Plants comprising a low copy number of Ri genes

A plant comprising, in the genome thereof, at least 1 but no more than 5 copies of all the genes present on the Ri plasmid, obtained by the method comprising the steps of:

• (a) transforming tissue of the wild type plant with the Ri plasmid of Agrobacterium rhizogenes,
• (b) allowing the transformed tissue to develop roots having a hairy phenotype,
• (c) selecting, among the roots with hairy phenotype of step (b), a root where the hairy phenotype shows a maximum root hair length of at most half of the maximum root hair length observed in the roots obtained in step (b);
• (d) growing the selected root on a regeneration medium and allowing a transformed rooted plantlet to generate from the said selected root;
• (e) growing said transformed rooted plantlet into a mature transformed mother plant having a height of 25-75% of that of the corresponding wild type plant of step (a) and having not less than 80% of the number of flowers of the corresponding wild type plant of step (a);
• and
• (f) optionally, generating progeny of said plant of (e).

A plant comprising, in the genome thereof, at least 1 but no more than 5 copies of all the genes present on the Ri plasmid, obtained by the method comprising the steps of:

• (a) transforming tissue of the wild type plant with the Ri plasmid of Agrobacterium rhizogenes,
• (b) allowing the transformed tissue to develop roots having a hairy phenotype,
• (c) selecting a putatively transformed root having a hairy root phenotype;
• (d) growing the selected root on a regeneration medium and allowing a transformed rooted plantlet to generate from the said selected root;
• (e) growing said transformed rooted plantlet into a mature transformed mother plant;
• (f) generating progeny of the mature transformed mother plant of step (e) by crossing, backcrossing and selfing, while selecting for progeny having an increased height as compared to the mature transformed mother plant of step (e) and a reduced height as compared to that of the corresponding wild type plant of step (a), and
• (g) repeating step (f) until the progeny results in mature plants having a height of 25-75% of that of the corresponding wild type plant of step (a) and having not less than 80% of the number of flowers of the corresponding wild type plant of step (a), and having in the genome thereof, at least 1 but no more than 5 copies of the Ri plasmid.