CS211385B2 - Method of sterilization of the male insects - Google Patents

Abstract

A method for selectively sterilizing male anthers crops, in particular small grains), wherein the plants are treated with a heterocyclic compound of formula wherein R is hydrogen, alkali metal or alkaline earth metal, ammonium, alkylammonium, the alkyl or alkyls of which contain not more than 6 carbon atoms, or alkyl with not more than 10 carbon atoms or, where appropriate, which, as active substance, is contains the compound. The plants are treated in growth status between late harvesting and the appearance of the ear. Used for treatment doses of 0.05 to 2.0 kg / ha. Where applicable the mixtures contain the active ingredients 50 to 1500 ppm.

Description

The invention relates to a method of sterilizing male anthers of plants, in particular cereal plants.

In order to obtain high-yield hybrid seeds, breeders carry out cross-pollination of seeds of carefully selected parent plants, an operation that is time-consuming and requires highly specialized staff, especially in the case of small grain cereals that have hermaphrodite flowers and usually self-pollinate. Generally speaking, small grain cereal hybrids can only be obtained if self-pollination is completely prevented and in practice this is achieved by manually removing male anthers from the cereal flowers. Accordingly, if the flowers could be treated in such a way that male anthers were sterilized without affecting female fertility, this would mean considerable progress in seed breeding.

We have now found a group of heterocyclic compounds which, when applied to plants and especially small grain cereals, selectively sterilize male anthers.

The invention provides a method of sterilizing male anthers of plants by treating the plants with a heterocyclic compound of formula I,

Sr ^ cooR

AND

Η (I) in which

R is hydrogen, alkali metal, alkaline earth metal, ammonium, alkylammonium, the alkyl group (s) of which preferably contain at most 6 carbon atoms, or alkyl of 10 carbon atoms, preferably up to 4 carbon atoms, in their growth stage between late offshoot and the appearance of a spike, either with a dose of a compound of the above formula I of 0.05 to 2.0 kg / ha, or with a composition (mixture) containing 50 to 1500 ppm of a compound of the above formula I

When R is a metal ion, it is preferably sodium or potassium, but other metal ions can be used if desired.

The process according to the invention advantageously treats small-grain cereals with a compound of the formula I in which R represents hydrogen, an alkali metal, an alkaline earth metal, ammonium, alkyl ammonium of alkyl or alkyl having at most 6 carbon atoms or alkyl of at most 10 carbon atoms , preferably at most 4 carbon atoms.

In particular, cereal plants are treated with 2-carboxy-3,4-methane-pyrrolidine or 2-methoxycarbonyl-3,4-methane-pyrrolidine.

Heterocyclic compounds can be applied to plants at various stages of their development, suitably during the period between the second node of the plant and just before the discovery of the ear, i.e. during the plant growth period. After application at this time, the male anthers are substantially sterilized.

The sc compounds are preferably applied to small grain cereals such as wheat, barley, oats, rye, rice and millet, but can also be applied to large grain cereals such as corn and sorghum.

The compounds may be applied to plants as such, but, as is common practice in the application of chemicals to plants, it is preferable to apply the compound in the form of a mixture which includes, in addition to the compound, a carrier or surfactant.

It has also been found that when the heterocyclic compound of formula (I) is applied as a sterilizing agent, it can also inhibit the vegetative growth of the plants so treated. For example, a distinct reduction in wheat elongation has been observed after treatment of wheat plants with the compounds of the invention of formula I. This phenomenon has been observed in other cereals as well as in legumes such as flaxseed, mustard, sugar beet and soybean. It is clear that suppressing the vegetative growth of cereals at the right stage of their development can be very beneficial. For example, when grain is exposed to different climatic conditions and changes, it becomes less sensitive to it.

Achieving sterilization of male anthers as well as vegetative growth by applying only one chemical compound can be very useful.

The dosage of the heterocyclic compound applied to the plants to induce male sterility may be varied within wide ranges, but efficacious results in cereals were achieved using rates ranging from 0.05 kg / ha to · 2.00 kg / ha. Mixtures containing 50 to 1500 ppm of a heterocyclic compound are very suitable for this purpose. Growth suppression can suitably be achieved by applying rates ranging from 0.05 kg / ha to 8.00 kg / ha; successful results have been achieved with doses ranging from 0.1 kg / ha to 2 kg / ha.

