| 000 | 03522nam a22004337a 4500 | ||
|---|---|---|---|
| 001 | G66400 | ||
| 003 | MX-TxCIM | ||
| 005 | 20240919021051.0 | ||
| 008 | 121211s ||||f| 0 p|p||0|| | | ||
| 020 | _a968-6923-94-2 | ||
| 040 | _aMX-TxCIM | ||
| 072 | 0 | _aF30 | |
| 072 | 0 | _aH20 | |
| 082 | 0 | 4 |
_a632.4 _bDUB |
| 110 | 2 | _aCentro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT), Mexico DF (Mexico) | |
| 100 | 1 |
_aSingh, R.P. _gGlobal Wheat Program _8INT0610 _9825 |
|
| 245 | 0 | 0 | _aBreeding strategies for introgressing diverse scab resistances into adapted wheats |
| 260 |
_aMexico, DF (Mexico) _bCIMMYT : _c1997 |
||
| 340 | _aPrinted | ||
| 520 | _aScab of wheat, caused by Fusarium spp., is a major constraint in the humid and semi- humid wheat production areas of many countries. The progress in breeding resistant cultivars at CIMMYT and elsewhere has been slow because most known resistances occur in unadapted germplasm, and the resistances are usually quantitative and based on the additive interactions of a few to several minor genes. Three breeding strategies which may enhance the introgression and accumulation of minor genes into adapted wheats are proposed. In the first scheme, the F1 hybrids are developed by crossing two diverse, scab resistant wheats, eg., Ning 7840 from China and Frontana from Brazil. The F1 hybrids are then top-crossed (three-way) with a third parent which is adapted to the target area but may lack adequate scab resistance. A large (between 1000-2000 plants) top-cross population is required to obtain sufficient plants with all four or five minor genes in a heterozygous condition. We propose to either apply only mild selection pressure, or no selection pressure, for scab resistance in early segregating generations (such as F1-top, F2, and F3). However, in the meantime, strong selection pressure must be applied in these early generations for desirable agronomic attributes and resistance to other diseases such as rusts. The selected plants could be maintained as bulk and a large population size should be maintained in each generation. Intense selection pressure for scab resistance should be applied in the later (F4 and F5) generations, when the level of homozygosity is higher, in order to identify a few transgressive segregants having good agronomic type and four to five genes combined for fusarium resistance. A large number of selected F5 plants could be harvested in a pedigree fashion to achieve pure F6 lines, which could be further assessed for resistance to fusarium. The two alternative strategies, which will reduce the population size in segregating generations, will require breeding in two steps: first, parent building; and second, transferring resistance into adapted wheats. The proposed strategies should result in the introgression of additive minor genes in an adapted background. | ||
| 536 | _aGlobal Wheat Program | ||
| 546 | _aEnglish | ||
| 591 | _aR97-98PROCE|9806|AGRIS 9802|anterior|R98PROCE|FINAL9798 | ||
| 593 | _aJose Juan Caballero | ||
| 594 | _aINT0610 | ||
| 595 | _aCPC | ||
| 650 | 1 | 7 |
_aDisease resistance _gAGROVOC _2 _91077 |
| 650 | 1 | 0 |
_aFusarium _92705 |
| 650 | 1 | 0 | _aHybridization |
| 650 | 1 | 0 | _aIntrogression |
| 650 | 1 | 7 |
_aPlant diseases _gAGROVOC _2 _91206 |
| 650 | 1 | 0 |
_aPlant production _91212 |
| 653 | 0 | _aCIMMYT | |
| 650 | 1 | 7 |
_aTriticum _gAGROVOC _2 _91295 |
| 650 | 1 | 7 |
_aPlant breeding _gAGROVOC _2 _91203 |
| 700 | 1 |
_aDubin, H.J.|Gilchrist, L.|Reeves, J.|McNab, A. _eeds. |
|
| 700 | 1 |
_997 _aGinkel, M. Van |
|
| 942 | _cPRO | ||
| 999 |
_c3881 _d3881 |
||