Evolution in Spartina (Gramineae): II. Chromosomes, basic relationships and the problem of S. ×townsendii agg.

摘要: An intensive study of the cytology and sexual behaviour classical Spartina x townsendii agg. their putative parents in southern England reveals a more complex chromosomal situation than had previously been reported, including aneusomaty Southampton S. alterniflora populations Chromosome numbers are 2n= 60 62 for maritima respectively 120, 122 124 (chromosome races) F1 Amphidiploid derivatives respectively. These numbers, though summation is less precise hitherto still support hybridity amphidiploid origin process further confirmed by meiotic pairing data discovery wild backcross hybrids (2n= c.90and 2n=76) near site at Southampton. The chromosome number alterniflora, out line with x= 10 base genus, explained as polysomic condition 60+ 2) needs investigation North American populations. It suggested that races found will provide adaptive variation this highly significant successful amphidiploid.