Abstract:

In this study, association analyses between leaf autumn senescence and single nucleotide polymorphisms (SNPs) derived from amino acid change in the genes of photoperiod pathway of Populus tremula were conducted by linkage disequilibrium mapping (LD mapping) with naturally regenerated aspen populations. The results showed that nucleotide transition between A and G in the 291 nucleotide loci of Phytochrome A gene led to significant variation in autumn senescence index among the three genotypes of AA, AG and GG. The variance P-value between the three genotypes was 0.018 and the Bonferroni adjusted P-value became 0.04; No significant linear correlation was detected between all the selected SNPs in the candidate genes of photoperiod pathway and the senescence duration; Values of the same genotypes in the 291 nucleotide loci of Phytochrome A gene demonstrated significant variance in the starting day of senescence. But the Bonferroni adjusted P-value was more than 0.05, which indicated no significant variance existed between the senescence starting days of the three genotypes, which suggested the complication in regulating senescence starting day during autumn senescence in Europe aspen.

Key words: Populus tremula, leaf autumn senescence, candidate genes, single nucleotide polymorphism, association analysis