CORVALLIS, Ore. (KOIN) – Researchers at Oregon State University have found seeds that germinate in an amber-coated pine cone.
According to the university, the phenomenon is caused by a rare botanical condition called premature germination, in which the seeds germinate before leaving the fruit.
George Poinar Jr. of Oregon State College of Science published an article in Historical Biology describing a pine cone about 40 million years old, enclosed in a Baltic amber with several embryonic stems.
“Crucial to the development of all plants is that the seeds typically germinate in the soil after the seed has fallen,” Poinar said. “We tend to associate liveliness – the development of the embryo even within the parent – with the animals and forget that it sometimes occurs in plants.”
He added that most typically these events are related to cup seeds. They provide, indirectly or indirectly, most of the food eaten by humans, flowering and producing seeds inside the fruit.
“Seed germination in fruit is quite common in plants that lack seed dormancy, such as tomatoes, peppers and grapefruit, and it occurs for a number of reasons,” Poinar said. “But it’s rare in the seeds of power.”
According to the university, gymnosperms – like conifers – produce “bare” or unsealed seeds.
Early germination of pine cones is so rare, Poinar said that only one naturally occurring example of this condition from 1965 has been described in the scientific literature.
“That’s part of what makes this discovery so fascinating, even in addition to being the first fossil record of plant vitality involving seed germination,” he noted. “I find it fascinating that the seeds of this little cone can begin to germinate inside the cone and the shoots can grow so far before they are destroyed in the resin.”
Poinar said there are needle clusters at the top of the sprouts, some of which are five bundles. This links the extinction of the fossil to the extinct Pinus cembrifolia, previously described from the Baltic amber.
No cones in the Baltic amber are usually found, he added.
“Collectors appreciate those who appear, and because the scales of the cones are hard, they are usually very well preserved and look real,” the university says.
Plant viability typically occurs in two ways, but early germination is the most common of the two, Poinar explained, for example, when an onion rises directly from the flower head of a parent plant.
“In the case of the viability of the seeds of this fossil, the seeds produced the stems of the embryo, which are quite evident in the amber,” he said. “It is unclear whether those stems, known as hypovars, appeared before the cone encapsulated in the amber. However, based on their position, it appears that some, if not most, growth occurred after the cone fell into the resin.”
A study of viability in existing seeds suggests that the condition could be associated with winter frosts, OSU says. According to Poinar, light frosts would have been possible if the Baltic amber forest had a humid, warm and temperate environment, as shown.
“This is the first fossil record of seed viability in plants, but this condition probably occurred a little earlier than this eosen record,” he added. “There is no reason why vegetative vitality could not have occurred hundreds of millions of years ago in ancient spore-bearing plants such as ferns and lycopods.”