The development of a drought-tolerant maize composite variety for Rodrigues
| MSI05P4164 | |
| Govinden, N. | |
| The development of a drought-tolerant maize composite variety for Rodrigues | |
| Lalouette, J. A., Bheenick, K. J. and Nundalallee, C. (eds), Proceedings, Seventh Meeting of Agricultural Scientists, 4-6 May 2005, Boname Hall, MSIRI, Mauritius. (Draft) | |
| 7th Meeting of Agricultural Scientists, Mauritius, 4-6 May 2005 | |
| book chapter | |
| 2005 | |
| p. 187-192 | |
| Réduit: Food and Agricultural Research Council | |
| In: Book of Abstracts. Seventh Meeting of Agricultural Scientists, 4-6 May 2005, Boname Hall, MSIRI, Réduit, Mauritius. p 34 (Proceedings available at http://www.gov.mu/portal/sites/ncb/moa/farc/amas2005/pdf/MAS20051stDraft.pdf) | |
| En | |
| En | |
| Maize is still a very important crop in Rodrigues although its production has regressed dramatically in the past decade. The regression is due to several causes including low yield, which is itself due in part to drought. A research project was therefore undertaken from 1998 to 2003 to breed a drought-tolerant variety. The procedure involved first hybridizing MSIRI 3B, the most widely planted variety, with a drought-tolerant donor from the International Maize and Wheat Improvement Centre (CIMMYT). This was followed by four cycles of selection and backcrossing to MSIRI 3B, the recurrent parent, to recover its useful traits such as preferred kernel characteristics and resistance to Maize Streak Virus. The population was grown under controlled drought in plastic rain-out shelters, and selection was practised for short anthesis-silking intervals (ASI), a proxy for drought tolerance. Four cycles of mass-selection then followed in order to recombine and concentrate drought tolerance genes. Thus, after eight cycles of crossing and selection, a new population was developed. It has been named MSIRI 3C. MSIRI 3C was evaluated in replicated yield trials in Mauritius and Rodrigues. In the absence of drought in the rainy season in Mauritius and Rodrigues, MSIRI 3C was marginally higher in yield than MSIRI 3B, by an average of 14 per cent in 6 trials. Under severe drought conditions in Mauritius, the yield of MSIRI 3C was better than that of MSIRI 3B by 125 per cent in one trial and by 74 per cent in another. In the latter trial its yield was not significantly different from some of the best drought-tolerant varieties from CIMMYT. All the 13 field trials laid down in Rodrigues in the 2003 main planting season to evaluate drought tolerance were destroyed by a cyclone and no results were obtained. More trials were planted in 2004 but the results were compromised by rain. Two indirect consequences of selection have been observed in the new variety. Firstly, under drought, but not under humid conditions, MSIRI 3C matures slightly earlier, by about one week, than MSIRI 3B. Secondly, it has a large proportion of stay-green plants. At ear maturity, such plants have several green leaves. They are useful in areas such as Rodrigues where growers often feed maize stover to livestock. The kernels of MSIRI 3C are orange-yellow and flint, as is preferred in Rodrigues. Seeds were produced and distributed to growers at the end of 2003 and at the beginning of 2004. Early reports indicate good acceptance of the variety by growers in Rodrigues. | |
| Maize varieties drought tolerance physiology | |
| Rodrigues | |
| Maize | |
| Genetics and breeding: Breeding for biotic stress | |
| 2005-05-03 | |
| En | |
| LIST | |
| FC |