Another Durian blog

Like all Durian websites, it's a bit odd:

Above Average: Durian Links and Information

Any fruit-related site that also works in a reference to Gigantopithecus is just fine by me.

Warning: This site will play music at you. Adjust your volume accordingly. I told you...the Durian people are odd.

The Native Papaw

Someone on the NAFEX list forwarded on this link to an online version of an old USDA pamphlet on pawpaws:

The Native Papaw (University of North Texas)

Stern's Medlar, Revisited

Way back in the Dark Ages of the Fruit Blog, back when I actually wrote long articles, I wrote an post on medlars, which mentioned Stern's medlar, aka Mespilus canescens. I've always been fond of Stern's medlar, mostly because I'm fond of outliers in general, and this thing is definitely an outlier.

The genus Mespilus has long been one of those single species genera, consisting only of M. germanica, the European medlar. So the discovery in 1970 of a medlar species, a hemisphere away from all other naturally occuring medlars, in Arkansas of all places, is certainly surprising. The fact that it exists only on one site, with only 25 individuals, that it only rarely flowers, and that it turns out to be triploid, are that much more unusual.

In fact, probably too unusual to be the real deal. A little while ago I had a great e-mail from Thomas Frothingham, who has worked with M. canescens, with an update on the latest thinking on the species. I'll repost it here verbatim, rather than just paraphrasing his whole letter for you:

I happened across your website today, and I thought I would pass along some information about the Stern's medlar. In a former job, I worked extensively with this species in situ, at the Konecny Grove Natural Area. There has always been controversy about the taxonomy of this very rare plant, but the latest thinking, based on the genetic analysis of the entire Crataegus tribe by Dr. J.B. Phipps [EFL: The paper is actually by Lo et al., not Phipps, though Phipps has been a prolific researcher in the field of Crataegus and Mespilus taxonomy], is this: the Stern's medlar is an accidental hybrid between The blueberry hawthorn (C. brachyacantha) and the European medlar, Mespilus germanica. I can send you the original article if you're interested. It seems likely to me that the germanica plants were brought to the area early in the 20th century, when there was an influx of immigrants from the area of the Czech/Austrian border region. The influence of these settlers is very evident today: the nearest community is the town of Slovak, there is an Eastern Orthodox church nearby, the nearest cemetery is named the Czech National Cemetery, etc. Also the area is still populated with people of Czech ancestry (the Konecnys, Orliceks, etc).

At one time the population of Stern's medlar was managed as one of the rarest tree species in the world. If the hybrid theory is correct, it may change that perception. On the other hand, the blueberry hawthorn is tracked as a species of concern, and has been extirpated from the Grand Prairie region of east Arkansas (the original prairie has been almost entirely converted to rice production). So the Stern's medlar is at least preserving some of the genetics of a rare species.

To answer some of the questions posted on your blog:

To my knowledge, the Stern's medlar is not available commercially. Any attempt to market it would have to take into account the ownership rights of the landowners (the Konecny Grove Natural Area is privately owned, managed through a conservation easement by a state agency. It is also not open to the public). The plant also has some limitations as an ornamental: the period of bloom is very short, and the flowers smell bad. It has so far proven impossible to propagate by cuttings or tissue culture, although I assume it could be grafted. The only reliable method so far is to carefully dig up the suckers from around the base of the parent plant. There are some specimens at the Center for Plant Conservation in Missouri, and also I believe at the National Center for Germplasm Research in Corvallis, Oregon.

The reason it hasn't bloomed in recent years is probably due to the succession process, as the canopy closes and the plants are increasingly shaded. The use of prescribed fire and removal of surrounding trees has been implemented to reverse this process. The other problem with managing this plant in the wild has been the presence of invasive Japanese honeysuckle and privet. These plants have been removed manually, which is very labor intensive. The last time I saw it, the grove was in good shape. This natural area is also the habitat for a number of other rare plants, and so it will continue to be managed carefully, regardless of the conservation status of the Stern's medlar.

It would be extremely interesting to replicate the original cross between the two presumed parent species-in other words, cross pollinate between a European medlar and the blueberry hawthorn. The seedlings from such a cross would presumably be Stern's medlars.

He also passed along a copy of the Lo et al. paper* (which I would be happy to share with any one interested). It's not the easiest reading, at least from my point of view (as much as I like taxonomy I find taxonomy papers mind-numbing), but buried in there are the evidences for a hybrid origin of M. canescens:

1. Nuclear sequence data showed M. canescens shared a recent common ancestor with the M. germanica samples, but chloroplast sequence was actually much more closely related to C. brachyacantha.


