Breeding Cut Roses for the Tropical Highland

Breeding and cultivation of cut roses has been confined to the temperate zones since the eighties of the last century. Since then several growers have left their fatherlands and started cut rose production in the tropical highlands of Asia, South America and Africa. Adaptation to the temperate zones of the varieties used, has led to disappointing results in the tropics. In addition to not being adapted to the tropics, the availability of patented varieties in non-UPOV countries has hampered the enlargement of local cultivation. The Dutch-Indonesian co-operative breeding programme BIOBREES aims at varieties of different horticultural crops which are performed better in Indonesia than hitherto. The rose part of BIOBREES aims at breeding cut roses, both by cross-breeding and biotechnology, that are adapted to the Indonesian highland (> 1000m asl). Within that scope the possibilities of breeding and selecting cut roses in the temperate zone, performing the well in the Indonesian highland, has been investigated. In the present experiment 62 cut rose genotypes arisen from cross-breeding in Wageningen (The Netherlands) in 1995, were studied on four direct characters: shoot length, thorniness, flower diameter and petal number, in two physiological stages in two locations. Viz., as adult seedlings in Wageningen in 1996, and as clones onto Natal Briar in Wageningen and Cipanas (Indonesia) in 1997. Taking the adult seedling in Wageningen as a starting point, clonal shoots were significantly longer in Wageningen, but shorter in Cipanas. Thorniness of clonal shoots in Wageningen did not differ significantly, but those in Cipanas were significantly thornier. Flower diameter of clones in Wageningen was significantly larger, but significantly smaller in Cipanas. Number of petals did not differ in Wageningen clones, but those in Cipanas had significantly fewer petals. Despite differences in the level of expression, genotype-location interaction was absent for the characters observed. Various differences in the way of cultivation, in light quantity and in temperature levels are known factors to affect expression of genotypes. It is probable, however, that UV-B exerts most prominent effects in the tropical mountains. If present selection procedure should be maintained, selection in the temperate zone for long shoots, few thorns and large well-filled flowers should be more emphasized. Growing seedlings in a phytotron, simulating the tropical mountainous conditions, seems very