Some people with chest pain have normal or minimal narrowing of heart arteries; in these patients, vasospasm is a more likely cause for the pain, sometimes in the context of Prinzmetal's angina and syndrome X.
You are here. Pure Live Seed. Pure live seed (PLS) is a measure used by the seed industry to describe the percentage of a quantity of seed that will germinate. PLS is obtained by multiplying the purity percentage by the percentage of total viable seed, then dividing by 100.
What is a seed?  A seed is the product of plant fertilization.  It is the vessel in which combined genetic material from both  parent plants (in the case of cross-pollination) or singleâ¦ parent  plant (in the case of self-pollination) is carried to the next  generation.