By the term "carrier" as used herein is meant a material, which may be of inorganic, organic- and synthetic or natural origin, with which the active compound is mixed or transformed in a form to facilitate application to a plant, seed, soil and other object which to be treated, or for storage, transport or handling. The carrier may be in solid or liquid form. One of the materials commonly used in the manufacture of herbicide dosage forms can be used as the carrier.

Suitable solid carriers are natural and synthetic clays and silicates, for example natural silicas, such as diatomaceous earths; magnesium silicates, for example talc; magnesium aluminum silicates such as attapulgites and vermiculites; aluminum silicates such as kaolites, montmorillonites and mica; calcium carbonates, calcium sulfate; synthetic hydrated silicon oxides and synthetic calcium or aluminum silicates; elements such as carbon and sulfur; natural and synthetic resins such as coumarone resins, polyvinyl chloride and styrene polymers with copolymers; solid polychlorinated phenols; resins, waxes such as beeswax, paraffin wax and chlorinated mineral waxes; and solid fertilizers such as superphosphates.

Examples of suitable liquid carriers are water, alcohols, for example isopropyl alcohol, glycols; ketones, for example acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ethers, aromatic hydrocarbons such as benzene, toluene and xylene; petroleum fractions, for example kerosene, light mineral oils; chlorinated hydrocarbons such as carbon tetrachloride, perchlorethylene, trichloroethane, including liquefied gaseous compounds. Mixtures of different fluids are often suitable.

The surfactant may be an emulsifying agent, a dispersing agent or a wetting agent; it may be nonionic; or ionic character. One of the surfactants commonly used in the manufacture of herbicide or insecticide dosage forms may be used. Examples of suitable surfactants are the sodium or calcium salts of polyacrylic acids and ligninsulfonic acids; condensation products of fatty acids or aliphatic amines or amides with at least 12 carbon atoms per molecule with ethylene oxide and / or propylene oxide; sulfates or sulfonates of these; condensation products, alkali metal or alkaline earth metal salts, preferably sodium salts, sulfuric or sulphonic acid esters containing at least 10 carbon atoms per molecule, for example sodium lauryl sulphate, secondary sodium alkyl sulphates, sodium sulphonated castor oil and sodium alkylarylsulphonates such as sodium dodecylbenzene sulphonate; ethylene oxide polymers; and ethylene oxide-propylene oxide copolymers.

The compositions of the invention may be converted into wettable powders, dusts, granules, solutions, emulsified concentrates and aerosols. Wettable powders usually contain about 25 to 50 or 70% of toxicant and usually contain, moreover, a solid carrier, 3-10% w of dispersing 'agent and optionally 0 to 10 o / _o stabilizer (s) and / or other additives such as penetrants or stickers . Dusts are elbicitously in the form of similar concentrates; compositions such as wettable powders, but without dispersing agents, and are diluted in the field with another solid carrier to a mixture containing usually 0.5-10% w / w. toxic components. The granules are usually prepared in sizes of 10 and 100 BS mesh and can be produced by agglomeration or impregnation technology. The granules usually contain 0.5 to 25% by weight of toxic components with 0 to 10% additives such as stabilizers, retardants and binders. Emulsified concentrates generally contain additionally solvent ¹ and, if necessary, additional solvent, 10 to 50% w / v, toxic components, 2 to 20% w / v. emulsifiers and 0-20% w / v. appropriate additives such as penetration stabilizers and corrosion inhibitors. Suspension concentrates are formulated to contain a stable, non-sedimenting flowing product and typically contain from about 10% to about 75% toxic component, from about 0% to about 15% dispersants, from about 0.1% to about 10% suspending agents such as protective colloids and thixotropic agents; 0 to 10% suitable additives such as; antifoam agents, corrosion inhibitors, stabilizers, penetration agents and adhesives and, as a carrier, water or an organic liquid in which the toxic substance is practically insoluble; some organic solids or inorganic salts may be dissolved in a carrier to prevent sedimentation or as antifreeze agents.

The composition according to the invention may also contain other components, for example protective colloids, such as gelatin, glue, casein, gums, cellulose ethers and polyvinyl alcohol; thixotropic agents such as bentonites, sodium polyphosphoric acid; stabilizers such as ethylenediaminotetraacetic acid, urea, triphenyl phosphate, other herbicides or pesticides; binders such as non-volatile oils.

