Lettuce breeding method

Abstract

Methods for pollinating lettuce and producing hybrid lettuce seed are described. The methods include the steps of providing lettuce plants and releasing Megachile rotundata bees or attracting pollinators. Hybrid lettuce seeds and plants produced using methods of this invention and male sterile lettuce lines used in this invention are also described.

1 . A hybrid lettuce seed resulting from a cross between a first lettuce plant comprising pollen and an emasculated or male sterile lettuce plant, wherein said cross is performed by a process comprising the steps of:
 a) releasing  Megachile  bees, wherein said bees transfer pollen from said first lettuce plant to said emasculated or male sterile lettuce plant to form a pollinated lettuce plant; and   b) growing said pollinated lettuce plant to produce hybrid lettuce seed.   
   
   
       2 . The hybrid lettuce seed of  claim 1 , wherein said seed produces a plant having average head weight greater than the average head weight of the first lettuce plant. 
   
   
       3 . The hybrid lettuce seed of  claim 1 , wherein said  Megachile  bees are selected from the group consisting of:  Megachile rotundata, Megachile relativa , and  Megachile pugnata  bees. 
   
   
       4 . The hybrid lettuce seed of  claim 1 , wherein said  Megachile  bees are  Megachile rotundata  bees. 
   
   
       5 . The hybrid lettuce seed of  claim 1 , wherein said first lettuce plant is an inbred or F1 lettuce plant. 
   
   
       6 . The hybrid lettuce seed of  claim 5 , wherein providing said inbred or F1 lettuce plant comprises planting seed of said inbred or F1 lettuce plant wherein said seed germinates and grows into said inbred or F1 lettuce plant. 
   
   
       7 . The hybrid lettuce seed of  claim 1  wherein said male sterile lettuce plant is a lettuce plant that does not produce pollen. 
   
   
       8 . The hybrid lettuce seed of  claim 7 , wherein providing said male sterile lettuce plant comprises planting seed of said male sterile lettuce plant wherein said seed germinates and grows into said male sterile lettuce plant. 
   
   
       9 . The hybrid lettuce seed of  claim 1 , wherein said emasculated lettuce plant is a plant comprising flowers with anthers wherein said plant is emasculated by removing the anthers or by misting. 
   
   
       10 . The hybrid lettuce seed of  claim 1 , wherein said step of releasing is performed in an open field. 
   
   
       11 . The hybrid lettuce seed of  claim 1 , wherein said step of releasing is performed in an enclosed or caged area. 
   
   
       12 . The hybrid lettuce seed of  claim 1 , wherein said first lettuce plant and said emasculated or male sterile plant flower during a flowering period, wherein said releasing step is performed by releasing a batch of bees on a weekly basis during the flowering period. 
   
   
       13 . The hybrid lettuce seed of  claim 1 , wherein said step of releasing is performed at a temperature of at least about 74° F. 
   
   
       14 . The hybrid lettuce seed of  claim 1 , wherein said lettuce plants are  Lactuca sativa  or  Lactuca serriola  species.