2. Stern's medlar shares many characteristics with C. brachyacantha that it does not with M. germanica: petals that turn orange upon drying, multiflorous inflorescences.


3. C. brachycantha occurs naturally in Louisiana, eastern Texas, and adjacent portions of Oklahoma and Arkansas. M. germanica, while native to Europe, is recorded to have been grown in Louisiana as long ago as 1893, placing the two species in close proximity of the only known site of Stern's medlar.


4. Both sexual (×Crataemespilus) and graft (+Crataegomespilus) hybrids between Crataegus and Mespilus. (I've discussed the general promiscuity of the whole Mespilus / Crataegus / Sorbus / Pyrus / Amelanchier club before).


5. There are a lot of reasons to reconsider Mespilus' standing as a distinct genus and include it in Crataegus.

They basically propose the following scenario for the origin of M. canescens:

• Sometime, probably 150-200 years ago, pollen from cultivated medlars was transferred to a flower of blueberry hawthorn, resulting in hybrid seed.


• The resulting seed produced hybrid individuals. However, because of differences between the parent species, meiosis was irregular and the hybrids were largely infertile.


• The only viable gametes produced by this primary hybrid would have been unreduced, and thus diploid.


• With these unreduced ova, occasional seed set might have occurred, and in those cases the pollen parent could have been either a medlar or another native diploid hawthorn (possibly red-fruited, like M. canescens).


• Stern's medlar is the result of these secondary hybridizations.

I have to admit they lay out a pretty compelling case, both for revoking species status for M. canescens (they suggest designating it Crataegus ×canescens) and for absorbing Mespilus into Crataegus. But my personal taxonomic system is based more on sentiment than on anything else, and I'm definitely a splitter, not a lumper. So I'm going to keep Mespilus, and I'm going to keep calling Stern's medlar a medlar, because it's cooler that way.

*Lo, E.Y.Y., Stefanovic, S., and Dickinson, T.A. (2007) Molecular reappraisal of relationships between Crataegus and Mespilus (Rosaceae, Pyreae)—Two genera or one? Systematic Botany 32(3) 596-616.

Transgeninc plants in Hawai'i: A new colonialism?

Hawai'i has the distinction of being the site of the first (and I think only) commercial trangenic fruit crop, a transgenic virus-resistant papaya. Without the transgenic papaya, there basically would be no Hawai'ian papaya industry. Even what little non-transgenic papaya production is left survives only by burying it in buffer zones of the transgenics.

Because of the level acceptance already in place for transgenic papaya, and probably because of the relative isolation of the island, Hawai'i is a popular plance for trials of transgenic crops. That's not real popular with some folks.

I'm a month late getting this posted, but Karl Haro von Mogel has a post on this up at Biofortified:

Hawai'i's curious relationship with with GE (Biofortified)

I can't remember if I've posted it before, but Karl's own blog, The Inoculated Mind is also worth a read.

#39 is good enough by me

Well, I know absolutely nothing about the website, but I'm not going to question anyone who ranks The Fruit Blog among the top 50 genetics blogs.

Even aside from the opportunity to brag about my honors, it's worth checking out, because there are some great sites there. Some, like Sex, Genes, and Evolution, John Hawks' Weblog, and Pamela Ronald's Tomorrow's Table, I've been following for a while, but there are a bunch of others in there that look absolutely fascinating.

(Considering they seem to have grouped them by category, I suspect the ranking is meaningless.)

New strawberries from the University of Florida

I added these to the "New Cultivars" section in the sidebar a while ago, but this is the first article I've seen on the new U.F. cultivars, Radiance and Elyana:

Safeguarding Strawberries (American Vegetable Grower)

I saw plants of both these varieties last week, and I was struck by how odd a plant 'Radiance' is. It's got sort of a soft, floppy look, like it's just slightly water stressed.

'WineCrisp' Scab Resistant Apple

The cooperative apple breeding program of Purdue, Rutgers, and University of Illinois (aka PRI) has a new release: Wine Crisp.

WineCrisp--New Apple 20 Years in the Making (University of Illinois)

I have a sneaking suspicion that the name is a thinly-veiled attempt to capitalize on the popularity of 'HoneyCrisp', but it's not like the University of Minnesota owns the concept of crispness I suppose.

The PRI cooperative has released a lot of varieties over the years, although probably the only one I ever saw with any frequency was Gold Rush (an interesting apple in that it is far better after months of storage than it is fresh, at least in my opinion). The main emphasis of the program has always been disease resistance, especially scab resistance. WineCrisp (and many other scab resistant cultivars) use the Vf gene.

