1. Apoximis
1.1. Defined as asexual formation of seeds from the maternal tissues of the ovule from the mother plant
1.2. The production of viable seeds without pollination and germination
1.3. No meiotic division and fertilization of the gametes to form a zygote
1.4. Embryos develops from tissue other than zygote
1.5. Seeds can be generated from somatic cells (non-sexual cells/somatic cells)
1.6. Integument or nucellus cell undergo mitosis, producing an embryo/embryos
1.7. Situation known as polyembryony
2. SIMILARITIES BETWEEN APOMIXIS AND PARTHENOCARPY
2.1. No fertilization involved. So, both produce offsprings similar to parents.
2.2. There is no chance of diversity in genes
2.3. Used as asexual means or vegetative propagation methods. Both methods are asexual.
2.4. Still involve the sexual organs of the plant-the ovary and the ovules.
3. Parthenocarpy Fruit
3.1. What is Parthenocarpy
3.1.1. Development of fruit without fertilization of ovules
3.1.2. A seedless fruit that resembles a normal produced fruit
3.1.3. An artificial or natural production of fruits without fertilization
3.1.4. E.g Pineapple, Banana, Cucumber, Grape, Orange, Grapefruit
3.1.5. The word parthenocarpy comes from Greek, meaning "virgin fruit"
3.2. Types of Parthenocarpy
3.2.1. Vegetative parthenocarpy
3.2.1.1. Production of seedless fruits without fertilization
3.2.1.2. Plants that do not require pollination or other stimulation (hormones) to produce parthenocarpic fruit
3.2.1.3. E.g Pear and Fig
3.2.2. Stimulative parthenocarpy
3.2.2.1. A production of seedless fruits by applying various stimulation (hormones: auxin, gibberelin) to stop fertilization
3.2.2.2. A process where pollination is required but no fertilization takes place
3.2.2.3. occurs when
3.2.2.3.1. A wasp inserts (pollinator) its ovipositor (a tubular organ through which a female insect) into the ovary of a flower
3.2.2.3.2. Stimulated by blowing wind or growth hormones into the unisexual flowers found inside a structure called syconium (flask-shaped structure lined with unisexual flowers)
3.2.2.3.3. Diploid pollen grain gives a stimulus to the ovary when self pollinated (due to pollen hormones) E.g grapes and bananas
3.2.2.3.4. Pollination alone (not followed by fertilization) E.g watermelon)
3.2.3. Stenospermacarpy (artificial parthenocarpy)
3.2.3.1. Fertilization is followed by embryo (seed) abortion
3.2.3.2. Pollination triggers fruit development but ovules or embryos abort without producing mature seed
3.2.3.3. Produce seedless fruit but the seeds are actually aborted (premature) while they are still small
3.2.3.4. E.g Grapes (sprayed with Gibberellin to increase size of the fruit and to make fruit clusters less tightly packed)
3.3. Artificial parthenocarpy
3.3.1. Planth growth regulators has ability to induce parthenocarpy by plant hormones
3.3.1.1. Hormones auxins, gibberellins and cytokinin are well known to induce parthenocarpy
3.3.1.1.1. Hormone auxin - treatment of young, unpollinated ovaries in certain cultivars of strawberry, tomato, grape, orange
3.3.1.1.2. Hormone gibberellins - effective in producing seedless grapes and is the active component in preparations used to prevent premature dropping fruit
3.3.1.2. Stimulate with pollen
3.3.1.2.1. In certain plants, pollen are present incompatible with female flower
3.3.1.2.2. Pollen tube enters into an embryo sac through microphyle, but male gamete are not fertilize the egg cell
3.3.1.2.3. Pollen tube disappear, but it can stimulate the fruit
3.4. Benefits of parthenocarpy
3.4.1. Provides seedless fruits and improves quality
3.4.2. Reduces the complete cost of the cultivation
3.4.3. Improves crop yield without using organic pesticides
3.4.4. Plant growth regulators are natural and fruits produced is larger
3.5. Parthenogenesis
3.5.1. A component process of apomixis
3.5.1.1. Diploid parthenogenesis
3.5.1.1.1. To produce seed with 2n embryo
3.5.1.1.2. Causes by megaspore mother cell (2n)
3.5.1.1.3. Develops into embryo (2n) without fertilization
3.5.1.1.4. E.g Strawberry: embryo develops from nucellus cell (2n) and produce more seed
3.5.1.2. Haploid parthenogenesis
3.5.1.2.1. To produce seed with haploid (n) embryo
3.5.1.2.2. The development of an egg and become haploid embryo without fertilization
