Production of hybrid lactuca sativa seeds

Abstract

The present invention concerns hybrid Lactuca sativa seeds which have a male sterile genotype and which are heterozygous for at least one distinct gene which provides plants derived from said seeds with a distinct phenotype. The invention also concerns a method for producing hybrid Lactuca sativa seeds, comprising a step for culture, in an enclosed medium, of phenotypically male sterile plants and phenotypcally male fertile plants, a step for pollinization by diptera introduced into the closed medium upon flowering of the plants, and a step for harvesting the seeds produced by the male sterile plants.

1 . A hybrid  Lactuca sativa  seed, characterized in that it:
 a. has a male sterile genotype; and   b. is heterozygous for at least one distinct gene, providing the plant derived from said seed with a detectable phenotype.   
     
     
         2 . The seed according to  claim 1 , wherein said male sterile genotype involves at least one nuclear gene and wherein said seed is heterozygous for the gene or genes at the origin of male sterility. 
     
     
         3 . The seed according to  claim 2 , wherein the male sterility is monogenic. 
     
     
         4 . The seed according to  claim 3 , wherein the gene for male sterility is dominant. 
     
     
         5 . The seed according to  claim 1 , wherein said male sterile genotype is provided by the Ms7 sterility gene. 
     
     
         6 . The seed according to  claim 1 , characterized in that its genome comprises a double strand DNA sequence of 650 to 700 nucleotides wherein the 5′ ends of each of the two strands commence with the sequence 5′ TGCGTTCCAC 3′ (SEQ ID NO: 1). 
     
     
         7 . The seed according to  claim 1 , wherein said phenotype is a phenotype of agricultural interest. 
     
     
         8 . The seed according to  claim 7 , wherein said phenotype is provided by a gene for standard or intermediate resistance to an infection by a virus, a bacterium, an insect or a fungus. 
     
     
         9 . The seed according to  claim 8 , wherein said phenotype is a standard or intermediate resistance to one of the following fungi:  Bremia lactucae, Fusarium oxysporum, Sclerotinia minor  or  sclerotorum, Botrytis cinerea, Rhizictonia solani, Microdochium panattonianum, Verticiulium dahliae, Erysiphe chicocearum  or  Pithium tracheiphilum , to one of the following insects:  Nasonovia ribisnigri, Myzus persicae, Macrosiphum euphorbia, Nematodes pratylenchus  or  meloidogyne , the leafminers liriomyza huidobrensis or  Pemphigus busarius , to one of the following bacteria: pseudomonas, xanthomonas or rhizomonas, or to one of the following viruses: LMV, TSWV, “Big vein”, TBSV, LNSV, TuMV, CMV or BWYV. 
     
     
         10 . The seed according to  claim 8 , wherein said seed presents a second distinct gene for standard or intermediate resistance, in the heterozygous form. 
     
     
         11 . The seed according to  claim 8  or  claim 10 , wherein said standard or intermediate resistance genes are selected from the following genes for resistance to bremia: Dm10, R17, Dm5/Dm8, R36/R37 (cluster 1), Dm1, Dm2, Dm3, Dm6, Dm14, Dm15, Dm16, Dm18 (cluster 2), or Dm4 Dm7, Dm11, R38 (cluster 4); or the Tu gene for resistance to TuMV (cluster 1); the Nr gene for resistance to Nasonovia (cluster 2); or the genes mol 1 mol 2 for resistance to LMV (cluster 4). 
     
     
         12 . A hybrid  Lactuca sativa  plant, characterized in that it:
 a. has a heterozygous male sterile genotype; and   b. is heterozygous for at least one distinct gene, providing it with a detectable phenotype.   
     
     
         13 . The plant according to  claim 12 , wherein said male sterile genotype is of nuclear origin and wherein said plant is heterozygous for the gene or genes at the origin of male sterility. 
     
     
         14 . The plant according to  claim 13 , wherein the male sterility is monogenic. 
     
     
         15 . The plant according to  claim 14 , wherein the gene for male sterility is dominant. 
     
     
         16 . The plant according to  claim 12 , wherein said male sterile genotype is provided by the gene for sterility, Ms7. 
     
     
         17 . A cell from a hybrid  Lactuca sativa  plant, characterized in that it:
 a. has a heterozygous male sterile genotype; and   b. is heterozygous for at least one distinct gene, providing it with a phenotype which is detectable in the plant.   
     
     
         18 . The cell according to  claim 17 , wherein said male sterile genotype is of nuclear origin and said cell is heterozygous for the gene or genes at the origin of male sterility. 
     
     
         19 . The cell according to  claim 18 , wherein the male sterility if monogenic. 
     
     
         20 . The cell according to  claim 19 , wherein the gene for male sterility is dominant. 
     
     
         21 . The cell according to  claim 17 , wherein said male sterile genotype is provided by the Ms7 sterility gene. 
     
     
         22 . A population of seeds, wherein said population comprises at least 10 5  seeds according to  claim 1 . 
     
     
         23 . (canceled) 
     
     
         24 . A population of  Lactuca sativa  seeds comprising at least 40% of seeds according to  claim 1 . 
     
     
         25 . The population according to  claim 24 , wherein the other seeds do not comprise the male sterility gene. 
     
     
         26 - 47 . (canceled)