Isozyme analysis supports allotetraploid inheritance in tetraploid creeping bentgrass (Agrostis palustris Huds.)

Abstract

Inheritance data from tetraploid Agrostis palustris Huds. populations produced by crossing selected plants from cultivated creeping bentgrass varieties is reported. Phosphoglucose isomerase, phosphoglucomutase, glutamate oxaloacetate transaminase, triosphosphate isomerase, anodal peroxidase, esterase, and alcohol dehydrogenase were resolved in a Tris-citrate/lithium-borate pH 8.3 buffer system. Acid phosphatase, 6-phosphogluconate dehydrogenase, aconitase, malate dehydrogenase (MDH), and shikimic acid dehydrogenase were resolved in a histidine-citrate pH 5.7 buffer system. Four enzyme systems exhibiting polymorphism in the Tris-citrate/lithium-borate buffer system were selected for further genetics studies. Segregation data at the Tpi-1, Tpi-2, Got-2, Pgi-2, and Pgm-2 loci were used to identify allozymes and distinguish between allo- or autotetraploid segregation patterns. Two allozymes were identified at the Pgm-2 and Tpi-1 loci, while three allozymes were identified at the Got-2 and Tpi-2 loci. The Pgi-2 locus was highly polymorphic with six different allozymes identified. Fixed heterozygosity at the Tpi-2 and Got-2 loci and disomic segregation for a tetra-allelic individual at the Pgi-2 locus provided strong genetic evidence to support allotetraploid inheritance in creeping bentgrass. Additionally, one parental clone that exhibited high levels of self-fertility was identified and its breeding implications are discussed.