Methods of determining sensitivity to photoperiod in cannabis

A method for producing a Cannabis plant having a day length neutral phenotype, or carrying a trait for a day length neutral phenotype, the method comprising:

• producing a Cannabis plant having a day length neutral phenotype, comprising:
• first, performing a cross of a first parent having at least one allele associated with a day length neutral phenotype, with a second parent that has a day length sensitive phenotype, to produce a first progeny plant,
• second, identifying a first progeny plant from the first cross that has the day length neutral phenotype, or that is a carrier of a trait for the day length neutral phenotype,
• third, performing a cross of a first progeny plant that has the day length neutral phenotype, or that is a carrier of a trait for the day length neutral phenotype, with a second first progeny plant that has the day length neutral phenotype, or that is a carrier of a trait for the day length neutral phenotype, to produce a second progeny plant, and
• identifying a Cannabis plant having a day length neutral phenotype or carrying a trait for a day length neutral phenotype, comprising testing nucleic acid from the Cannabis plant to determine the presence or absence of an allele,
• wherein the allele is in linkage disequilibrium r2=0.9 to 1 with a variation in a polymorphic site in the endogenous UPF2 gene
• wherein the variation in a polymorphic site in the endogenous UPF2 gene corresponds to a polynucleotide with a sequence as set forth in SEQ ID NO:
• 2, and wherein the absence of SEQ ID NO:
• 2 or a portion thereof from the endogenous UPF2 gene is associated with the day length neutral phenotype, and
• wherein the presence of the allele indicates that the plant has a day length neutral phenotype or is a carrier of the trait for the day length neutral phenotype.