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.
Identification of tomato cultivars (Lycopersicon esculentum) by polyacrylamide isoelectric focusing
SummaryIsozyme analyses have been used for the definitive identification of many plant cultivars, but not for cultivated tomatoes. Six isozyme systems, namely alcohol dehydrogenase, acid phosphatase, phosphoglucomutase, esterase, phosphoglucoisomerase and 6-phosphogluconate dehydrogenase of tomato seed extracts were resolved by isoelectric focusing on polyacrylamide gels with a narrow pH gradient. Nine alcohol dehydrogenase phenotypes were distinguished which, with three acid phosphatase phenotypes, identified twelve of the seventeen cultivars. Fewer differences were found for the other isozymes. Since this method could differentiate between breeding parents and their progeny it is concluded that further investigations are warranted.
Red clover--an interesting species for genecological studies.
Fifty years ago Turesson published the first fundamental papers from his studies about genecology. Genecology has been of great importance in understanding the results of natural selection and the origin of local varieties. In red clover (Trifolium pratense L.) many local varieties have arisen and have been carefully studied. Some Swedish experiments with such varieties are described and discussed. Special studies have been made to elucidate the effects of natural selection in red clover. Among factors which have a strong selective effect under Swedish conditions daylength seems to be especially important.