The invention provides methods for producing seeds in watermelon. In one embodiment methods are provided comprising grafting of a seed parent onto a stress tolerant rootstock, pollinating the seed parent with pollen from a pollen donor, and cultivating the seed parent until seed is formed. In specific embodiments, triploid seeds produced by a method of the invention are rendered conspicuously distinguishable from tetraploid seeds, and thus readily selected manually or by an automated machine. Methods for increasing seed yield and/or quality are also provided.

The invention provides methods for producing seeds in watermelon. In one embodiment methods are provided comprising grafting of a seed parent onto a stress tolerant rootstock, pollinating the seed parent with pollen from a pollen donor, and cultivating the seed parent until seed is formed. In specific embodiments, triploid seeds produced by a method of the invention are rendered conspicuously distinguishable from tetraploid seeds, and thus readily selected manually or by an automated machine. Methods for increasing seed yield and/or quality are also provided.

A method for producing haploid Lolium plants may start with providing a Lolium multiflorum inducer line, the L. multiflorum inducer line having the ability to induce mitotic genome instability and haploid sectoring when hybridized as a maternal parent with a Lolium sp. paternal parent, such as previously disclosed lines IL1 and IL2. The inducer line may then be crossed with a Lolium sp. to generate F1 plants, and the F1 plants may be self-fertilized so as to recover seed from the selfed plant. The recovered seed may then be planted to generate one or more F2 plants, and at least one of the F2 plants may be a haploid Lolium plant.

A method for producing haploid Lolium plants may start with providing a Lolium multiflorum inducer line, the L. multiflorum inducer line having the ability to induce mitotic genome instability and haploid sectoring when hybridized as a maternal parent with a Lolium sp. paternal parent, such as previously disclosed lines IL1 and IL2. The inducer line may then be crossed with a Lolium sp. to generate F1 plants, and the F1 plants may be self-fertilized so as to recover seed from the selfed plant. The recovered seed may then be planted to generate one or more F2 plants, and at least one of the F2 plants may be a haploid Lolium plant.

The present invention relates to the provision of technical means such as nucleic acids which, after transcription or after expression in a plant, are suitable for mediating the property of a haploid inductor or for increasing the induction capability of a haploid inductor, as well as methods and uses for the production and identification of non-transgenic and transgenic plant haploid inductors, as well as the improvement of existing plant haploid inductors.

The present invention relates to the provision of technical means such as nucleic acids which, after transcription or after expression in a plant, are suitable for mediating the property of a haploid inductor or for increasing the induction capability of a haploid inductor, as well as methods and uses for the production and identification of non-transgenic and transgenic plant haploid inductors, as well as the improvement of existing plant haploid inductors.

Provided herein are delivery methods of a plant treatment agent to a tissue of a plant, wherein the tissue is contacted with a plant treatment agent and delivery is aided by a centrifugal force applied to the plant. Disclosed herein is the discovery that drastic improvements in treatment delivery occur when plants are centrifuged after being contacted, submerged, unsubmerged, soaked, etc. in a solution containing a plant treatment agent. In one embodiment, haploid plants contacted with a colchicine solution are centrifuged to reveal improved chromosomal doubling rates as compared to control plants.

Provided herein are delivery methods of a plant treatment agent to a tissue of a plant, wherein the tissue is contacted with a plant treatment agent and delivery is aided by a centrifugal force applied to the plant. Disclosed herein is the discovery that drastic improvements in treatment delivery occur when plants are centrifuged after being contacted, submerged, unsubmerged, soaked, etc. in a solution containing a plant treatment agent. In one embodiment, haploid plants contacted with a colchicine solution are centrifuged to reveal improved chromosomal doubling rates as compared to control plants.

Disclosed are methods for the doubling of a plant cell's chromosome by applying an electromagnetic field and methods for obtaining a doubled-haploid plant cell. In some embodiments, the plant cell is selected from the group comprising maize, rice, tomato, and tobacco. Also disclosed is an apparatus for applying an electromagnetic field to a plant cell.

Disclosed are methods for the doubling of a plant cell's chromosome by applying an electromagnetic field and methods for obtaining a doubled-haploid plant cell. In some embodiments, the plant cell is selected from the group comprising maize, rice, tomato, and tobacco. Also disclosed is an apparatus for applying an electromagnetic field to a plant cell.