Dendrobium superbiens (an amphidiploid with PPCC genome constitution) was crossed to D. Manoa Beauty (PPPP-type genome constitution) on February 6, 1991. The relatively uniform PPPC offspring (K1420) began to flower about 25 months after germination. The attractive dark purple-violet flowers are large and full, measuring about 3 inches across with overlapping sepals and petals. About 12 flowers are carried on erect flower stems. The average height of pseudobulbs at first flowering was 9½ inches, and after the third year of flowering was 26½ inches. Flowering peaked from July through December (see chart). Bud drop percentage was low (under 3%), and the half-life of sprays on plants was about 60 days. The half-life of sprays on plants is the number of days it takes for half of the flowers on the spray to wilt or drop. The cross, K1420, was registered with the International Orchid Registrar as Dendrobium Mari Marutani.

The genome make-up of D. Mari Marutani (D. superbiens x D. Manoa Beauty) is similar to that of D. Pompadour (D. Louis Bleriot x D. phalaenopsis), an important cutflower cultivar in Thailand. Dendrobium Mari Marutani has one chromosome set of D. discolor contributed by amphidiploid D. superbiens and three sets of essentially D. phalaenopsis chromosomes contributed by D. superbiens and D. Manoa Beauty, while D. Pompadour has one set of D. discolor chromosomes contributed by an unreduced egg from triploid D. Louis Bleriot (D. superbiens x D. phalaenopsis) and three sets of D. phalaenopsis chromosomes contributed by D. Louis Bleriot and D. phalaenopsis. A significant difference between the two cultivars is that ‘Mari Marutani’ is seed-propagated, whereas ‘Pompadour’ is clonally propagated.

The major attributes of ‘Mari Marutani’ are the relative uniformity of the seed-propagated progeny, the attractive dark purple-violet flowers with overlapping sepals and petals, the low bud drop (2.5%), and the long half-life of sprays on plants (about 60 days).

Flower color (RHSCC)

Red-purple (80A)

Flower length

2.4 ± 0.1

Flower width

2.9 ± 0.2

Petal length

1.6 ± 0.1

Petal width

1.4 ± 0.1

Dorsal sepal length

1.4 ± 0.1

Dorsal sepal width

0.7 ± 0.1

Pedicel length

1.7 ± 0.2

Scape length

7.3 ± 1.1

Raceme length

20.4 ± 3.1

Flowers per spray (number)

11.7 ± 4.3

Bud drop (%)

2.5

Sprays per plant (number)

6.1 ± 2.2

Half-life of sprays on plant (days)

62.0 ± 2.2

Pseudobulb height at first flower

9.4 ± 1.9

Pseudobulb final height

26.6 ± 4.9