Seeds are an important part of plant biology. They allow plants to reproduce and spread to new areas.
Seeds are also an important food source for humans and animals. They can be eaten whole or used to make oil, flour, and other products.
Functions
Seeds are the reproductive organs of flowering plants (angiosperms). A typical seed contains three main parts: the embryo, endosperm and a protective layer called the seed coat.
The embryo is a tiny, underdeveloped plant that will grow and mature into a new plant once it emerges from the seed. The endosperm stores food for the embryo to help it grow.
Seeds are also good sources of protein, which is important for growth and development. Some seeds are high in fiber, which can help reduce digestive issues like bloating and constipation.
Size
Grape seeds are a good source of vitamin C, which is important for improving the health of the heart and blood vessels. The seeds also contain flavonoids, which are a type of antioxidant that helps fight against cancer and other diseases.
In plants, seed size is thought to evolve in a trade-off between fitness and number (Smith & Fretwell, 1974). This is typically modelled from the parental point of view, and selection on seed size is influenced by the allocation cost to the mother plant of increasing seed size.
Shape
Seed shape can be influenced by many factors including dispersal, germination, and growth. For example, rounded seeds of cabbage species tend to roll into crevices and reticulate seeds of lamb’s quarters (Chenopodium album) often stay in positions where they first fall.
Moreover, seed shape is also affected by environmental conditions. The rounded seeds of many herbaceous grasses, for example, drop into the soil clod. The reticulate ones of the ferns and legumes, on the other hand, tend to remain in their original position.
The morphology of seeds can be described by geometrical figures such as the oval, ellipse, and cardioid, which can provide a quantitative description of seed shape, allowing the comparison between genotypes or seeds grown in different environments. These figures have been used to describe and quantify the shape of seeds in several model plants, such as Arabidopsis thaliana, Medicago truncatula, and Lotus japonicus, among others.
Appendages
The seeds of Salix and Populus (Salicaceae) are characterized by numerous long hairs which loosely accompany the seeds. Moreover, they have another unique annular appendage at the radical end of the seed that separates from the funiculus and easily breaks away from the seed.
In the study of Steyn et al [17], this small appendage was called a “hilar aril”. However, these observations only focused on the morphology and detailed structure of this structure in one African willow species Salix mucronata.
In the present study, we have used standard techniques for plant anatomy and histochemistry to investigate the whole ontogeny and detailed structures of the two seed appendages in Chinese willow S. matsudana, with the aim of showing how they are initiated and how they complete their development, especially to establish the correlation between their development and the development of the ovules.
Dispersal
The dispersal of seeds is a process that helps plants grow and reproduce. Seeds are transported in a variety of modes, including wind, water and animals.
Some plant species enclose their seeds inside fleshy fruits that are attractive to hungry animals. These fruit-loving animals are called frugivores, and they disperse seeds by eating the fruit and passing them through their digestive system.
This ingestion of the fruit pulp can improve germination rates by giving seeds a dose of nitrogen that helps fuel growth, and it also allows them to survive better after being digested. However, this strategy can be hampered by other factors, such as invertebrate predators or fungal infections.
