Shortening the selection process in Mauritius
| MSI99P3062 | |
| Mamet, L. D. | |
| Shortening the selection process in Mauritius | |
| Abstracts - 4th ISSCT Breeding and Germplasm Workshop: efficiency of sugr cane breeding, 18-22 May 1988, Hotel Coralia Mont Choisy, Mauritius | |
| book chapter | |
| 1998 | |
| p. 30 | |
| Réduit: Mauritius Sugar Industry Research Institute | |
| En | |
| En | |
| It was highly desirable to shorten the preliminary phase of the selection process for sugar cane in Mauritius in order to improve efficiency. Selection for ratooning ability is of major importance as, on average, six to seven ratoon crops are grown commercially. The selection process previously lasted from 14 to 18 years. Ratooning ability was tested on five occasions in the programme and this was considered to be excessive. It was hypothesized that 1st ratoon data (1 R) in stage 3 (single lines) and 2nd ratoon (2R) in stage 4 (double lines) were not cost effective and that the cycle could be shortened by two years without loss of precision. Historical data (estimates of sucrose content, cane and sugar yields) from the MSIRI selection trials planted between 1986 and 1990, representing 9680 genotypes (85 trials) in stage 3 (one-line stage) and 2620 genotypes (141 trials) in stage 4 (two-line stage), were analysed. Repeatability estimates (phenotypic correlations), between plant cane (PC) and the mean of PC and IR (Pl) in stage 3 and between P1 and the mean of plant cane, 1st and 2nd ratoon (P12) in stage 4, were found to be positive and highly significant for all characters indicating that the extra ratoon data were unnecessary. The proposed selection scenarios were further studied using differential- selection methodology. The coincidence indices (CI) obtained between the old and the new scenarios were extremely high (63-82percent in stage 3 and 91-96percent in stage 4) again indicating that the additional ratoon data were effectively redundant. Realized gains from selection in stage 4 based on P12 as opposed to P1 were shown to be small or even negative. The results concurred extremely well with published findings from Australia and the USA. It was concluded that resources could be more usefully allocated to test genotypes over more sites and more replicates and that the cycle be reduced by two years. | |
| SUGARCANE SELECTION SELECTION METHODS BREEDING | |
| MAURITIUS | |
| Cane breeding and genetics | |
| Selection: policies and methods | |
| 1998-06-29 | |
| En | |
| LIB | |
| CAT | |
| 1 | |
| PB |