Chlorosis resistant cytoplasmic male sterile

1 . A method of producing a chlorosis resistant CMS Brassica rapa plant, comprising the steps of:

a) protoplast fusion of protoplasts of a fertile Brassica rapa plant with protoplasts of a CMS Brassica rapa plant as a CMS cytoplasm donor, wherein the cytoplasm donor comprises chloroplasts of a diploid Brassica oleracea plant and Raphanus sativus mitochondria, wherein mitochondria of the CMS cytoplasm donor are combined with chloroplasts and nucleus of the fertile Brassica rapa plant; and

b) selecting a protoplast fusion product, wherein:

i. at least 95% of fusion product chloroplasts are Brassica rapa chloroplasts comprising one or more sequences selected from the group consisting of SEQ ID NO: 1, SEQ ID NO: 3 and SEQ ID NO: 5;

ii. the fusion product nuclear genome is a Brassica rapa nuclear genome comprising SEQ ID NO: 7 and/or SEQ ID NO: 9;

iii. the fusion product does not comprise Brassica oleracea chloroplasts that comprise one or more sequences selected from the group consisting of SEQ ID NO: 2, SEQ ID NO: 4, and SEQ ID NO: 6; and

iv. the fusion product comprises a mitochondrial genome of Raphanus sativus comprising the sequence of SEQ ID NO: 11.

2 . The method of claim 1 , further comprising:

c) crossing the selected fusion product with a wild-type Brassica rapa plant to produce progeny, and selecting from the progeny a CMS Brassica rapa plant that is chlorosis resistant.

3 . The method of claim 1 , wherein the CMS Brassica rapa plant is selected from the group of Brassica rapa subspecies consisting of: Rapa, Pekinensis, Glabra, Chinensis, Rapifera, Oleifera, Parachinensis, Perviridis, Brassica Narinosa, Trilocularis , and Mizuna.

4 . The method of claim 1 , wherein the Brassica rapa subspecies is Rapa or Pekinensis.

5 . The method of claim 1 , wherein the chlorosis resistant CMS Brassica rapa plant is obtainable by growing seeds deposited under NCIMB Accession Number 43622.