4. Development of Seeds
4.1. 3 basic parts : An embryo, the endosperm and a seed coat
4.2. Seed Structure
4.2.1. An Embryo
4.2.1.1. Radicle
4.2.1.1.1. The shoot of a plant that supports the cotyledons in the seed
4.2.1.1.2. The root of embryo
4.2.1.2. Plumule
4.2.1.2.1. Consisting of the apical meristem
4.2.1.2.2. The first true leaves of the young plant
4.2.1.3. Hypocotyl
4.2.1.3.1. The portion of embryo or seedling that lies between the root and cotyledons
4.2.1.3.2. Upon germination, the hypocotyl pushes the cotyledons above the ground to develop
4.2.2. The Endosperm
4.2.2.1. Cotyledon
4.2.2.1.1. Endosperm constitute a major portion of seed
4.2.2.1.2. Also known as Scutellum
4.2.2.1.3. Examples
4.2.3. 1. The process of seed development begins with double fertilization & involves the fusion of the egg and sperm nuclei into a zygote
4.2.4. Micropyle
4.2.4.1. Small pore on the seed coat for water absorbing to begin germination
4.2.4.2. The micropyle is near the funiculus (seed stalk) in angiosperm seeds
4.2.5. The Seed Coat
4.2.5.1. Seed Coat (Testa and Tegmen)
4.2.5.1.1. In dicots, the seed coat further divided into an outer coat, called testa and inner coat called tegmen
4.2.5.2. The hilum is the scar left when seed is detached from the funiculus
4.3. Seed Growth
4.3.1. Gymnosperms
4.3.1.1. 1. The two sperm cell transferred from the pollen do not develop seed by double fertilization, but one sperm nucleus unites with the egg nucleus and the other sperm is not used
4.3.1.2. 2. The ovules after fertilization develop into the seeds
4.3.1.3. 3. The seeds do not develop enclosed within an ovary but are usually born exposed on the surfaces of reproductive structures, such as cones
4.3.2. Angiosperms
4.3.2.1. 2. The second part of this process is the fusion of the polar nuclei with a second sperm cell nucleus, thus forming a primary endosperm
4.3.2.2. 3. After fertilization, the zygote is mostly inactive, but the primary endosperm divides rapidly to form the endosperm tissue
4.3.2.3. 4. The seed coat form from the two integuments or outer layers of cells of the ovule, which derive from tissue from the mother plant: the inner integument forms the tegmen and the outer forms the testa
5. DIFFERENCES BETWEEN PARTHENOCARPY AND APOMIXIS.
6. DIFFERENCES BETWEEN PARTHENOCARPY AND PARTHENOGENESIS
7. Development of Fruit
7.1. Flowers need to be pollinated and fertilized to create fruit
7.2. Some species of plants requires
7.2.1. Pollination & no fertilization
7.2.2. No pollination & no fertilization
7.3. Types of fruit development
7.3.1. True fruits
7.3.1.1. Fruits developed after fertilization
7.3.1.2. Ripened ovary grows into fruits
7.3.1.3. E.g Mango, Maize, Grape
7.3.2. False fruits/accessory fruits
7.3.2.1. Derived from foral parts other than ovary
7.3.2.2. E.g Peduncle in cashew nuts & thalamus in apple
7.3.3. Parthenocarpy fruits
7.3.3.1. Seedless fruits formed without fertilization
7.3.3.2. E.g Pineapple, banana, cucumber, orange
8. Types of Fruit
8.1. Aggregate Fruit
8.1.1. Developed from more than one carpel that fused together to form entire fruit
8.1.2. E.g Strawberry, blackberry, rasphberry
8.2. Accessory Fruit
8.2.1. Developed from ripened ovary but sometimes from another ovary of flower
8.2.2. False fruit
8.3. Simple Fruit
8.3.1. Dry Fruit
8.3.1.1. Not fleshy
8.3.1.1.1. Pericarp is not distinguished into three layers
8.3.1.2. Examples
8.3.1.2.1. Dehiscent fruit
8.3.1.2.2. Indehiscent fruit
8.3.1.2.3. Schzocarpic fruit
8.3.2. Succulent Fruit
8.3.2.1. Fleshy
8.3.2.2. Lomentum: Mimosa, Acacia arabica, Compound samara: Elm (Holoptelea), Maple, Cremocarp: Coriander
8.3.2.3. Indehiscent
8.3.2.4. Seeds are liberated after the decay of the flesh
8.3.2.4.1. Pericarp distinguished into epicarp, mesocarp and endocarp
8.3.2.5. Berry: tomato, grape, cranberry. banana, Pome: apple, pear Drupe: cherry, plum, peach
8.4. Multiple Fruit
8.4.1. Developed from cluster of flower
8.4.1.1. Sorosis
8.4.1.1.1. Fruits are derived from catkin, spike and spadix type of inflorescence
8.4.1.1.2. E.g Mulberry, Pineapple, Jackfruit
8.4.1.2. Syconus
8.4.1.2.1. Fruit develops from the hypanthodium type of inflorescence
8.4.1.2.2. E.g Pineapple, Fig