Recognition of Bromus Richardsonii and B. Ciliatus: Evidence from Morphology, Cytology, and DNA Fingerprinting (Poaceae: Bromeae)

Sin ce our goa l was to dete rm ine character istic difference s betwee n Brom us richardsonii a nd B. cilia /us. a d iscr iminate analysis (DA), princ ipal components ana lysis (PC A), mult idimen s ional sca ling (M DS) , bivar iate ana lysis , and an amplified fragm ent len gth polym orphism s (AFL P) ana lys is were und ert ake n o n 93 herbar ium speci mens and 31 field-coll ec ted popul ation s. A cytologi ca l survey of B. cili a tus. B. richa rdsonii , a nd B. mu croglumis confirm previous rep ort s that the first spec ies is dipl oid (2n = 14) and the latter two are tetrapl oid (2 n = 28). All tax a we re co rrec tly c lassi fied in the DA and impo rta nt charac ters fo r each of the species were identified. Bromus rich ardson ii has lemmas with sca ttered hair s on the low er half between the mid nerve and margins [glabrous in B. cilia/US], anthers (1.2) 1.6-2.7 (3.4) mm lon g [(0.9) 1-1.4 (1.6) mm long in B. cilia/us], second glumes (7.8) 8.9-11.3 (13.2) mm lon g [(6.2) 7.1-8.5 (9.5) in B. cilia /us); and basal sheaths with den se, short to medium hairs [gl abr ou s or with lon g hairs in B. cilia /us]. The PCA easily separated B. cilia/US and B. richa rd-sonii into two we ll-de fined groups and MDS mirrored the principal components analysis but displ ayed mor e ove rlap of indivi dua ls between the two groups. The AFLP-derived UPGMA dendrogram se pa-rated 154 ind ividua ls into two d istinct c lusters, one consisting entirely of B. cilia/us individuals and the other co ns isting of B. richa rdso n ii individuals with six individuals of B. mucroglumis embedded within. Our study c lear ly ind icates that there are distinctive morphological, cytological , and ge netic differen ces to distin gui sh B. richa rdso nii and B. ciliarus as separate species. la parte baja entre el nervio medio y las mill-genes [glabra en B. cilia/us ].5) en B. ciliatusi ; y vaina basal con pelo den so , corto a medio [glabra 0 con pelo s largos en B. cilia/us). EI PCA separ6 facilrnente a B. cilia/us …