000			02455nam a22001817a 4500
100			_aClement, K.
245			_aIRRDB multilateral clone exchange (MCE-2015, Hevea brasiliensis): Status report on the experimentation set up in GREL estate, Ghana
260			_bProceedings of the IRRDB International Rubber Conference 2023, 20-21 February 2023, IRRDB, Kuala Lumpur, Malaysia, pp. 17-27.
520			_aThe IRRDB MCE (Multilateral Exchange of Clones Program) is aimed to make available to all participants a common 44 rubber clones, to evaluate them in different environmental conditions and share the results. This communication reports on the preliminary results from the field experimentation set up in GREL-Ghana in October 2021 by Michelin and CIRAD, with the support of SIPH, on 36 IRRDB MCE clones and five control clones. Unfortunately, the clone Reyan 7-20-59 was affected by leaf diseases in the budwood garden, thus could not be multiplied in due time for field planting. Difficulties were also faced at nursery level for the clone RRISL 208. The field experimental design is a ﻬ balanced D-optimal incomplete block design, with 16 blocks of 10 clonal plots, with a total of 160 plots for 40 clones ( 4 replications of 10 trees per clone). During the first year in the field, a few clones showed minor symptoms of Corynespora infection. In October 2022, at 1-year of age, the leaves of some clones turned yellowish (RRIT 251, Hongshan 67-15, RRIT 408, RRIT 3604 and RRIT 226); beginning 2023, the symptom became evident in other clones in the budwood garden and trial plots. Among the 1600 initial plants, a total of 1581 trees survived at 1 year of age (99%). However, out of 160 plots, 14 plots were discarded from the analyses due to genetic pollution, thus the number of studied clones was reduced to 38. A ranking of these 38 clones are presented based on trunk girth at five months (G5m) and 12 months (G12m) after planting. For G12m, the girth varied from 8.35 cm (IRCA 825) to 3.83 cm (RRISL 208). The five most vigorous clones were IRCA 825, RRII 430, IRCA 41, PB 260 and Reyan 7-33-97.
650			_aBreeding and genetics
650			_aClonal selection
650			_aMultilateral clone exchange
650			_aExperimental design
650			_aImmature growth
650			_aGenetic checking
700			_aFlorian, D., Gregory, L., Eric, C., Thierry, C., Aurelie, D., Dominique, G., Andre, C.D. and Laurent, V.
942			_cJS
999			_c75214 _d75214