An efficient method to separate tetraploid from diploid plants after colchicine treatment of turnips (Brassica campestris var. rapa)

Abstract

To obtain a Cl-population with a high percentage of tetraploids after colchicine treatment of turnips, a selection in the C o can be used. A comparison is made between two criteria for this selection, viz. the average pollen grain size and the variation in pollen grain size.C0-selection on the basis of the average pollen grain size of five pollen grains per plant reduced the number of diploids in the C1 considerably. When the variation in pollen grain size of these five pollen grains is included as a selection-criterion the number of tetraploids in the C~ increased.The two methods are discussed in the light of the working efficiency and the genetical variation in the tetraploid C~-population. It is concluded that the character of the initial material should govern the choice of the selection criterion.

The ploidy of plants obtained from anther culture of cauliflowers (Brassica oleracea var. botrytis)

“…It is not known why some species give mostly haploids from anther culture, whereas others give a majority of diploids or polyploids. In Datura innoxia, younger (uninucleate) microspore stages gave mostly haploids while pollen at later stages of development (binucleate) gave mostly non-haploids (Sunderland, Collins & Dunwell, 1974). The oldest pollen stage gave mostly triploids, with one tetraploid and one hexaploid plant.…”

“…One leaf was taken from each plant, and 15 guard cells were measured for each leaf, and the mean taken as the estimate for the plant. Pollen grain size was measured in the same way, with the pollen mounted in cotton blue in lactophenol (Speckmann, Dijkstra & Ten Kate, 1967). Fifteen pollen grains were measured at random for each sample, but care was taken to exclude infertile grains.…”

Poliploidização em berinjela (Solanum melongena L.): II - Observações em plantas resultantes de tratamentos com colquicina

“…O critério a ser adotado depende do material, do méto-do de tratamento empregado e das possibilidades pessoais de realização das observações (4,6,15,18) . No caso presente a seleção baseou-se no aspecto morfológico das plantas, sendo que numa parte destas fez-se também a análise do pólen e do número de cromossomos.…”

Resynthetisierter Raps als Modell zur Untersuchung der fixierten Heterosis bei allopolyploiden Pflanzen

“…Eine höhere Ploidiestufe führt bei Pflanzen in den meisten Fällen zu größeren Zellen, dickeren und breiteren Blättern und größeren Blüten (GOTTSCHALK 1976). Einige morphologische Eigenschaften wie die Pollengröße (SPECKMANN et al 1967) 1976), wobei auch Untersuchungen, die sich mit den selben Arten beschäftigen, zu sehr unterschiedlichen Ergebnissen kommen. Auch in der Gattung Brassica wurde so neben einer höheren auch eine geringere Biomasseproduktion von tetraploiden gegenüber ihren diploiden Ausgangspflanzen gefunden.…”