Showing posts with label Iris pumila amphidiploid. Show all posts
Showing posts with label Iris pumila amphidiploid. Show all posts

Tuesday, December 12, 2023

Using Species in MDB Breeding, Part 3: Iris reichenbachii x Iris pumila

by Tom Waters

This is the conclusion of a three-part posting describing projects with miniature dwarf bearded (MDB) and standard dwarf bearded (SDB) irises. The first and second installments were posted in July and October 2023. 

My goal for this hybridizing project is to produce a true-breeding line of MDBs that belong to the same fertile family as the SDBs and MDBs from SDB breeding. In theory, using species and species hybrids that are compatible with SDBs will circumvent the tall bearded ancestry that can lead to larger, out-of-class plants. The earlier installments cover the use of Iris lutescens and of a hybrid of Iris aphylla x I. pumila. 

The current post describes work with seedlings from I. reichenbachii x I. pumila. This third avenue of work is, to me, the most exciting and promising. However, I got started with it a bit later than the first two approaches, so it is less far along.

I. reichenbachii is a species native to the Balkan peninsula. It comes in both diploid and tetraploid forms. (The tetraploid species I. balkana is considered a synonym of I. reichenbachii.) Plants typically have very slender stems topped with two buds, ranging in height from about 6 inches to about 12 inches. Flowers are either yellow in color or some blend of violet, brown, and gray. This species is probably best known as a parent of Paul Cook’s famousProgenitor (R. 1951), which introduced the dominant bicolor pattern into tall bearded irises.

The tetraploid forms of the species belong to the same fertile family as TBs and I. aphylla. Hence crossing it with I. pumila ought to produce plants compatible with SDBs, just like the aphylla x pumila cross described in part 2.

tetraploid I. reichenbachii ex Mt. Vikos, Greece

I have raised a number of these (cross S026) from crossing a yellow tetraploid I. reichenbachii from Mt. Vikos, Greece, with I. pumila Royal Wonder (Coleman, 2013). About half the seedlings are yellow and half are purple. They are all about 5 inches tall, with one or two dainty flowers per stalk. Because I. reichenbachii is so much smaller and daintier than I. aphylla, I believe these plants have even greater potential to produce consistently small and dainty MDBs. I have made as many crosses with them as possible. So far, they are not cooperating as pod parents, although they produce plenty of fertile pollen.

S026-02
I. reichenbachii X 'Royal Wonder'
 
S026-05
I. reichenbachii X 'Royal Wonder'



















    











I am eagerly awaiting bloom in 2024 of seedlings from Miniseries (Keppel, 2011) X S026-02. Still in the pipeline are crosses of the S026 seedlings with Arson (Keppel, 2016, SDB), Come and Get It (Black, 2013, SDB), Dollop of Cream’ (Black, 2006), Oh Grow Up (Miller, 2018), Pearly Whites (Black, 2014), Self Evident (Hager, 1997), Tasty Treat(Johnson, 2020, SDB), and Pirate’s Apprentice (Hager, 2003). 

Multi-generational breeding projects like this one require patience and a certain amount of faith in the theory behind them. It can be a long slog with little immediate gratification. But it can also be very satisfying to pursue curiosity about paths not taken before and to learn as one goes. For me, this type of undertaking matches well with my limited space and my penchant for careful planning. Perhaps in a few more years, the groundwork described in these three posts will yield something worthy of being grown in gardens or meriting the attention of other hybridizers. Until then, the learning itself is a fine reward.