I wrote up a whole big thing on the inheritance of major gene resistance to scab, but it got involved enough that I decided not to leave it attached to this, but rather to to A) finish it, and B) take advantage of actually having something written and available that fits as a "Fruit Genetics Friday" entry, so maybe I'll roll it out later this week.

Bramley's Seedling Bicentennial

Happy Birthday Bramley's Seedling--200 years old in 2009 (Fruit Forum)

There's even a collection of features and events in honor of the occasion (even what they claim is the first "video pie-cast").

Charlie is my Darwin

Over on ScienceBlogs, a fellow by the name of John Whitfield has taken on the task of "blogging" Charles Darwin's On the Origin of Species:

Blogging the Origin (ScienceBlogs)

I don't especially want this site to become a debate of evolution, but regardless of your views on the subject, the Origin is still worthwhile reading, and of great relevance to the actual purpose of this site. It's a study of genetics before there really was much in the way of a field of genetics, and ultimately, it's a study of variation in living organisms--and variation is at the very core of fruit breeding. Darwin doesn't always get it his individual points right, but the man had an amazing eye for variation in nature.

(Darwin dealt more specifically with matters of domestication in a later work, and actually wrote an entire book on inbreeding, an important concept in plant breeding.)

I really like the idea of "blogging" books (Lady Evil Fruit absolutely loved Slate.com's Blogging the Bible) and I'd do it here except I'm too lazy and I don't have a particular book in mind...

A whole bunch (er, hand?) of banana articles

The New Agriculturist has a series of articles on African bananas:

African banana--on an upward curve (New Agriculturist)

Brought to my attention, as is so often the case, by the Agrobiodiversity Blog (they even threw in a bonus story on carotenoids in bananas...)

"Florida Grapes" website gone?

I was just clicking through my links, and I found two of them that don't work, which is always a bummer. One of them, Rare Fruit Online, is at least still available through Archive.org (you can find it here) but the Florida Grapes website appears to have disappeared along with AOL's Hometown web service back in October, and isn't archived on Archive.org. Nor does it appear to be in the Google cache. (If you'd like to see it not working yourself, click here).

This is a major sadness for a pedigree junkie like me, because the site was a great source for parent information, particularly the selections from the programs of two of the "Three Bobs", Dunstan and Zehnder.

From my contacts within the grape breeding community, I feel fairly certain that that information is still preserved somewhere out there. But still, it's one thing for information to be available somewhere in some one's notebooks or spreadsheets, and another for it to be one Google search away.

If anybody has the pedigree information from this site, I'd try to put it online somewhere myself.

For now, I'm pulling both links from the sidebar. (As a condolence, I'm adding the Bananas.org forums).

The most Mendelian of Mendelian segregation

This isn't really fruit related, but it is breeding related, so I declare it relevant:

Pea Breeding Project (Daughter of the Soil)

(I was inspired by the Agrobiodiversity Blog's mention of it, but I've been following Rebsie's blog for a while, so I'd have gotten around to it eventually.

'Ohio Everbearing' black raspberry

When I first heard about the 'Explorer' primocane-fruiting black raspberry, I was convinced it was the first such variety. As it turned out, I was wrong, as numerous such cultivars existed by the turn of the century, although very few ever achieved any importance.

An exception to this, however, is the very first primocane-fruiting black raspberry, 'Ohio Everbearing'. Although not a major commercial success, this variety remains significant as one of the very first cultivated American selections of Rubus, and probably the first named black cap (given the abundance of wild black raspberries, it probably took an unusual trait such as fall-fruiting to warrant a name and cultivation).

'Ohio Everbearing' was discovered in the wild by Nicholas Longworth. Longworth was a self-made millionaire banker from Cincinnati, which in 1804 when he moved there was almost the western frontier. Although his family remained important in local and U.S. politics, and he left an estate worth $10 million when he died in 1863, Longworth's most lasting legacy is as a horticulturist. Often called "The Father of American Viticulture" (a title sometimes applied to his correspondent, John Adlum), Longworth was an avid collector and disseminator of fruit varieties. He championed first the 'Alexander' and then the 'Catawba' grapes and introduced at least one strawberry of his own creation.

