Ancient date seed producing fruit
Given the right conditions, some seeds can be stored for years. And, amazingly, in some cases, thousands of years, as Eva Higginbotham heard...
Eva - Back in 2008, we spoke to scientist Sarah Sallon from the Louis Borick Natural Medicine Research Centre at Hadassah Medical Organisation in Israel, about an ancient date seed, found in Israel in the 1960s, and then kept in a university drawer for years, which she and colleagues had managed to get to germinate and grow into a seedling.
Sarah [in 2008] - And then when a little date seedling, which we nicknamed Methuselah was about a year and a half old, she found tiny fragments of the shell still attached to the rootlets, and the results came back about 2000 years.
Eva - That's right. Back then the 2000 year old seed was just getting started. And now, 13 years and several ancient seeds from a few different locations later, there's a whole gang.
Sarah - They are called Methuselah, Adam, Jonah, Boaz, and Uriel. And two females who are called Hannah and Judith.
Eva - And they've grown up too. Little Methuselah is now about seven metres tall and the first female, Hannah, about two and a half metres. But first things first, I asked Sarah, how can trees be male and female.
Sarah - Date palms are a bit like people, but not like people. So if you have a boyfriend and you have children, then those children will be part of your DNA, and part of your spouse's DNA. And date palms are exactly the same. They're female, lady date palms, and male date palms. And if you take pollen from the male, and you sprinkle it on the female flower, then eventually, hopefully you get baby dates, which are the actual dates that the female produces. And those dates are a mixture of mum and dad, that's called sexual reproduction because you need a male and a female, but date palms also produced, what's called asexually, meaning that if you, Eva, grew a little Eva on your side and it was taken off, it would be a clone of you, exactly the same as you, and date palms also make clones of themselves. They're called offshoots.
Eva - And then last year, something very special happened.
Sarah - During the corona, our good news was Hannah produced her first flower, which means that she was ready to have a baby. So my colleague who grew the dates, Elaine Solowey, took some pollen from Methuselah and she pollinated the flower. And lo and behold in September last year, Hannah produced some beautiful dates. So here she just produced a hundred individual dates, really just a kilogram, really, but they were very nice. They were very sweet, but not sticky sweet, sort of dry sweet, and with a very kind of pleasant after-taste. And I don't actually like dates that much, because they're a bit too sweet for me, but I like these very much.
Eva - And now that Hannah is producing dates and so seeds of her own, I asked Sarah, if she's going to plant them to make some baby Hannahs?
Sarah - What they've done over the centuries is, if they find a female who's grown, maybe hundreds of years ago from a seed, but she's a super female, she produces wonderful dates and lots of them. Then what they did is they cloned them by taking the offshoot of that female and planting it, and planting more and more offshoots, because you'll always get the same date, if you do that. You'll get identical females and they'll all be super producers. So for scientific purposes, we've been planting out the seeds just to see what comes up, and genetically what they're like, but to produce a very nice, let's say commercial date from Hannah, then we would take offshoots of Hannah and plant them out. And each of those little trees will be baby Hannahs. That will go to big Hannahs that will produce exactly the same fruit. But the thing is, it takes a long time. So what people do now in the date industry is, they don't take the offshoots and plant out one offshoot. They do something called tissue culture, which means they take a piece of the offshoot when it's pretty fully grown. And in the laboratory, they make hundreds of little seedlings in the laboratory from one offshoot and they're all identical. And that's what we would like to do with Hannah. But I must tell you that this year Hannah has produced right now, six flowers. So what we've done is we've pollinated the different flowers with different males. So there's Methuselah in one, and they're all labelled, And then there's another, that's been pollinated by Jonah and another by Adam. She's kind of got multiple husbands now, and we'll see whether there's any difference in the taste or the size, but generally taste and size is a female characteristic. So it probably won't make that much difference.
Eva - Sarah has been working with collaborators in Montpellier, France, to study the genetics of Methuselah, Adam, Judith and the rest. And they've been comparing the results to the DNA found in the hundreds of modern date varieties, we have today to look for family resemblance,
Sarah - The oldest trees, which are Methuselah and Adam, they're dated to about 300-400 BCE at the earliest. And they most resemble Arabian varieties. Which is very interesting because Arabia was one of the first places to domesticate the date palm, nearly 6,000 years ago. But then the trees that are a little bit younger, like Hannah and Judith, the two females, they're mostly very similar to modern Iraqi varieties. And then we've got the younger guys in the study Uriel and Jonah and Boaz, and they're younger. They date from like the first or second century of the common era. And they are much more like North African date palms. And it really follows a kind of time progression. The younger they are, the more what we call Western they are, meaning they're more North African, which is the Western type date palms. The older they are, they're more like what we call the Eastern date palms, which is everything really, east of Egypt. And Israel is kind of in the middle between these Eastern and Western sections. So our date palms have a mixture of both, but the younger ones are certainly much more Western. And the older ones are very Eastern.
Eva - It's likely that the dry environment the seeds were found in played a significant role in their survival for so many years. And Sarah also hypothesises that perhaps there is something special about this part of the world. Some of the seeds were found in the same cave as the famous Dead Sea Scrolls, where it's very, very low altitude and there is weaker UV radiation. And Sarah thinks that may have helped preserve the DNA in the seeds for long enough that when they were found, they were ready to wake up. She's written a book called The Date's Tale, which tells Methuselah's story through his own eyes from when he was first discovered. And as she told me, he's a bit of a poet.
Sarah - The date awoke that morning to the sound of tapping, not the rustling of winds, sweeping through pillars of salt, not the sighing of a lifeless sea far below. No, this was a tapping of metal against stone, a clanking, dragging, scratching sound. The date reflected. It's a tool, he thought. They are looking for me. They have come to take us home. Brothers and sisters awake! Our days of rest are over. They will plant us and tend us as they did when we were children. But the seeds did not stir, not a thought, not a dream, not a sound disturbed their repose. Fellow seeds, said the date impatiently, they have come, as they promised, why do you not stir yourselves? But the seeds, and the storehouse, and the great palace built by a madman was silent. Only the tap, tap, tap of metal against rock echoed in the morning sun.