|
|
Amphidiploid Dwarf and Median
Bearded Irises
|
When
I. pumila is crossed with a 48-chromosome bearded iris (such
as a modern tall bearded), the result is a plant with two sets of 8
chromosomes from I. pumila and two sets of 12 chromosomes from
the other parent. This configuration (known as an amphidiploid) is
generally fully fertile. The modern standard dwarf bearded irises
virtually all belong to this 40-chromosome fertile family. Amongst
wild irises, the species I. lutescens in its various forms has
essentially the same chromosome makeup, and is thus also part of the
same fertile family. Other apparent members of this family are I.
bicapitata and I. subbiflora.
Many fine new SDBs are produced each year, so
this family is going strong, second only to the tall beardeds in the
popularity and attention it receives.
The family can be expanded by making new
pumila x 48-chromosome bearded iris crosses. The original
crosses that launched the SDBs involved a number of forms of I.
pumila along with a range of TBs from the mid-20th century. It
might be valuable to use different, modern TBs and BBs as parents,
and to use the 48-chromosome medians as well. If the TBs are used,
the seedlings will likely be larger than ideal for SDBs, but if the
medians are used, they are likely to be smaller, even falling in the
MDB range. Ben Hager produced a number of nice MDBs via this route,
and in fact many modern MDBs are of this sort, either derived from
Hager's lines, or simply short selections from SDB breeding. Still,
the potential here is not exhausted by any means.
Although work in this family is not one of my
priorities, I expect to make some tetraploid median x pumila
crosses for my edification.
Hall of Fame
Greenspot (Paul Cook, R. 1951).
Seedling 2148. SDB, Height 10" (25 cm), Early bloom season. White
self green spot on falls. Cook 10942 X yellow Iris pumila. Honorable
Mention 1951, C-D '59, CDM 1968. Longfield 1951.
Although there are any number of those
first-generation SDBs from the pioneering TB x I. pumila
crosses that might be singled out as classic achievements, I have
selected 'Greenspot' because of its enduring popularity as a garden
plant and its use in many different types of breeding over the years.
It showed off the potential of the pumila spot pattern in
median breeding and modeled the flower and plant proportion desirable
for the SDB class.
Lenna M (Earl Roberts, R. 1964). Sdlg.
64R13. SDB, 10" (25 cm), E. Color Class-OlP, S pink; F pink, deeper
beige spot, white-pink border; white beard tipped red. (TB orchid
sdlg. x Barium Gold) X Zickler sdlg: ((Twilight Sky x white pumila) x
(Desert Song x white pumila)). Roberts 1966.
Early on in SDB breeding, it was thought that
the recessive TB color patterns, such as the plicata pattern and the
tangerine pinks, might not be possible in the SDB class. I have
chosen 'Lenna M' as an example of an early breakthrough in this area;
it was quite a sensation in its day as a pink SDB and was much used
in breeding. Although it would be a number of years until pink and
orange SDBs improved enough to win top awards, these early
accomplishments laid the groundwork for the great color variety we
have today.
Libation (Ben Hager, R. 1974).
Seedling AHD2541B . MDB, height 5" (13 cm), Mid to Late bloom season.
Standards wine red; falls deeper wine red, darker spot area; yellow
beard. 'Prodigy' X ('Scale Model' x 'Brownett'). Melrose Gardens
1975. Caparne Award, 1979.
I've included 'Libation' as an early and
popular example of Ben Hager's work in producing MDBs from combining
I. pumila with his aphylla-based tetraploid MTB lines.
MDBs from this type of breeding are fully fertile with SDBs, but
retain a natural daintiness appropriate to the miniatures. It is
partly because of such work that so many nicely formed and varied
MDBs are available today.
Chubby Cheeks (Paul Black, R. 1984).
Seedling 824E. SDB, height 12" (30 cm), Early bloom season. Standards
white ground, stitched light violet, greyed chartreuse band; falls
white ground, stitched violet around outer portion, widely banded
greyed chartreuse; pale violet beard tipped tangerine in throat;
ruffled; pronounced sweet fragrance. Sdlg. 824E:( Black's Seedling
B80-20 : (Concord Touch x Daisy) X Soft Air). Mid-America Iris
Gardens 1985. CDM 1991.
The wide-petaled form of this SDB has
transformed the class. It is arguably the best SDB breeder ever
produced, with a multitude of superior offspring introduced over a
span of more than two decades.
Gallery
|
|
|
|
|
'Orange
Tiger' (B. Jones 1988) SDB
|
'Michael
Paul' (W. Jones 1979) SDB
|
'Sea Monster' (L. Miller
1993) SDB
|
Plant List
The list below shows the name of each plant I
currently grow for breeding purposes, the source, and the year
acquired.
Illustration: 'Gizmo'
(Hager '76): an MDB from I. aphylla breeding.
Tom
Waters
September 2010
updated April
2012
Unless otherwise noted, all text
and illustrations copyright Tom Waters and all photographs copyright
Tom or Karen Waters. Please do not reproduce without
permission.