Regardless of what you call it, a seed is an undeveloped plant embryo enclosed in a protective outer covering. It can be a husk or tuber, or anything that can be sown.
Genetic control of the growth and development
Plants require precise control of their genes and metabolites to regulate growth and development. These processes are controlled by complex pathways that are heritable and respond to environmental conditions. Molecular markers allow researchers to study the genetic control of traits. In this article, we will discuss how to identify molecular markers for plant breeding.
Seeds play a crucial role in the plant’s reproductive success. They store carbon and sulfur, and also contain specialized metabolites. The size of a seed is determined by the product of its growth rate and the time it takes to fill the seed.
Endosperm plays an important role in regulating the size and mass of seeds. A variety of genes control endosperm growth. Among the genes are leucine-rich repeat kinases (LRKs), which regulate the size and weight of the seeds. Another gene is the EXS/EMS1 gene, which encodes a protein that is involved in seed formation.
Chromatin remodelers are key proteins that modify nucleotides within DNA strands. Chromatin remodelers are critical for correct plant growth. Chromatin remodelers are important for the initiation of organ founder cells, such as root apical meristems.
The germination percentage of seed is an important indicator of its viability. Seeds can be counted as germinated when a radicle protrudes through the seed coat.
Seeds can be classified into two groups: those that germinate at a speed of less than 50% in a single day and those that germinate at a speed of more than 50% in a single day. Germination rates vary widely, depending on the variety and weather conditions. Some species germinate at a rate of 90% or more. Others germinate at a rate of less than 5%.
Several species germinate more quickly in cold temperatures, while others germinate more slowly. This is because of the physiological stress of cold. It is thought that the permeability of the seed coats is reduced by cold. Therefore, seeds that have been exposed to cold may not be able to germinate at a later, warmer temperature.
Physiological stress reduces the vigor of many plants, decreasing their germination rate and yield. In this study, we evaluated the effect of various stress factors on the germination rate of seed.
The dormancy of seed is the state in which seeds are unable to germinate under normal environmental conditions. This condition is influenced by different factors, including genetics, hormones, environmental signals and seed coats.
It is believed that dormancy promotes the storage of N-rich compounds in the seed, which enhances its viability. However, this phenomenon may not be uniform among species. Therefore, different methods are used to break dormancy in seed.
Seed dormancy is classified into two main groups: endogenous dormancy and chemical dormancy. Chemical dormancy is produced by various methods, such as deactivation of growth regulators. These inhibitors may be found in the endosperm of Iris, the embryo in Xanthium, or the cells in the seed.
Several plant species have physical dormancy. This occurs when the seed coat is too tough for the embryo to expand. A hard seed coat can weaken by scarification, abrasion or hot water. Hydraulic pressure and passage through the digestive tract of animals also weaken the seed coat.
Shape of the ovules
The shape of the ovules of a seed is an essential agronomic characteristic that affects the number of seeds in the fruit, which in turn determines the yield of the fruit. In many flowering plants, the nucellus, which is the ovule’s outermost compartment, remains after fertilization. It serves as an important source of reproductive cells.
Outer ovule integument development requires precise regulation of cell division and differentiation. However, Arabidopsis research has opened new avenues for identifying and understanding these processes.
Arabidopsis outer ovule integument consists of a two-cell layered structure. It grows around the developing embryo and develops into the outer layer of the seed coat. This simple, yet highly differentiated structure is a good model system to study basic principles of plant organ morphogenesis.
Ovule development is asymmetrical and is based on a complex interaction between phytohormones and signaling networks. Cell division and elongation are sensitive to this interaction. These processes are controlled by cytokinins, which are essential for the physiological functions of plant tissue.