Résumé
The planting material is one of the most critical technological components influencing the productivity of rubber (Hevea brasiliensis) plantations. The Indonesian Rubber Research Institute (IRRI) continuously conducts breeding program to develop new superior rubber clones possessing vigorous growth, high latex yield, disease resistance and drought tolerance. The Institute has released IRR 00, 100 and 200 series clones, and is currently evaluating the promising IRR 300, 400 and 500 series under different agro-climatic conditions Conventionally, development of rubber clones involve multiple evaluation stages, including the seedling evaluation trial (SET), small-scale clone trial (SSCT) large-scale clone trial (LSCT) and multilocation trial, taking more than 25 years before a clone can be recommended for commercial planting. In order to accelerate this process, IRRI has introduced the New Phenotyping Method (NPM), which streamlines the conventional evaluation stages by bypassing the SET stage and directly evaluating F1 progenies in the SSCT aiming to reduce the length of breeding cycle. Unlike the SET, where each genotype is represented by only one tree, the NPM employs replicated SSCT trials to improve accuracy and representativeness of each genotype. This modification is expected to shorten the selection period by 5-10 years compared to the conventional approach although it requires a larger research area. In this study, 202 F1 progenies and 8 commercial clones (as control) were planted in five replications with two plants per genotype per replication. Growth performance, yield potential under different tapping systems, resistance to main diseases especially to Pestalotiopsis leaf fall disease, clone typology, tapping panel dryness (TPD) incidence, and drought tolerance were assessed during immature (4 year) and mature period (2 -year). Based on observations of all parameters, 10 of the best genotypes were selected. These selected genotypes have a high latex yield potential and good agronomic characteristics, such as rapid growth, disease resistance, as well as tolerance to TPD and drought. The best genotypes were named IRR 500 series, and will subsequently under large-scale clone trial and multilocation trials. In addition, the NPM demonstrates a promising approach to accelerate rubber clone development while maintaining selection reliability and adaptability across environments.