Just about every houseplant guide says that, while you can make transverse leaf cuttings of Sansevieria trifasciata (the cultivar shown is Laurentii, for a reason), the gold marginal variegation will be lost in the resulting plant.
Why is this? Leaf cuttings are basically clones, correct? So their genetic makeup should be identical to the parent plant. Why would something that should be genetic (the variegation) not cross over to the new plant?
Variegation can be due to a lot of different things like viral infection or nutritional deficiencies. Green to white variegation is usually due to loss of chloroplasts in the white tissue. Yellow or gold indicates that chloroplasts are still present but are defective in chlorophyll production. So, in fact, not all of the cells in the leaf are genetically identical; the green tissues have normal green chloroplasts while the yellow tissues have abnormal yellow chloroplasts. That plants propagated from leaf cuttings tend to lose their variegation suggests that only green leaf tissue are involved in developing the new plant.
Sansevieria trifasciata ‘Laurentii’ as well as many other Sansevieria cultivars with yellow banding are periclinal chimeras. That is, they are made up, as Terminus Est says above, of two genetically different tissues occupying the same leaf.
The new plant is almost always a clone of the green tissue, which is more vigorous. But according B. Juan Chahinian’s The Sansevieria Trifasciata Varieties, (a great book for Sans lovers which is unfortunately out of print) a leaf cutting will very rarely produce an all-yellow plant, which, lacking chlorophyll, will not survive on its own.
I clicked the link and was surprised to find a picture of the same type of plant that’s sitting right next to me now! So, how do the yellow parts arise in the first place? Is it a mutation that occurs as the plant grows?
Thanks, Terminus Est and KayElCee!
That’s about the gist of it. One thing I didn’t mention is that chloroplasts have their own DNA. The variegation could well be due to a mutation in the chloroplast DNA rather than the nuclear DNA.