Aqueous dispersions and emulsions, for example mixtures obtained by diluting a wettable powder or an emulsified concentrate with water, are also within the scope of this invention. Said emulsions may be of the water-in-oil or oil-in-water type and have a thick "mayonnaise" consistency.

The invention is further explained in the following examples, whose terminology describing the stages of growth during the development of grain plants corresponds to "Plant Pathology", Volume 3, 1954.

The tests were carried out with 2-methoxycarbonyl-3,4-methanpyrrolidine, hereinafter referred to as the sterilizing agent, on spring wheat plants of the "Calibri" variety.

The sterilizing agent was; applied in two stages of plant development, namely; at:

Stage 7: Stage of the second knee, ie just before the ear becomes recognizable as a separate organ;

stage 10: the middle cusp stage, ie the stage where the cob is formed and is visible as a bulge in the surrounding leaf scabbard.

Groups of plants (20 pots, 3 pots each) at development stages 7 and 10 were sprayed with 100 ppm or 500 ppm sterilizing agent solutions in water with the addition of a wetting agent (Triton C-155, 0.1% concentration). Control experiments were also carried out on plants treated only with water and a wetting agent. When the ear is discovered, a translucent bag is placed over the ear to prevent cross-pollination from untreated ears. Wheat plants are allowed to develop grains; the average number of wheat grains per cluster is evaluated, the results of which are given in Table I.

The attempt number

Table I

Sterilizing agent concentration (ppm)

Average number of grains / ear after treatment of wheat plants at stage 7 of stage 10

Untreated control plants 1 2 3

- 36.3 36.3 0 34.3 32.8 100 ALIGN! 3.4 0.5 500 0 0

From the experiments it can be seen that the sterilizing agent induces almost complete sterility at 100 ppm and perfect sterility at 500 ppm. Comparable results were observed in field trials.

In order to demonstrate that female fertility was not substantially impaired, male sterile plants were cross-pollinated with viable pollen. The seeds obtained from this cross-pollination were germinated and the germination results determined that the seed was ~ 100% viable.

Example 2

Tests with 2-carboxy-3,4-methanpyrrolidine were carried out on wheat plants of the Dove variety.

The compound was applied to plants in 2 stages of plant development during the period of plant stem extension before the appearance of the ear, in:

Stage 8: if the last leaf is just visible;

Stage 9: if the tongue (11gula) of the last leaf is just visible.

Groups of plants (20 pots, 3 pots each) at development stages 8 and 9 were sprayed with 72 ppm and 144 ppm solutions of water and wetting agent (Nonidet P-40; concentration 0.1%). Control experiments were also carried out in which the plants were treated only with water and a wetting agent. When the ear appeared, a translucent sachet was placed over the ears to prevent cross-pollination from untreated ears. Wheat plants were allowed to develop seeds; the average number of wheat grains in the ear was evaluated; the results of this evaluation are set out in Table II below.

The attempt number

TABLE II

Sterilizing agent concentration (ppm)

The average number of grains in the ear after treatment of wheat plants at stage 7 of stage 10

Untreated control plants -

0

72

144

These results clearly demonstrate the sterility of male anthers, and female viability was confirmed intact in subsequent cross-pollination tests.

Example 3

The tests were performed with 2-carboxy-3,4-me36.3 36.3

34.3 32.8

0

0 thanpyrrolidine on spring barley variety Imber.

The sterilizing agent was applied to plants at development stages 8 and 9 as described in the previous examples, except that the sterilizing agent was applied in the form of a 100 and 200 ppm solution in water. The results are given in Table III below.

The attempt number

TABLE III

Sterilizing agent concentration (ppm)

The average number of grains in the ear after treatment of wheat plants in stage 8 stage 9

Untreated Control 1 2 - 21.2 21.2

100 0.25 16.25

200 0 7.95

The results clearly demonstrate the sterilizing effect of 2-carboxy-3,4-methane-pyrrolidine on barley.

Example 4

Tests with 2-carboxy-3,5-methanpyrrolidine were performed on Sappo spring wheat.

