A comparison of RAPD and isozyme analyses for determining the genetic relationships among Avena sterilis L. accessions.

Isozyme analysis is a valuable tool for determining genetic relationships among breeding lines and populations. The recently developed DNA technologies which can assay a greater proportion of the plant genome are providing a plentiful array of additional genomic markers. The objective of this research was to compare random amplified polymorphic DNA (RAPD) versus isozyme-based estimation of relationships among 24 accessions of a hexaploid wild oat, Avena sterilis L.

Genetic variation for quantitative traits in soybean lines derived from tissue culture.

Tissue culture may generate useful genetic variation for quantitative traits. The objective of this study was to analyze genetic variation for ten quantitative traits of soybean [Glycine max (L.) Merr.

Mapping maize microsatellites and polymerase chain reaction confirmation of the targeted repeats using a CT primer.

Microsatellites, also called simple sequence repeats (SSRs), have yielded an important class of DNA markers most notable for mapping mammalian genomes. To study the occurrence of microsatellites and their inheritance in maize, a search was made of 280 maize GenBank sequences. Six SSRs were chosen and unique flanking primers were designed for polymerase chain reaction (PCR) amplification.

Culturing peanut (Arachis hypogaea L.) zygotic embryos for transformation via microprojectile bombardement.

A method for rapidly producing fertile peanut (Arachis hypogaea L.) plants from embryo axes was developed for use with microprojectile bombardment. Using this method, the apical meristem housing the germ line cells was easily exposed for bombardment without compromising the viability of the plant.

Anther culture as a probable source of resistance to tobacco black shank caused by Phytophthora parasitica var 'nicotianae'.

Anther-derived doubled haploid (ADH) tobacco lines possessing a high level of resistance to tobacco black shank, Phytophthora parasitica (Dast.) var 'nicotianae' (B. de Haan) Tucker (Ppn), have been identified from a cross of two tobacco cultivars susceptible to this disease.

The value of gametoclonal variation in breeding for quantitative traits in flue-cured tobacco (Nicotiana tabacum L.).

In tobacco (Nicotiana tabacum L.), anther-derived doubled haploid populations have been shown to exhibit large amounts of unexpected genetic variation and a severe depression in cured leaf yield when compared to conventionally inbred genotypes from comparable sources. A previous study had predicted that the yield depression observed in a doubled haploid population-derived from a near homozygous cultivar, NC95, might be overcome through a recurrent selection program.

Phosphorus stress effects on assimilation of nitrate.

An experiment was conducted to investigate alterations in uptake and assimilation of NO(3) (-) by phosphorus-stressed plants. Young tobacco plants (Nicotiana tabacum [L.], cv NC 2326) growing in solution culture were deprived of an external phosphorus (P) supply for 12 days.

Factor and principal component analyses as alternatives to index selection.

Selections from factor and principal component analyses were compared with those from the Smith-Hazel index when selecting for several switchgrass (Panicum virgatum L.) traits. The objective of this study was to examine several alternatives to index selection.

A mitochondrial protein associated with cytoplasmic male sterility in the T cytoplasm of maize.

Mitochondrial DNA in the T male-sterile cytoplasm (cms-T) of maize contains an open reading frame (ORF 13) associated with the T type of sterility. Antibodies raised to a chemically synthesized oligopeptide corresponding to ORF 13 were used to establish the expression of a 13-kDa protein from this reading frame. The 13-kDa polypeptide is synthesized uniquely in cms-T maize and purifies with the membrane fraction of T mitochondria.