Gene transfer in crop improvement.

Transfer of genes between plant species has played an important role in crop improvement for many decades. Useful traits such as resistance to disease, insects, and stress have been transferred to crop varieties from noncultivated plants. Recombinant DNA methods greatly extend (even outside the plant kingdom) the sources from which genetic information can be obtained for crop improvement.

Allozyme variation and evolutionary relationships of grain amaranths (Amaranthus spp.).

Allozyme studies in amaranth provided useful assays of genetic variation in order to verify the patterns inferred from morphological traits, for elucidating the genetic structure of landraces, and for the studies of evolutionary relationships among wild, weedy and crop species. Thirty-four populations of cultivated New World amaranths were surveyed along with 21 weedy New World populations for allozyme variation at nine electrophoretic enzyme loci. Eleven populations of cultivated amaranths from the Indian State of Uttar Pradesh and six from Nepal were also surveyed for a comparison.

Biosystematics and agronomic potential of some weedy and cultivated amaranths.

Three weedy amaranths (Amarantkus hybridus, A. retroflexus and A. powellii) from nine California sites, three domesticated species (A.