Everbearing Black Caps listed in Fred Card's Bush Fruits (1920) American Everbearing Cottier Everbearing [Grigg's] Daily Bearing Earhart Everlasting Every Day Fadely General Negley Hixon's Everbearer Kagy Everbearing King of Cliff's Lum's Autumn Black Raspberry Lum's Yellow Canada Miller's Daily Bearing Munson's Everbearing Mystery Ransom's Everbearing Sweet Home Wonder

Longworth found the original 'Ohio Everbearing' somewhere in central Ohio, where he had retreated in the fall of 1832 to escape cholera outbreaks in Cincinnati. Despite it being September or October, he "found a raspberry in full bearing, a native of our state, the only everbearing raspberry I have ever met with. I introduced it the same winter into my garden, and it is now cultivated by me in preference to all others, and my table is supplied from the beginning of June to frost." Although the variety struggled somewhat on the gravelly soils of his fields, it performed better on clay soils, and Longworth was convinced it might have a future, especially in England. He sent plants there, as did A.J. Downing, though it seems have had little impact there. The legendary Dr. Hogg did note its existence in England as late as 1884, when it was probably gone in the U.S. (Incidentally, in my hypothetical strawberry-themed band, my stage name was going to be "Dr. Hogg").

Longworth was among the foremost horticultural authorities of his day, and an everbearing variety of raspberry would seem to be a major development, so it seems like it should have caught on, but while he and a few others cultivated it commercially, it never seems to have. Black caps, in general, have never attained commercial prominence, perhaps because they were foreign to European tastes, and thus unable to compete with the more familiar red raspberries. Many other everbearers, such as 'Grigg's Daily Bearing', 'Miller's Daily Bearing', and 'Lum's Autumn Black' were selected from its seedlings. (Indeed, I rather suspect most, if not all, of those everbearing black raspberries that appeared in the second half of the nineteenth century may claim it as an ancestor. Most of these seem to originate in Ohio, Kentucky, Indiana, or Illinois, the areas nearest the discovery and commercialization of Longworth's variety).

And while we're talking about obscure fruits with Z's in their names...

I recently came across this fairly thorough discussion of Syzygium species from the Philippines on the blog Market Manila, with the common names "makopa" and "tambis". The discussion features a number of photos and spans three posts:

Tambis / Makopa / Curacao or Malay Apple
The Tambis (Syzygium Aqueum) Chronicles, Take II…
Tambis & Makopa Side By Side…

I don't really know much about the Myrtaceae. I was reminded of these posts because Syzygium sounded kind of like Ziziphus, and had it in my head that the two fruits looked kind of alike (although not so much, now that I look at them again). I thought maybe they were related, but no, not remotely--they're not even in the same order.

Jujube jujube?

I just came across an interesting tidbit on the nomenclature of the cultivated jujube (mostly on an obscure corner of the internet called Wikipedia...)

Ever since I learned the jujubes were actual fruit and not just a type of candy, I've been using Ziziphus jujube as the Latin name (now, granted, it's not like the Latin binomial for jujube comes up in my daily conversation that much). Well, apparently I'm a little bit behind the times, because the name seems to have been Ziziphus zizyphus since 1882.

I personally am so easily amused that this alone would be adequate to entertain me, but the story of how it wound up with that name is kind of interesting as well. In general, tautonyms (those in which the genus and species names are identical), while permitted in zoological nomenclature (hence Gorilla gorilla and Iguana iguana) are no good in botanical names. However, this one skated by on a technicality.

It was Mr. Taxonomy himself, Carolus Linnaeus, who gave the species its first modern binomial, Rhamnus zizyphus, placing it in the same genus as the buckthorns. However, in 1768 Philip Miller (a late and reluctant adopter of Linneaus' binomial system) decided it was sufficiently different to merit a separate genus, and gave it the name Ziziphus jujube. Why he changed it from a 'y' to an 'i' is unclear--it might well have been a typographical error. However, the arcane rules of taxonomy dictated that because Ziziphus and zizyphus were the first validly published and described names, and were not actually in violation of the tautonym rule thanks to the spelling difference, and thus the appropriate name, so in 1882 the name was changed to Ziziphus zizyphus.

And yes, I realize I'm probably one of about three people who found that interesting.

Kid's version of the Endicott pear story...

Not real fancy, but still kind of nice. I can appreciate any attempt to get kids interested in horticulture. It held my two-year-old's attention for nearly a minute, which is about 45 seconds longer than almost anything else I've tried this afternoon.

A Tree Grows in Danvers (USDA-ARS)

Primocane-fruiting black raspberries, revisited

I was pleased to find a note in my e-mail this morning from Pete Tallman, developer of the 'Explorer' black raspberry. I mentioned 'Explorer' two years ago (have I really been at this that long?) as an exciting development in a crop in which very little breeding has been done (and, frankly, very little breed success obtained).

Unfortunately, 'Explorer' has not really been a success. I've seen it twice, both times under tunnels: once in Pennsylvania, where it had virtually no fruit and a powdery mildew problem, and another time in upstate New York, where the plants looked healthier but fruit set was still poor, though better. I was rather disappointed, as I'd been pretty excited about the thing.

