Effects of Alien Chromosome Additions on Photosynthesis in Wheat

Abstract

We assessed the effects of rye (Secale cereale), two species of Hordeum, and Thinopyrum bessarabicum chromosome additions on some photosynthetic attributes in the background of hexaploid wheat, Triticum aestivum. Photosynthetic rates per unit leaf area (PN) Of both ``Imperial{''} and ``Blanco{''} rye were higher than that of ``Chinese Spring{''} (CS). When compared to CS, addition of chromosome 3R of ``Imperial{''} rye to CS reduced chlorophyll content per unit leaf area (Chl) and, increased P,v and chlorophyll a/b ratio. Addition of chromosome 3R of ``Blanco{''} rye to CS also increased chlorophyll a/b ratio. In the background of ``FEC 28{''}, addition of chromosome 4R of ``Seigle{''} rye decreased both PN and Chl. Photosynthetic rate of ``Seigle{''} rye was lower than that of ``FEC 28{''}. In the background of ``Grana{''}, disomic addition of ``Dankowskie Zlote{''} rye chromosomes did not modify PN, although ``Dankowskie Zlote{''} rye showed higher values than ``Grana{''}. For wheat-barley disomic addition lines, chromosome 7H of barley (Hordeum vulgare cv. Betzes) increased PN in the background of CS. The addition of chromosomes 4H and 7H also increased Chl. H. chilense (H-ch H-ch) showed lower PN values than CS. The addition of the alpha -arm of chromosomes 2H(ch) and 6H(ch) also resulted in lower PN values than CS. In the case of CS-Thinopyrum bessarabicum ((EEb)-E-b) addition lines, the addition of chromosomes 2E(b) and 5E(b) resulted in lower P-N values than that of CS. The results generally suggested that photosynthetic rates were dependent upon the combination of the individual added chromosome and the recipient genotype of hexaploid wheat.