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The genus Salix (willow) contains a number of species of great value as biomass crops. Efforts to breed varieties with improved biomass yields and resistances to pests and diseases are limited by the lack of knowledge on the genetic basis of the traits. We have used AFLP and microsatellite markers to construct a genetic map of willow from a full-sib cross of the diploid species Salix viminalis (2n = 38). In accordance with a double pseudo-testcross approach, separate parental maps were constructed and merged to produce a consensus map comprising 291 AFLP and 39 willow microsatellite markers. Nineteen poplar microsatellites were also tested in willow. Five of these amplified loci, of which two were mapped. Linkage groups of the consensus map that could be identified in the parental maps are presented here and spanned 1,256.5 cM with an average interval between markers of 4.4 cM.

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Five primer pairs were developed that amplify microsatellite loci in three agronomically important Echinochloa (L.) Beauv. species: E. colona (L.) Link, E. crus‐galli (L.) Beauv. and E. crus‐pavonis (Kunth) Schultes. The microsatellites were tested on 24 individuals representing three species collected in rice fields from different geographical regions and revealed 3–7 alleles per microsatellite. Gene diversity [1 − Σpij2] for four polymorphic loci within E. crus‐galli ranged from 0.12 to 0.61. Alleles at a fifth locus were useful in discriminating the species. The microsatellites should provide useful markers for intraspecific diversity studies and aid classification of species within this complex genus.

AFLP and SSR DNA markers were used to construct a linkage map in the coconut (Cocos nucifera L.; 2n = 32) type Rennell Island Tall (RIT). A total of 227 markers were arranged into 16 linkage groups. The total genome length corresponded to 1971 cM for the RIT map, with 5-23 markers per linkage group. QTL analysis for yield characters in two consecutive sampling periods identified nine loci. Three and two QTLs were detected for number of bunches and one and three QTLs for number of nuts. The correlation of trait values between characters and evaluation periods is partially reflected in identical QTLs. The QTLs represent characters that are important in coconut breeding. The cosegregation of markers with these QTLs provides an opportunity for marker-assisted selection in coconut breeding programmes.

Variation at three microsatellite loci was investigated in five populations of sea beet on the Dorset coast. Genetic variation among the populations was estimated using two different methods. Estimates of F ST were obtained using the program FSTAT, and estimates of R ST were obtained using the program AMOVA. These different estimates of genetic distance were used to test for isolation by distance with partial matrix correspondence tests and were compared with patterns of variation in F ST estimates from isozymes and single-copy nuclear restriction fragment length polymorphisms (RFLPs). F ST from isozymes, F ST from RFLPs and R ST from microsatellites all showed evidence of isolation by distance, whereas F ST from microsatellites showed strong similarities within populations that were not related to distance. These results suggest that, compared with isozymes and RFLPs, mutation rates at microsatellite loci are high in these populations. They also suggest that stepwise mutation processes are occurring at these loci. The data provide valuable evidence that all three types of marker can detect similar patterns of population structure. The results are discussed with respect to estimates of genetic distance at microsatellite loci in human populations.