Inheritance and linkage study of isozyme loci and morphological traits in red clover
Information on inheritance of isozymes and linkage maps in Trifolium pratense L is limited. Genetic analysis of 18 isozyme systems and three morphological traits (white vs. pink flower, present vs. absent leaf marker and green vs. sun-red stem) was conducted. Six loci of four isozymes had simple Mendelian inheritance. Joint segregation analyses among 8 isozyme loci and 3 morphological gene markers (55 pair-wise combinations) resulted in the assignment of one linkage group. Two morphological markers coding for flower (c) and stem (gs) color were found to be in the same linkage group based on the analyses of two segregating families. The recombination values of the two progenies for c-gs were 0.079 and 0.113. No linkage was found between any of the isozyme loci and the morphological traits.
Red Clover Breeding and Genetics
Publisher Summary Red clover, Trifolium pratense L., has been a significant forage legume among agricultural crops. Red clover is adapted to a wide range of soil types, pH levels, and environmental conditions. This plasticity has enabled red clover to retain its usefulness for hay, silage, pasture, and soil improvement in much of the temperate region of the world. Red clover is a nitrogen-fixing legume, thus contributing to the supply of nitrogen available in the soil for subsequent crops. Red clover is a self-incompatible cross-pollinated species that, under natural conditions, produces very few self-seed. The mechanism of self-incompatibility is the one-locus, gametophytic S-allele system in which plants with the same S-alleles are prevented from selfing by slow growth of pollen tubes through styles. The system also prevents cross-fertilization of plants that have the same S-allele genotype. Details of the S-allele systems in red clover have been investigated by inbreeding via pseudo-self-compatibility (PSC).
Instrumentation and Automated Photometric Titration Procedure for Total Acidity Determination in Red Wine Employing a Multicommuted Flow System
An automated procedure for photometric titration of red wine and associated instrumentation is described. The procedure was based on the flow-batch approach implemented employing multicommutation. The photometric detection was carried out using a homemade LED-based photometer. The mixing device, LED, and photodetector were attached to the titration chamber in order to form a compact and small-sized unit. The flow system comprised an automatic injector and three-way solenoid valves, which were controlled by a microcomputer through an electronic interface card. The software, written in Quick BASIC 4.5, was designed with abilities to accomplish all steps of the titration procedure including data acquisition and real-time processing to decide about the course of titration in the following step and so forth, until the titration endpoint was reached. The usefulness of the proposed titration system was demonstrated by analyzing red wine samples. When results were compared with those obtained using the AOAC reference method, no significant difference was observed at the 95% confidence level. A relative standard deviation of ca  2% (n=9 ) was obtained when processing a typical red wine sample containing 7.3 gl -1 total acidity expressed as tartaric acid.