Method of obtaining female inbred lines from asteracea hybrids
AssigneeEmpresa Brasileira De Pesquisa Agropecuaria-Embrap
InventorsClaudio Guilherme Portela De Carvalho, Jose Francisco Ferraz De Toledo
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Abstract
The present invention presents a method for obtaining female inbred lines from Asteracea hybrids, using the species Helianthus annuus as a model The method of the invention is based on the modification of lines with the fertility restorer gene (Rf), obtained from self-pollination of hybrids, in lines presenting normal cytoplasm and not containing the Rf gene. Further, derived male sterile lines were developed. Through the use of this methodology it was possible to obtain female lines from commercial hybrids of sunflower.
Claims15
1-13. (canceled)
A method of obtaining female inbred lines from Asteraceae hybrids, wherein said lines are obtained by alteration of RHA inbred lines, obtained from the self pollination of hybrids (commercial or non-commercial), into HA inbred lines in order to modify these HA lines into male sterile plants, said method comprising the following steps:
- (a) crossing an HA inbred line from Asteraceae (non-recurrent line), previously emasculated (or subjected to previous pollen sterilization through the use of chemical agents or other mechanisms), with an RHA inbred line (recurrent line) carrying the fertility restorer gene (Rf);
- (b) generating F1 plants, containing 50% of the genotype of the recurrent line of step (a);
- (c) backcrossing the Fl plants, previously emasculated (or subjected to previous pollen sterilization through the use of chemical agents or other mechanisms), with the recurrent line of step (a);
- (d) obtaining backcross 1 (BC1) plants, containing 75% of the genotype of the recurrent line of step (a);
- (e) identifying with respect to the fertility restorer gene (Rf) the heterozygotes (Rfrf) and homozygotes (RfRf) in the BC1 generation obtained in step (d);
- (f) backcrossing BC 1 heterozygote (Rfrf) and homozygote (RfRf) plants, previously emasculated (or subjected to previous pollen sterilization through the use of chemical agents or other mechanisms), with the recurrent line of step (a), in order to obtain BC2 plants, wherein only seed of BC1 heterozygote plants proceed to the next generation;
- (g) obtaining BCn plants from the BCn−1 plants, according to steps (e) and (f);
- (h) after successive backcrossings in steps (e) to (g), identifying and selfing the heterozygotes (Rfrf) and the homozygotes (RfRf) of the BCn generation obtained in the step (g), wherein by the selfing of Rfrf plants of the BC. generation HA plants (N rfrf) and RHA plants (N RfRf and N Rfrf) are obtained;
- (i) identifying and selfing HA plants (N rfrf) and RHA plants (N RfRf and N Rfrf) obtained by selfing of Rfrf plants in step (h);
- and
- (j) altering an HA plant (N rfrf) obtained in step (h) into a male sterile plant, after successive backcrossings, wherein the non-recurrent line is any plant presenting cytoplasmic male sterility and the recurrent line is the HA line (N rfrf), wherein the F1 generation is obtained by the identification of HA plants in step (i).
Dependencies are inferred from the claim text.