Tipburn-resistant lettuce plant, production method for tipburn-resistant lettuce plant, and method for giving lettuce plant tipburn-resistance

A method for giving lettuce plant tipburn-resistance comprising a step of introducing a tipburn-resistance gene locus on the 4th chromosome into a lettuce plant and that a tipburn-resistance gene locus is specified by at least one polynucleotide of followings (a), (b), (c), and (d):

• (a) polynucleotide including polymorphism that a 271576390th cytosine base from a first of the 4th chromosome is thymine base and wherein bases of 50 bp before and after the thymine base make up a base sequence having no less than 80% identity to a base sequence of sequence number 1;
• (b) polynucleotide including polymorphism that a 274188377th cytosine base from a first of the 4th chromosome is thymine base and wherein bases of 50 bp before and after the thymine base make up a base sequence having no less than 80% identity to a base sequence of sequence number 2;
• (c) polynucleotide including polymorphism that a 274188380th thymine base from a first of the 4th chromosome is guanine base and wherein bases of 50 bp before and after the guanine base make up a base sequence having no less than 80% identity to a base sequence of sequence number 3;
• and
• (d) polynucleotide including polymorphism that a 274188382th adenine base from a first of the 4th chromosome is cytosine base and wherein bases of 50 bp before and after the cytosine base make up a base sequence having no less than 80% identity to a base sequence of sequence number 4.

A method for screening a tipburn-resistant lettuce plant is comprising a step of picking up a lettuce plant including a tipburn-resistance gene locus on a 4th chromosome from lettuce plants that have been tested as parents for producing a tipburn-resistant lettuce plant by crossing and that the tipburn-resistance gene locus is specified by at least one polynucleotide of followings (a), (b), (c), and (d):

• (a) polynucleotide including polymorphism that a 271576390th cytosine base from a first of the 4th chromosome is thymine base and wherein bases of 50 bp before and after the thymine base make up a base sequence having no less than 80% identity to a base sequence of sequence number 1;
• (b) polynucleotide including polymorphism that a 274188377th cytosine base from a first of the 4th chromosome is thymine base and wherein bases of 50 bp before and after the thymine base make up a base sequence having no less than 80% identity to a base sequence of sequence number 2;
• (c) polynucleotide including polymorphism that a 274188380th thymine base from a first of the 4th chromosome is guanine base and wherein bases of 50 bp before and after the guanine base make up a base sequence having no less than 80% identity to a base sequence of sequence number 3;
• and
• (d) polynucleotide including polymorphism that a 274188382th adenine base from a first of the 4th chromosome is cytosine base and wherein bases of 50 bp before and after the cytosine base make up a base sequence having no less than 80% identity to a base sequence of sequence number 4.