Tallman's message today explains a big part of the problem: 'Explorer' is not self-fertile. Apparently his field featured things that flowered and provided adequate pollen at the right time, so the problem was never evident under his conditions. This fits with what I saw: the tunnel at Penn State where I saw it had, if I recall, only one other variety in it, while the one in NY, where it had at least some fruit, had several.

While unfortunate, this isn't entirely shocking, as self-incompatibility is fairly common among wild, diploid Rubus, and 'Explorer' is not far removed from the wild source of the primocane-fruiting trait that Tallman discovered. (Not surprisingly, the trait hasn't persisted very long in most commercial types).

Anyway, all is not lost. Tallman has selected another primocane-fruiting black raspberry, dubbed PT-2A4, which does pass the self-compatibility test, and has other desirable traits compared to 'Explorer'. As he describes it:

"Compared to Explorer, the PT-2A4 berries are larger, higher drupelet count, and smaller seeds. PT-2A4 holds my all-time record for a single primocane black raspberry at 3.82 grams. Admittedly, that's a max berry, not an average, but I gotta track something, and average isn't awfuly interesting. Maybe with a little fertilizer this year I could break 4 grams. Unfortuantely, PT-2A4 hasn't captured the reduced thorniness of Explorer, so there remains further breeding down the road to see if I can tie that trait back in again."

He also included a link to his website, which includes a page for PT-2A4.

New grape rootstocks from the University of California

Five new rootstocks from Andy Walker's breeding program at UC-Davis (cleverly named GRN-1 through 5):

New nematode resistant rootstocks for 2008 (Western Farm Press)

I was particularly pleased to see that GRN-1 is a hybrid of bunch grape and muscadine. Despite lots of talk about Euvitis/Muscadinia hybrids, there really haven't been many releases (I can only think of this and 'Southern Home', as well as maybe a few germplasm releases).

I don't know nearly as much about grape rootstock breeding as I do about the above ground part, but I always enjoy seeing how much wild material is used, and the completely different selection of species they're dealing with: V. champinii, rufotomentosa, monticola, rotundifolia, rupestris, and berlandieri, just in these five releases. Some of these (especially the first three) rarely if ever occur in the pedigrees of fruiting vines.

A new year and a new look for the Fruit Blog

Well, I know I've been a bit scarce lately...between the holidays and everything else my mind's just been elsewhere. But I made a sort of New Year's resolution to keep this thing going, so I sat down to write a new post...

...and instead I re-did the blog template. Hopefully everyone likes it. I don't really know HTML that well, and there are still lingering issues (expect tinkering here and there for a while). There wasn't really a grand vision or anything--I just started screwing around with things.

The first thing you'll probably notice is the second sidebar. I decided to do this because to put everything in the one sidebar meant that useful things frequently got buried way, way down at the bottom. I may have somewhat reduced the impact of this by interspersing the fruit watercolors (from the USDA collection), but I thought they looked cool, and they kind fixed my problem with the grey not going down to the very bottom of the page like I wanted. I know things are a little more cluttered now...but hopefully not unreadably so.

Probably the biggest addition is the "Books" section in the sidebar. These are books about fruit and breeding that I've found interesting over the years (I don't actually own all of them, but I do most, and I've at least looked at all of them). The titles link to their respective Amazon pages (although some are out of print, and so your only hope is going to be a used copy). In the interest of full disclosure: I am a part of the Amazon Associates program, and get a cut (a very small cut) of anything you buy through these links. I have mixed feelings about this, since I didn't create this blog with the intention of making money (and what a fool I'd have been if I had!). But I do have a few costs here and there (domain name registration, for example) and a couple of bucks would provide me a little more incentive to keep things going around here when things get slow. I've been approached several times about placing ads on the site, but I've always turned them down. This way I keep control of what gets advertised, and hopefully people find some interesting or useful books. (It's kind of a pain to set up the links, so I have to admit I didn't put a ton of care into their organization or selection. I'll keep adding and arranging this section over time. If you have any suggestions you'd like added, let me know).

Anyway, hope everyone had a happy holidays, and hopefully you'll be seeing a little more of me. Please let me know if the new layout has screwed something up for you, or if you hate it or would like to see other enhancements.

Update: I've checked the new template in Safari, two versions of Firefox, and Flock. I'll check it in Chrome and Explorer when I get to work on Monday, but frankly I don't hold out a lot of hope for Explorer...the site's always looked kind of crappy on it, and I doubt this made it any better.