Original video: https://youtu.be/ThMioFleJe8
Delivered on: 24 April 2024
This video covers two key aspects of plant physiology:
1. Plant Mineral Nutrition: Explore the essential role of macronutrients in plant growth, including classification, deficiency symptoms, and the concept of nutrient synergism and antagonism.
2. Seed Viability Testing: Learn about the factors affecting seed germination, including water, oxygen, and temperature. Discover the concept of seed dormancy and explore the tetrazolium test, a rapid method for assessing seed viability.
Watch part 2 seed viability: https://youtu.be/9Syp_CYHS3s
This video provides valuable insights into plant nutrition, seed biology, and essential laboratory techniques for students of plant physiology and related fields including:
Mineral and nutritional root uptake
Mineral macronutrients
Classifying mineral nutrients
Nutrient deficiency vs sufficiency
Patterns of deficiency
Mulder's Chart - Synergism and Antagonism
The food for the germinating seedling may be stored in part of the embryo itself, such as the fleshy cotyledons of a bean seed, or it may take other forms, including endosperm, which is a special starch-rich storage tissue that surrounds the embryo. A seed is officially considered to have germinated when the young root, called the radicle, emerges from the seed coat. To germinate, a seed requires three things – water, oxygen, and a suitable temperature. Water uptake, also called imbibition, is the first stage of seed germination. During this process the dry seed, which typically has a water content of less than 10%, absorbs water and swells. This process serves to hydrate the dry components of the seed and active the metabolic machinery necessary for germination. Among the early metabolic activities occurring in the seed is the breakdown of starches stored in the seed into simple sugars that can be used for energy and building blocks for necessary cellular structures. A seed that has not germinated because it is lacking one or more of the necessary requirements for germination is termed quiescent. These seeds are simply "resting", waiting for the appropriate conditions for germination. Given water, oxygen and/or a suitable temperature, a quiescent seed will germinate. However, even if given the proper conditions, a seed may not germinate. These seeds may fail to germinate because the seed is either dormant or "dead". Dormant seeds have the potential to germinate, but are prevented from doing so by some mechanism. Thus, even though all the proper growth conditions are present, they don't germinate unless they have been "primed" and their dormancy mechanism has been overcome. There are many dormancy mechanisms in seeds.
The purpose of laboratory testing of seed germination is to assess seed quality or viability and to predict performance of the seed and seedling in the field. Several different kinds of testing are available depending on the type of seed to be tested, the conditions of the test, and the potential uses of the seed.
Germination percentage is a good measurement of seed viability. One disadvantage of conventional germination tests is that they require a waiting period of two weeks or more. The tetrazolium test (TZ- test) is a quick chemical test that can be conducted in a short period of time with minimal equipment. In this test, a seed is incubated in a dilute (0.1%) solution of 2,3,5-triphenyltetrazolium chloride. Initially, the TZ solution is colorless, but changes to read (Triphenyl formaza) when it comes into contact with hydrogen (reduction) derived from enzymes in the respiration process.
Embryos showing active respiration are considered ‘viable’ and turn red. The darker color the greater the respiratory activity in the seed. Light pink color indicates a seed with reduced viability when compared to a seed that stains dark red.
Keywords: Crop Physiology, Plant Nutrition, Mineral Nutrition, Macronutrients, Micronutrients, Seed Viability, Seed Germination, Tetrazolium Test, Seed Dormancy, Plant Growth, Plant Development, Plant Science, Agriculture
Location:
Faculty of Agriculture, Universiti Putra Malaysia
Fakulti Pertanian, Universiti Putra Malaysia, 43000 Seri Kembangan, Selangor
XPMM+9J Seri Kembangan, Selangor
2.9845517506267742, 101.73803356324866
Attribution 4.0 International — CC BY 4.0 - Creative Commons
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