02528nam a2200181 a 450000100080000000500110000800800410001910000170006024500950007726001670017230000140033950001900035352017510054365000100229465000100230470000150231470000170232914682552023-11-03       2005    bl uuuu     u00u1 u    #d1 aANDREOLI, C.  aGenetic control of seed dormancy and preharvest sprouting in wheat.h[electronic resource]  aIn: CONGRESSO BRASILEIRO DE MELHORAMENTO DE PLANTAS, 3., 2005, Gramado. Anais... Passo Fundo: Embrapa Trigo; Sociedade Brasileira de Melhoramento de Plantasc2005  c1 CD-ROM.  aSeção: Área 1 - Espécies Anuais - Resumos: Pdf.1468. Editado por Ana Christina Sagebin Albuquerque, Cláudia de Mori, Edson Iorczeski, João Carlos Haas, Paulo Fernando Bertagnolli.  aPreharvest sprouting (PHS) damage leads to occasional massive losses in all wheat producing areas, causing downgrading of grain quality, that severely limits end-use applications and results in substantial financial losses to farmers and food processors. Red grain color is a traditional marker for resistance to sprouting in wheat breeding programs, however red-grained genotype alone does not always guarantee effective resistance. The objective of this work was to find genes for resistance to seed dormancy (PHS) and its inheritance in Brazilian wheat cultivars. Crosses and its reciprocal of Frontana (a red-grained line with high level of seed dormancy) with OR1 (a red-grain cv. with very low dormancy) were used as recurrent female parent. Genetic variation for dormancy was investigated in the parents, F1 and 300 F2 lines derived from F1 hybrids. The germination/dormancy was evaluated on seeds germinated in paper towel rolls at 20 °C for 5 days. The germination was scored for number of sprouted grains with visible rupture of the pericarp. A bimodal distribution for dormancy occurred in the Frontana/OR1 and OR1/Frontana derived F2 populations. The mean ratio of dormant and nondormant seeds of the cross and its reciprocal was 85:1115, fitting a digenic model of 1:15 (P&lt 0.05). In fact, all F1 non after-ripened seeds germinated. The F2 distribution indicates that dormancy appears to be recessive over non-dormancy and there is the involvement of two major genes controlling seed dormancy, which only the homozygous aabb is dormant. As it was expected, there was no effect of maternal tissues. The RIL´s lines are being produced and the genes will be molecularly characterized in the Biotechnology Laboratory at Embrapa Soja.  aWheat  aTrigo1 aBASSOI, M.1 aBRUNETTA, D.