suns. The extension of the Andromeda nebula beyond the photographic limits is presumably typical of what may be found for other such objects. Comparisons with the surface brightness of the galaxy are still hampered by uncertainties in the data for our own system. There may be no part of the galaxy which, seen from outside, would be as bright as the central portion of M 31. In the latter system ...

Intergenomic translocations between wheat, Hordeum chilense and Hordeum vulgare have been obtained in tritordeum background. Advanced lines from the crosses between three disomic chromosome addition lines for chromosome 2Hv, 3Hv, and 4Hv of barley (Hordeum vulgare) in Triticum aestivum cv. Chinese Spring (CS) and hexaploid tritordeum (2n = 6x = 42, AABBHchHch) were analyzed. Multicolor FISH usi...

Polyploidization is a major mechanism of speciation in plants. Within the barley genus Hordeum, approximately half of the taxa are polyploids. While for diploid species a good hypothesis of phylogenetic relationships exists, there is little information available for the polyploids (4×, 6×) of Hordeum. Relationships among all 33 diploid and polyploid Hordeum species were analyzed with the low-co...

The origin of naked barley (Hordeum vulgare L.

The Columbia root-knot nematode, Meloidogyne chitwoodi race 2, is associated with several plant species, including members of the tribe Triticeae. We evaluated 15 diploid species for M. chitwoodi gall and reproductive indices from the following genera: Agropyron, Pseudoroegneria, Hordeum, Psathyrostachys, and Thinopyrum. Species from the genus Thinopyrum (Thinopyrum bessarabicum; J genome) and ...

Likelihood methods are developed for the estimation and testing of multiple-locus gametic disequilibria, using log-linear models of parametric effects. The estimates of disquilibrium are related to Kimura's Z-measure, and may be extended to multiple alleles and multiple loci. Likelihood ratio test criteria are constructed, which are asymptotically distributed as chi(2). The analysis is partitio...