Groups of plants (10 pots and 2 pots) in development stages 8 and 9/10 were sprayed with a sterilizing agent in the form of a 50 or 100 ppm solution in water with added wetting agent (Nonidet P-40; concentration 0.1%). Control tests were also performed by treating the plants with only water or a wetting agent. When the ear appeared, a translucent bag was placed on the ears to prevent cross-pollination by untreated plants. Wheat plants were allowed to develop seeds and the average number of wheat grains was evaluated; the results of these evaluations are given in Table IV below.

The attempt number

TABLE IV

Sterilizing agent concentration (ppm)

The average number of grains in the ear after treatment of wheat plants in Stage 8 Stage 9/10

Untreated control plants

100 ALIGN!

41.6

4.1

0.1

41.6

38.9

22.1

Example 5

Prior to harvesting the ears of wheat plants used in the experiment in Example 1, the height of the randomly selected stalks of stage 7 treated wheat plants was compared with the height of 10 control stalks of untreated plants by measuring the distance between the ear node and the ear base. The results are given in Table V below.

TABLE V

Sterilization Concentration Average Stalk Length (cm.) Reduction in% Reagent Length (ppm)

Control 50 33.4 26.0 22.0 100 ALIGN! 25.4 24.0 200 23.8 28.7

The results clearly show that the stalk length of wheat plants treated with 2-methoxycarbonyl-3,4-methanopyrrolidine is noticeably reduced compared to untreated plants.

Example 6

Suppression of vegetative growth was also observed when a larger number of cereal plants and non-cereal plants were treated with 2-carboxy-3,4-methano-pyrrolidine at a dose of 0.2 and 1 kg / ha, respectively. Suppression of vegetative! Growth was assessed visually on a scale of 0 to 8, with a value of 0 indicating that growth was not suppressed, and a value of 8 indicating significant growth suppression without sacrificing the plants. The results of foliar spraying are given in Table VI below.

TABLE VI

Corn rate (kg / ha)

Rice hedgehog Oats skin foot

Linseed Mustard Diabetes Soybean Seed

15 5

0.2 0 2 2

5 7 8

3 5 8

Example 7 Boxes with 3,4-methane-pyrrolidine (treated with

10 plants), as shown in the following Effect on suppressing the growth of the pereneal rye bulka VII. was evaluated by spraying 2-car- TABLE VII Rate (kg / ha) Growth of offshoots Height (cm) Fresh matter (gj 0 control 18 31 14 0.5 15 Dec 30 15 Dec 2,0 20 May 23 12 5.0 17 19 Dec 10 The results clearly demonstrate distinct printing- Example 8 height and no adverse effect on the cutting, which is useful in influencing Experiments similar to experiments were performed growth of grass. described in Example 7 with soybean varieties “Amsoy, before before the flowers appeared. After- dose used and the observed stalk heights are given in Table VIII below. TABLE VIII Dose Height (cm) after spraying (weeks) Height increase (cm) (kg / ha) 1 2 3 over the test period 0 (control) 51 87 90 54 0.5 39 39 39 2 1.0 36 36 37 3 It was observed again a clear reduction height of plant stems. During the trial- period was not observed flowering. SUBJECT OF THE INVENTION

A method of sterilizing male anthers in a

Claims (3)

A method for sterilizing male anthers in plants, characterized in that the plants are treated with a heterocyclic compound of formula I, wherein: R stands for hydrogen, alkali metal, alkaline earth metal, ammonium, alkylammonium, whose alkyl or alkyl alkyls contain no more than 6 carbon atoms, or alkyls of no more than 10 carbon atoms, in their growth stage between late offshoot and spike, either dose of a compound of the above formula I 0.05 to 2.0 kg / ha, or mixtures containing 50 to 1500 ppm of a compound of the above formula I. 2. A process according to claim 1, wherein the small grain cereal is treated with a compound of formula (I) wherein R is hydrogen, an alkali metal, an alkaline earth metal, ammonium, alkyl ammonium of alkyl or alkyl having at most 6 carbon atoms, or 10 carbon atoms, preferably up to 4 carbon atoms. 3. A process according to claim 1, wherein the cereal plants are treated with 2-carboxy-3,4-methano-pyrrolidine or 2-methoxycarbonyl-3,4-methano-pyrrolidine.