Pastora and other Italian varietis). In this case growth inhibition did not occur either. Otherwise it usually accompanies the substituting affect of a short day. This finding permits the interpretation of varietal differences observed in association with short day growth inhibition and changes in carbohydrate metabolism conditioned by it. Growth inhibition produced by a short day is a general reaction which is not only associated with vernalization. The author found varieties (Chlumecká 12) in which growth was inhibited by short day without accelerated development occuring (alternative types).

The seeds contain such a high percentage of phosphoric acid that it interferes with the obtaining of correct results in analysis. Its prior removal from the solution of ash is therefore necessary. A new method is suggested for the entire analysis which is a combination of percolation through an ionexchanger column and colorimetric and gravimetric determination.
The oxide values and the average content of ash per 100 g. dry weight of seeds ascertained by analysis were used to calculate the weight of each determined element per 100 g. of dried substance.
The analysis showed that traces of tin are present in the ash of the seeds tested.
Under the given conditions each species maintains its characteristic way of storing ash constituents in the seeds and this is not obviously affected by the affinity of the plants or the influence of the soil.

The barley variety "Browarny P.Z.H.R." was grown in pots. Experiments on the course of development were conducted for two years. The increase in the dry weight of roots, leaves, stems and grain was recorded. The assimilation area of the plants was measured periodically and the rate of respiration in detached leaves was determined. Photographic records were kept of growing point and ear development. The dynamics of growth and development were studied during the whole vegetation period. The present results are similar to those previously obtained for spring wheat. The short period of leaf activity is the chief factor limiting barley growth.

In der Arbeit wird eine Möglichkeit der Kombination von Humusstoffen mit mineralischen Nährstoffen und Substanzen mit fungiziden Eigenschaften beim Bespritzen von Pflanzen geprüft. Es wurde die fungizide Wirkung der Präparate Heryl, Novozir N, Sulka und Kuprikol, die mit Humusstoffen kombiniert worden sind, an Sclerotinia fructicola (WINT.) REHM., Alternaria brassicae (BERK.) SACC. und Erysiphe graminis var. tritici MARCHAL getestet. Es zeigte sich, dass Humusstoffe die Wirksamkeit der benutzten fungiziden Stoffe nicht herabsetzen. Beim Testen der Wirksamkeit von Novozir N von 0.5 bis 0.03% ist festgestellt worden, dass eine Zugabe von Humusstoffen die fungizide Wirkung des Präparates bis um 12% erhöht.
Weizen, der im Gewächshaus in Wasserkultur gezogen wurde und künstlich mit Erysiphe graminis var. tritici MARCHAL infiziert worden war, wurde während der Kultivierung wöchentlich mit einer kombinierten Lösung gespritzt, die Humusstoffe, Mineral-Nährstoffe, und Novozir N enthielt. Die Ergebnisse zeigen zweifache Wirksamkeit solcher kombinierter Lösungen: eine stimulierende Wirksamkeit der Huminsäuren mit der Mineralstofflösung auf das Wachstum des Weizens und eine fungizide Wirkung auf den parasitischen Pilz. Am allerwirksamsten erwiesen sich eine Doppelkombination von Novozir N mit Humusstoffen und von Novozir N mit Mineral-Nährstoffen. Bei Verwendung aller Kombinationen mit Novozir N konnte die Infektion der Blätter unterdrückt werden, während sie bei anderen Varianten bedeutend fortgeschritten war. Das Wurzelsystem reagierte empf indlich auf das Bespritzen der Weizenblättter.

Zwanzig neu synthetisierte Derivate der Phenoxyessigsäure VII-XXVI, die in der vorgehenden Arbeit (Makovcová, Vaculík 1963) bereits beschrieben worden sind, wurden mittels empfindlicherer Teste bei einer Konzentration von 10^-10 nochmals überprüft. Es wurde der Kressenwurzeltest und derTurfitt-Test mitSacharomyces cerevisiae benützt. Im Vergleich zur Wirkung von neun bekannten Wuchsstoffen Ia-VI unterschiedlicher Wirkungsweise zeigten die geprüften Substanzen weder eine Wirkung auf das Längenwachstum, noch auf die Zellteilung. Bei diesen Untersuchungen zeigte sich, dass die chemische Struktur selbst nicht immer massgebend für die Wirkungsweise ist. Bei den Substanzen, die von uns geprüft wurden, zeigte sich die Art und Zahl der Substituenten im aromatischen Kern für sehr wichtig. Die Resultate dieser Arbeit beweisen, dass der sonst sehr empfindlicheTurfitt-Test eine unge-eignete Methode zur Ermittlung der Wirkung von Wuchsstoffen des Typus 3-Indolylessigsäure (IIa) ist.

Im Rahmen des Versuches wurde der Einfluss des Alters der männlichen und weiblichen (maximal fünf Tage alten) Blüten auf das Geschlechtsverhältnis der Nachkommensehaft beiMelandrium album Garcke untersucht.
Es konnte festgestellt werden, dass der Prozentsatz an weibliche Pflanzen in der Nachkommenschaft zwei Tage alter, bestäubter weiblicher Blüten nachweisbar erhöht schien.
In der Nachkommenschaft bestäubter weiblicher Blüten, die älter als zwei Tage waren, äusserte sich im Auftreten weiblicher Individuen eine absinkende Tendenz.
Das Alter der männlichen Blüten hatte keinerlei Einfluss auf das Geschlechtsverhältnis der Nachkommenschaft.

5-Bromo-2'-deoxyuridine-2-¹⁴C was prepared from 5-bromouracil-2-¹⁴C and 2'-de-oxyguanosine using trans-N-deoxyribosylase fromLactobacillus helveticus and incorporated into DNA ofAllium cepa roots. After isolating the DNA and hydrolyzing it enzymatically to deoxynucleoside-5'-phosphates a radioactive nucleotide was detected which yielded 5-bromo-2'-deoxyuridine-2-¹⁴C on enzymatic dephosphorylation. The incorporation of 5-iodo-2'-deoxy-uridine-2-¹⁴C was followed only by microautoradiography.

Attempts to elucidate the physiological basis of cold-resistance during germination led to the investigation of the germination of seeds at low temperature, the effect of pathogenic and parasitic microorganisms being excluded.
At the various experimental temperatures (4°, 6°, 8°, 10° and 14°C) it was found that seed samples of different varieties of maize respond to conditions close to the temperature minimum for germination in three quantitatively different ways. Firstly, caryopses germinate considerably later than at higher temperatures, secondly, the kernels will not germinate even after a prolonged period, without losing their viability and, thirdly, in some of the caryopses the embryos perish.
The lower the temperature used the greater the inhibition of germination and the higher the mortality of the embryos. The increase in mortality with decreasing temperature indicates that the mortality is primarily due to the actual effect of the low temperature. Samples of seeds displayed quantitative difference in the above mentioned response.
Only when fungicide-treated seed material was used for the cold-resistance experiments was a significant relationship found to exist between this property and the general germinating capacity or mortality at the same low temperature.