A seed is the embryonic stage of a plant’s life cycle. It is surrounded by a protective coating called the seed coat.
Seeds are essential for plant survival, and they serve several important functions. These include nourishment, dispersal, and dormancy during unfavorable conditions.
The seed is the product of the ripened ovule of gymnosperms (flowering plants) and angiosperms. This small embryonic plant is surrounded by a protective coat called the seed coat and may contain an endosperm.
The development of the seed in higher plants depends on processes of sexual reproduction. In seed plants, fertilization requires a viable pollen grain and a receptive stigma to produce a zygote.
Once the zygote develops, it forms a seed coat around the ovule and grows within the mother plant to a certain size before growth is halted.
The seed program is one of the key evolutionary innovations that allowed the gymnosperms and angiosperms to dominate terrestrial environments. It enables dispersal of species over wide areas and provides a source of food for animals in a long-term storable form.
Seeds serve several key functions for the plants that produce them. These include nourishment of the embryo, dispersal to a new location and dormancy during unfavorable conditions.
Most seeds are composed of three parts: the seed coat, endosperm and embryo. The seed coat is a protective covering that helps the seed to remain viable.
It also protects the embryo from physical, mechanical, temperature-related and water damage. It also serves as a channel to transmit environmental cues to the interior of the seed.
The outer seed coat varies from thin and papery to rock-hard. Inside the seed is the embryo plant and usually some sort of nutritive tissue called endosperm, which stores food. There are also accessory structures attached to the seed, including cotyledons, which are leaves that can hold a food supply for the growing sprouting seedling.
In botany, a seed is an undeveloped plant embryo and store of food enclosed in a protective outer covering. It is the product of a mature ovule in gymnosperm and angiosperm plants, following fertilization by pollen.
A seed has two layers, the outer layer known as the testa and the inner layer known as tegmen (see figure 126.96.36.199.1). The testa is thick and protects the ovule from moisture and sunlight.
The inner tegmen separates the embryo and endosperm tissue by a proteinous membrane called the aleurone layer. The embryo may be small (as in buttercups), or it may fill the entire seed as in roses and some mustards.
The developing seed consists of an embryo, which is linear with one or more seed leaves or cotyledons (one in flowering plants, several in Pinus and other gymnosperms), a radicle, and a hypocotyl. The radicle and plumule are covered with sheath-like structures called coleoptile and coleorhiza.
The seed size and number of a plant are among the most important life-history traits for both its fitness and yield. Thus, understanding the genetic architecture of these traits is critical to both conservation and agroforestry.
In this study, we mapped quantitative trait loci (QTLs) that affect 12 life history traits related to seed size and fruit size. We identified eight QTL on chromosomes 1, 3, 4, and 5, with the largest located at the bottom of chromosome 1 (
The QTL affecting seed number colocated with QTLs for other traits, suggesting that it controls seed size via maternal components affecting ovule number or carpel development, or reproductive resource allocation in the mother plant. The remaining six putative QTL did not explain any of the phenotypic variation in seed number.