TY  - BOOK
AU  - Tan H
AU  - Khoo S K
AU  - Ong S H
TI  - Selection of advanced polycross progenies in Hevea improvement
PY  - 1996///
PB  - Journal of Natural Rubber Research
KW  - Hevea
KW  - Ortet selection
KW  - Pollination
KW  - Seed garden
N2  - This paper reviews the progress made in the ortet(mother-tree) selection programme in Hevea improvement carried out at RRI Malaysia. Since the 1970s, a concerted search for promising ortets from a population of 1.3 x 10 6 seedlings derived from advanced polycross seed gardens viz. PBIG and PBFP trials, in the commercial plantations of Peninsular Malaysia has been made. Out of this sample, a total of 2613 genotypes (seedlings) has been selected for further test. Of the 1289 genotypes tested in the three field nurseries with two control cones PR 255 and RRIM 600, 34.1;showed a mean yield which were equal or higher than the former while 59.7;showed equal or higher yields than the latter. In the first series of the selection, which was tested in large scale clone trials, a number of ortet materials showeed yield levels higher than the control RRIM  600. Some of them had equal or higher mean yields than clones of the RRIM 800 series and promotion plot clones in adjacent fields. These results imply that selection of advanced polycross progenies (ortet selection) can be useful complement to the normal hand (controlled) pollination programme in Hevea improvement
ER  -