UH1081 Den. Uniwai Royale

University of Hawaii
Horticulture Digest #105, July 1995

A few seedlings from a self-pollinated progeny of Dendrobium Jaquelyn Concert were received in 1969 from the late Ralph Yagi of Maui. The seedlings were relatively uniform and produced dark purple-red flowers on long erect flower stems. Chromosome counts showed that they were tetraploid.

A selected individual, JCS1-49, was self-pollinated in 1973, and two seedlings, K327-16 and K327-7, were sib-mated in 1979 to produce a third generation inbred population, K634. The inbred selection, K634-29, produced large, dark purple-red flowers on erect flower stems.

In 1985 four crosses were made involving the inbred Jaquelyn Concert K634-29 (S₃), inbred white Jaquelyn Thomas, K159-26 (S₂), K671-16 (S₃), and K672-18 (S₄) and purple Jaquelyn Thomas, D168-12 as follows:

K1078 Jaquelyn Thomas, K672-18 x Jaquelyn Concert, K634-29

K1080 Jaquelyn Thomas, K671-16 x Jaquelyn Thomas, D168-12

K1081 Jaquelyn Thomas, K671-16 x Jaquelyn Concert, K634-29

K1088 Jaquelyn Thomas, D168-12 x Jaquelyn Thomas, K159-26

K1088 (= UH507) served as control. The parents of K1080 were similar to K1088, except for the white Jaquelyn Thomas parents, K671-16 and K159-26. Both K1078 and K1081 were crosses between inbred Jaquelyn Concert, K634-29, and inbred white Jaquelyn Thomas, K671-16 or K672-18.

The crosses were made in June, 1985, germinated in September, 1985, compotted in May, 1986, potted in 2-inch clay pots with tree fern fiber in September, 1986 and repotted in gallon-size plastic pots with No. 3 blue rock in June, 1987. Plants were grown under 30 percent polypropylene shade and evaluated from 1987 through 1992.

Table 1 gives the characteristics of the four progenies under evaluation. K1081 produced larger flowers than the other three crosses. Scape length was slightly shorter than that of K1080, but spray length was equal to that of K1080. The average number of flowers per spray of 18.6 for K1081 was equal to that of K1088 (UH507). Bud drop percent was low, and the half-life of cut sprays averaged between 20.3 to 22.2 for all crosses.

The total spray yield of K1081 was higher than that of K1078 and K1080 and equal to that of K1088 (Table 2). In addition K1081 produced flowers throughout most of the year with a major peak in June and a minor peak in December (Fig. 2). Furthermore, the flowering peaks did not always coincide with those of K1088.

K1088 (UH507) produced pseudobulbs averaging 42.2 inches, as compared to 34.6 inches for K1081. One of the undesirable features of UH507 is tall pseudobulbs. 

Among the four crosses evaluated, K1081 performed the best in practically all characteristics. Relatively large purple flowers were borne on erect sprays. Half-life of sprays was about 21 days. Bud drop percent was low. Pseudobulbs were sturdy and relatively short. Spray yield equaled that of UH507, and spread throughout the year with lower peaks and valleys than that of UH507. We are therefore naming K1081 (=UH1081) as Dendrobium Uniwai Royale and making this cross available to dendrobium growers for trial, possibly to complement the other purple flowered Jaquelyn Thomas cultivars, UH503 and UH507.