An evaluation of new designs for the first clonal stage of selection of the MSIRI sugar cane development program
| MSI09P4447 | |
| Ramdoyal, K. Santchurn, D. Ramnawaz, C. Mungur, H. | |
| An evaluation of new designs for the first clonal stage of selection of the MSIRI sugar cane development program | |
| [Programme and Abstracts]. 9th ISSCT Breeding and Germplasm workshop "Sugarcane Crop Improvement: Opportunities and Challenges", 17-21 August, 2009, Cairns, Australia | |
| book chapter | |
| 2009 | |
| p. 31 | |
| En | |
| EN | |
| The conventional design used at the first clonal (2-m plots) stage of selection trials at MSIRI is based on a systematic arrangement of control varieties after every 5-6 rows of test genotypes in a line and column design. Field Brix measured on the controls, are analyzed to estimate variability of the field within sub-trials and selection is based on the significance of the rows and columns components in the analysis of variance, in addition to vigour and visual grade. New designs have been developed to allow genotype yields to be adjusted for field variation in two dimensions while using a reduced number of plots as check varieties. The basic idea is to repeat control varieties several times in a standard design. In this context, an Augmented Latin Square (ALS) design was superimposed on the conventional layout at the first clonal (2-m plot) stage with 366 test varieties evaluated in three sub-trials. The ALS design also accommodated a second control variety of wide adaptation with similar ripening pattern as the standard control. Analysis and selection was carried out in plant cane crop using a uniform selection pressure on Brix probability with respect to the standard varieties for both designs within vigour codes and a visual appreciation grade. For the ALS, selection simulations were done with one control at a time and on the average of the two control varieties. Results indicated that when comparison was done with the same control, a higher number of clones (66) were selected by the ALS design compared with the conventional one (49). A total of36 genotypes (9.8 per cent ) were selected and 287 (78.4 per cent ) rejected by both designs with a high coincidence index (Cl) of 88 per cent . When selection was based on the average of the two control varieties, a higher proportion of clones were commonly selected and rejected by both designs with a coincidence index of 96 per cent , indicating little disparity in selection efficiency between the two designs. The performance of all genotypes selected by the two designs was further followed at the second clonal stage. Both designs proved to be equally efficient in selecting the best genotypes. Because of its numerous advantages - fewer controls (12-13 per cent ), accommodation of more test varieties, comparison with two controls, economy of land and other resources - the ALS design with two controls has been adopted on a large scale at the 1st clonal stage as from year 2004. However, the conventional one also is used whenever the field layout in the sugarcane breeding program ofMSIRI is inappropriate to accommodate the ALS design | |
| sugarcane varieties experimental designs selection breeding field layout statistical analysis selection process | |
| Mauritius | |
| Cane breeding and Genetics | |
| Selection: Experimental designs | |
| 2009-12-21 | |
| En | |
| PB |