LpBRI1 polymorphism association with flag leaf architecture in perennial ryegrass

In order to evaluate association between sequence polymorphism in candidate genes and phenotypic traits in perennial ryegrass (Lolium perenne L.), mapping population, consisting of 96 genotypes, was assessed for traits related to seed yield with four replications over two years. The traits flag leaf length and width, inflorescence length, spikelet number, seed weight per plant, seed weight per inflorescence, 1000 seed weight and heading date revealed heritability ranging from 0.14 to 0.84 and considerable amount of variation. Marker-trait associations were studied between sequence polymorphism of five candidate genes LpIAA1, LpRUB1, LpBRI1, LpSHOOT1 and LpTB1 with putative function in plant architecture and phenotypic traits. Thirteen marker-trait associations were identified in total. Relation between 3 bp INDEL polymorphism in 3'UTR region of LpBRI1 gene and flag leaf width was confirmed in two consecutive years of field experiment. The possible regulatory role of the identified INDEL is discussed.