Submitted to: American Society of Agronomy Branch Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 1/1/1999
Publication Date: N/A
Technical Abstract: This study was undertaken to determine the relationship between dallisgrass and P. pubiflorum. The cytology and reproduction behavior was studied in three P. pubiflorum accessions and their F1 hybrids with P. juergensii (2n=2x=20; JJ), P. intermedium (2n=2x=20; II) and yellow-anthered (2n+4x=40; IIJJ) and Uruguayan (2n=6x=60; IIJJXX) dallisgrass biotypes. All P. pubiflorum accessions were sexual and had 60 chromosomes that paire as 30 II. The yellow-anthered x P. pubiflorum hybrids had 50 chromosomes with a mean pairing behavior of 36.6 I + 8.7 II indicating that one P. pubiflorum genome is homologous with either the I or J genome. The P. pubiflorum x P juergensii and P. pubiflorum x P. intermedium hybrids had 40 chromosomes with 24.1 I + 8.0 II + 0.1 III and 35.3 I + 2.4 II, respectively. A P. pubiflorum x Uruguayan hybrid had 60 chromosomes that paired as 40.5 I + 9.7 II. The common genome in P. pubiflorum and dallisgrass is the J genome and there is only residual homology between th I genome and a second P. pubiflorum genome. Thus, P. pubiflorum is too distantly related to dallisgrass to use in the genetic enhancement of dallisgrass.