BREEDING AND VARIETAL IMPROVEMENT OF TROPICAL FRUITS AT MARDI

Y.K. Chan
The breeding and varietal improvement of tropical fruits was discussed in the light of the breeding strategies used and achievement obtained at the Malaysia Agricultural Research and Development Institute (MARDI).

The first step in the breeding programme, to many an understatement, but nevertheless of foremost importance, is to set priorities and objectives clearly. There are more than 150 tropical fruit species and at MARDI, focus is given only to 16 that have the best potential. The clientele's preference of the fruit characteristics must be known through product specification studies so that breeding objectives become clear. Such studies, however, must be intelligent enough to predict the preferences some time in the future to take into consideration the time gap required for varietal development.

The fruit collection and germplasm centres for fruits should be established to provide breeders with the basic resource i.e. genetic variation for crop improvement. These must be evaluated, characterized and comprehensively documented to provide the genetic inventory for breeding research. There are, at present, 3 major centres for fruit germplasm in MARDI i.e. Serdang, Kemaman and Bukit Tangga and evaluation and characterization for some fruits notably banana, papaya, citrus, durian, starfruit, ciku and mango have been completed.

The breeding strategies adopted for clonally and seed propagated fruit species were different. For clonally propagated fruit species, the main strategy was to identify and select promising maternal trees and testing them over time and space to establish their 'repeatibility' (adaptability) of their performance. The success of this strategy depends on the existing variation which may be indigenous or generated through hybridization or recombination. Since in many cases the propagation requires the use of rootstocks, the breeding programme should also take into consideration their influence and suitability to the scion variety.

For seed propagated fruit species such as papaya and watermelon, the breeding methodologies used were backcrossing for improving specific charactics and development of F1 hybrids to exploit heterosis in self-pollinated varieties. For open pollinated varieties, selection and random intercrossing and bulking of seeds provide a quick method to develop varieties.

Chan, Y.K. (1992). BREEDING AND VARIETAL IMPROVEMENT OF TROPICAL FRUITS AT MARDI. Acta Hortic. 321, 138-151
DOI: 10.17660/ActaHortic.1992.321.13
https://doi.org/10.17660/ActaHortic.1992.321.13

Acta Horticulturae