Dutch Variety Research Articles

Three-way cluster and component analysis of maize variety trials

Data from the Dutch Variety List Trials for maize were analysed with three-way mixture method clustering and three-mode component analysis. The main objective of the paper is to demonstrate the usefulness of such multivariate analysis techniques for plant breeding data. In particular, attention is paid how one may gain insight into the complex patterns that are embodied in this type of data sets.

Analysing genotype by environment interaction in Dutch potato variety trials using factorial regression

Genotype by environment interaction was investigated for yield data from the official Dutch Variety List trials for potato. The data set included 64 genotypes by 26 environments, where environments consisted of year by soil type combinations. Factorial regression models incorporating genotypic and environmental covariates in the interaction were used to analyse the data. The merits of factorial regression models were compared with those of biadditive models. Factorial regression models and biadditive models described comparable amounts of interaction, but factorial regression models provided a better basis for biological interpretation of the interaction.

Improvement of caraway essential oil and carvone production in The Netherlands

The caraway fruit ( Carum carvi L.), usually referred to as seed, has an aromatic fresh taste and smell caused by an essential oil contained in ducts in the pericarp (2–7% of air-dry fruit weight). The oil consists mainly of the two monoterpenes s-(+)-carvone and s-(+)-limonene in approximately equal amounts. The carvone dominates the olfactory characteristic of caraway, and has been shown to be biologically active in inhibiting sprouting of tubers (potatoes), germination of seeds, and growth of certain fungi. A national R and D programme was started in 1990 with the aim of improving caraway essential oil and carvone production. This included strengthening the ongoing CPRO-DLO breeding research effort to maximise essential oil and carvone production potential. Carvone content in 2–5 g whole seed samples is reliably recorded by Near Infra-Red spectroscopy (NIR). Two generations of recurrent mass selection for high carvone content yielded a population 20% higher in content. The first Dutch variety of annual or spring caraway performed well in the past three years and is in the last year of variety registration research. Furthermore, plant physiological research was started to elucidate the relationships between carbohydrate availability and seed and essential oil production.

Notes and news

Notes and news PAUL SCHUITEMA t With the death of Paul Schuitema (27 February i8g?-25 October 1973), one of the pioneers of the new functional typography of the twenties and thirties has passed away. Together with Piet Zwart, who taught in Rotterdam, and Gerrit Kiljan, who was his colleague at the academy in The Hague, Schuitema developed, both as a practising typographer and as a teacher, the specifically Dutch variety of that international style which was directly linked with the general concepts of design of Neue Sachlichkeit, functionalism, the Bauhaus and the De Stijl movement - neglecting, for present purposes,

Frequencies of genetical factors determining male sterility in onion (Allium cepa L.) and their significance for the breeding of hybrids

In selections of some more or less commonly grown onion varieties in the Netherlands the frequencies of genetical factors governing male sterility were determined. In the leading Dutch variety Rijnsburger the chromosomal factor ms was found to occur in a frequency of over 0.95 and the cytoplasmic factor S in a frequency of less than 0.01.

Heterosis and combining ability in hybrids ofAvena sativaL. andA. byzantinaC. Koch.

SUMMARYThree varieties ofAvena byzantinaC. Koch., Sierra, Avon and Anita, originating respectively in California, Australia and South Africa, together with the Dutch variety Condor (A. sativaL.) were used as ‘subject’ varieties in crosses with a range of nine tester varieties of mainly north-west European origin. The results of a yield trial of spacedF1transplants and a drilledF2trial are presented.In theF1trial there was marked heterosis for grain yield, the thirty-six crosses yielding, on average, 109 % of the higher yielding parent, with individual cross values ranging from 68 to 139%. Heterosis was more marked insativa × byzantinacrosses than insativa × sativacrosses and the variety Sierra showed particularly high general combining ability. In theF2trial, heterosis was considerably reduced and the thirty-six crosses yielded, on average, only 96% of the higher yielding parent. In someF1crosses, heterosis for grain yield was accompanied by transgression of the higher yielding parent in number of panicles per unit area. The number of grains per panicle was positively correlated with grain yield in theF2trial but no heterosis was observed for this component. Grain size was negatively correlated with yield in theF2trial and heterosis for this component was observed in a few crosses in which yield heterosis occurred.Straw height was positively correlated with grain yield in theF1trial but negatively correlated in theF2trial. Crosses showing heterosis for yield exceeded the mid-parent but not the taller parent in straw height. The ratio of grain yield to straw yield was higher for the progenies of thebyzantinavarieties Sierra and Avon than for the progenies of thesativasubject Condor. Grain yield was positively correlated with number of days to 50% panicle emergence in both trials.It is concluded that theA. byzantinavarieties Sierra and Avon could, with advantage, be used for hybridization with adapted genotypes ofA. sativa, thereby enlarging the gene pool available to oat breeders in north-west Europe.

Variedades de batatinha (Solanum tuberosum L.) procedentes da Polônia

As variedades de batatinha Dar, Oka, Bem, Pionier e Kolobrzeskie, foram recebidas da Polônia, para verificação do seu comportamento sob as nossas condições, em confronto com a variedade "Eigenheimer", já conhecida (1). Com êsse objetivo, foram instaladas oito experiências, sendo três em Capão Bonito, em solo sílico-argiloso, três em Louveira, em salmourão, e duas em Indaiatuba, em terreno sílico-argiloso. Das observações realizadas durante o período vegetativo, e dos resultados da produção, conclui-se o seguinte : a) tôdas as variedades apresentaram película amarelada e que se tornou verde à ação da luz ; b) a folhagem da variedade Kolobrzeskie se mostrou de um verde-claro e de porte médio, contrastando com a Pionier, que se mostrou de um verde forte e porte avantajado ; c) a Kolobrzeskie e a Pionier revelaram boa resistência à Phytophthora injestans e Alternaria solani, principalmente quando comparadas à "Eigenheimer", ao passo que a Oka mostrou ser pouco resistente ; d) a variedade Bem se mostrou mais suscetível às manchas internas de orígem fisiológica (chocolate), sendo que a Pionier revelou pequena tendência a êsse defeito ; e) as variedades mais produtivas foram, por ordem decrescente (média de 6 experiências) : "Eigenheimer" Oka, Kolobrzeskie, Bem, Pionier e Dar; f) as maiores percentagens de tubérculos graúdos foram fornecidas pela Kolobrzeskie e Bem, e, de refugo, pelas variedades Oka, Dar e "Eigenheimer".