Abstract: A Tn-Mob element is provided comprising a transposon with a Mob-site inserted therein. Vectors and bacterial strains are provided containing the Tn-Mob element, as well as methods for its use. Such methods include the production of plasmid free bacterial strains.

Abstract: Vectors capable of replication in a broad host range of gram-negative bacteria are provided. The vectors are composite plasmids comprising a segment derived from an E. coli vector plasmid and a segment derived from a broad host range plasmid. The broad host range plasmid segment includes Mob-functions and DNA coding for replication functions with regions non-essential for broad host range replication or mobilizablity having been deleted. Bacterial strains containing the above plasmids as well as methods of cloning DNA employing such plasmids are also provided.

Abstract: A new method of combining the genetic mutants su.sub.1 and sh.sub.2 to produce sweet corn having an unusually high sugar content.

Abstract: Modified E. coli vectors are disclosed that are mobilizable to a wide range of gram-negative bacteria, but are not self-transmissible. The modified E. coli plasmids replicate only in bacterial strains of the E. coli group. Mobilizer strains of E. coli are also provided, as well as methods for employing the modified E. coli vectors for transposon mutagenesis, site-specific gene transfer, and the construction of DNA libraries.

Abstract: Most of the corn in the United States is grown from hybrid seed. The production of hybrid seeds necessitates the emasculation of the desired female parent plant. If this emasculation is carried out by hand, then it becomes a major cost factor. One method to overcome these costs is to obtain inbred lines of corn which have stable cytoplasmic male sterility. Such cytoplasmic male sterility should remain stable when the genome of the inbred line is replaced by the genomes of other inbred lines by backcrossing.Three major groups of cytoplasmic male sterility (C, T and S) have been extensively studied. In the past the cms S-type has not been extensively utilized in the production of hybrid corn seed because cms S-cytoplasms do not show stable male sterility and also in some backgrounds have a high rate of genetic reversion to male fertility. We describe here the production of a novel stable cytoplasmic male sterile strain (LBN) which remains stably sterile in combination with a large number of inbred corn lines.

Abstract: The novel compounds Iodo-p-hydroxyphenyl-glycylglycylglycine and Benzoylprolylphenylalanylarginine are disclosed, together with radioisotope labeled forms thereof, wherein the radioisotope is incorporated in the Iodo-p-hydroxyphenyl moiety or the Benzoyl moiety, respectively. These compounds are useful as substrates for angiotensin converting enzyme in an assay for that enzyme's activity.

Abstract: A new cultiver of Naval Orange plant is characterized by its very late maturation and very late hanging.