Der Einfluss der K-Konzentration der Nährlösung auf die Ertragsbildung,die Qualität und den K-Aufnahmeverlauf bei Hafer

Summary 1. In solution culture with oats (Avena sativa) the effect of the K concentration of the nutrient solution on yield and K uptake rates has been investigated. The K concentration of the different treatments were: 0.1, 0.3, 0.9 and 2.7 me K/l. These concentrations were kept constant during the whole growing period. 2. The growth of the plants in all treatments was normal. Even with the lowest K concentration no visible symptoms of K deficiency occurred. The highest grain yield was obtained with a K concentration of 0.9 me K/l. This yield was about 40% higher than the yield with the lowest K concentration and about 5% higher than the grain yield with the highest K concentration. 3. The increasing K supply had a favorable effect on the fat and crude protein content of the grains. The highest K concentration (2.7 me K/l) resulted in the highest content of crude protein (20%) and of fat (6.2%). 4. The rates of K uptake throughout the growing period differed considerably. The highest rates were measured during the shooting stage and the blossom stage. The K concentration of the nutrient solution influenced the uptake rates significantly. High yields were obtained if the K uptake at the beginning of the blossom stage was higher than 50% of the total K uptake. 5. The optimal K concentration for the yield performance, 0.9 me K/l, found in this experiment cannot be compared with K concentrations of the soil solution under field conditions without reservations. Under field conditions root growth and the contact surface between soil solution and root surface are different. Assuming that under field condition this contact surface nutrient solution/root surface is not larger than in solution culture, also a K concentration of 1 me K/l of the soil solution should meet the K demand of the plants, necessary for the production of high grain yields.      

Milling energy requirement of the aneuploid stocks of common wheat,including alien addition lines

Summary Aneuploid stocks, which included Triticum aestivum/alien, disomic, chromosome addition lines, wheat/alien, ditelosomic, chromosome addition lines, and the available aneuploids of Chinese Spring wheat, were used to locate genes that influence milling energy requirement (ME). Genes that affected ME were found on all seven homoeologous chromosome groups. The addition of complete wheat chromosomes 1B, 1D, 2A, 2D, 5B, 6B, 7B and 7D increased ME. Positive effects were also found in specific chromosome arms: 1BS, 2DS, 5AS, 5BS and 6BL. Wheat chromosome 3B conditioned low ME and the gene(s) responsible was located on the short arm. Other negative effects were attributed to wheat chromosome arms 4BL, 4DL, 5DS and 6DS. Alien chromosome additions that conferred high ME included 2H, 5H, 6H and 7H of barley, Hordeum vulgare and 2R, 2R, 4R, 4RL, 6R, 6RL and 7RL of rye, Secale cereale. Those that conferred a low ME included 1H ^ch of H. chilense, and 6u and 7u of Aegilops umbellulata, 5R and 5RS of S. cereale and 5R ^m and 5R ^mS of S. montanum. Although the control of ME is polygenic, there is a major effect of genes located on the short arms of homoeologous group 5 chromosomes.     

Extraction and genetic control of two new water-soluble proteins of mature barley seed

This paper describes the genetic control of two new water-soluble proteins in barley. Water-soluble proteins (WSPs) of mature barley seed form part of the albumin/globulin class of seed proteins. They can be extracted from hand-milled grain with water, though some WSPs are more efficiently extracted with a solution of 10 mM dithiothreitol. Polymorphisms for WSPs were detected in isoelectric focusing gels incorporating various ampholine combinations. Two new controlling genes (Wsp4 andWsp5) have been identified and located using wheat/barley chromosome addition lines and barley doubled haploids.Wsp4 is located on chromosome 2 (2H), andWsp5 was found to be tightly linked toWsp2 on the long arm of chromosome 7 (5HL). Segregation of a sixth gene (Wsp6) is also described, but this has not been mapped. The results are discussed with respect to other previously mappedWsp loci.This work was funed by the Scottish Office of Agriculture and Fisheries Department and the Agricultural and Food Research Council.     

Seed storage protein variation in Arachis species.

Seventy-two accessions, representing 22 species from sections Arachis, Erectoides, Extranervosae, and Triseminalae of the genus Arachis, were screened for seed storage protein polymorphism. Variation was detected between sections, between genome types, between species, and in some cases between different accessions of the same species or different seeds of the same accession. Arachis duranensis and one accession of A. cardenasii were found to have identical protein patterns. The greatest dissimilarity was found between species of the section Extranervosae and species of the section Triseminalae. Those of section Erectoides showed much similarity with some species of section Arachis. Protein polymorphism was shown to distinguish the two subspecies of A. hypogaea (fastigiata and hypogaea) in 27 of 28 cases. The seed protein profile of A. monticola was a combination of seed protein profiles from the two A. hypogaea subspecies. The relatedness between the various species was calculated and those that had the greatest similarity with A. hypogaea were A. spegazzinii and A. batizocoi.     

What is Microthrix parvicella ?

Microthrix parvicella is one of the filamentous bacteria that is known to create problems in the operation of activated sludge plants. Its physiology has already been investigated, although primarily in the context of its being a bulking species. It is now recognized that it is one of the major foam-forming organisms and, as such, needs further study. The initial isolation of M. parvicella did not prove to be as easy as would be expected from the earlier work and, eventually, micromanipulation was required. Growth studies showed that it exhibited several morphological forms, only one of which was that described previously. This has led to doubts about the classification of this species which does not yet have a clearly defined bacteriological designation.     

Letter from the Editors

Transgenic Research -