Two pathways of 2n gamete formation and differences in the frequencies of 2n gametes between wild species and interspecific hybrids.

Epidendrum produces 2n gametes with high frequency. This paper is the first to report on multiple pathways for forming 2n gametes, meiotic defeats, and pre-meiotic chromosome doubling. Unreduced 2n reproductive cells are predominantly involved in pathways that lead to polyploid plants.

Induction of adventitious shoots and tetraploids in L. by treatment of antimitotic agents in vitro without plant growth regulators.

We examined the effects of five antimitotic agents using L. 'Maryland True Pink' on the induction of adventitious shoots resulted in increase of frequencies of chromosome doubling without plant growth regulators. Seeds were treated in vitro with 0, 16.

N(2)O induces mitotic polyploidization in anther somatic cells and restores fertility in sterile interspecific hybrid lilies.

Fertile plants undergoing male gametogenesis can be treated with nitrous oxide (N(2)O) gas to obtain 2n male gametes. N(2)O treatment is also expected to restore the fertility of interspecific hybrids through meiotic restitution or mitotic amphidiploidization. However, this technique has few applications to date, and it is un-known how N(2)O treatment restores fertility in sterile hybrids.

Shifts in mycorrhizal fungi during the evolution of autotrophy to mycoheterotrophy in Cymbidium (Orchidaceae).

Premise Of The Study: Mycoheterotrophic plants, which completely depend upon mycorrhizal fungi for their nutrient supply, have unusual associations with fungal partners. The processes involved in shifts in fungal associations during cladogenesis of plant partners from autotrophy to mycoheterotrophy have not been demonstrated using a robust phylogenetic framework.

Methods: Consequences of a mycorrhizal shift were examined in Cymbidium (Orchidaceae) using achlorophyllous and sister chlorophyllous species.

The evolutionary history of mycorrhizal specificity among lady's slipper orchids.

Although coevolution is acknowledged to occur in nature, coevolutionary patterns in symbioses not involving species-to-species relationships are poorly understood. Mycorrhizal plants are thought to be too generalist to coevolve with their symbiotic fungi; yet some plants, including some orchids, exhibit strikingly narrow mycorrhizal specificity. Here, we assess the evolutionary history of mycorrhizal specificity in the lady's slipper orchid genus, Cypripedium.

In vitro asymbiotic germination of immature seed and formation of protocorm by Cephalanthera falcata (Orchidaceae).

Background And Aims: Many Orchidaceous species are threatened globally by development and over-collection from their natural habitats for horticultural purposes. Artificial propagation from seeds is difficult in most terrestrial orchids native to temperate regions. Seed production is another limiting factor in the artificial propagation for these species because of the lessened probability of pollination and the destruction of fruit by insect larvae.

Diacylated 8-C-glucosylcyanidin 3-glucoside from the flowers of Tricyrtis formosana.

A new diacylated 8-C-glucosylanthocyanin was isolated from the purple flowers of Tricyrtis formosana 'Fujimusume' as one of the major anthocyanins along with four known pigments. The structure of this pigment was determined to be 8-C-(6-O-trans-sinapoyl)-beta-glucopyranosylcyanidin 3-O-(6-O-malonyl-beta-glucopyranoside) by chemical and spectroscopic methods. In addition, four known pigments, 8-C-glucosylcyanidin 3-malonylglucoside, cyanidin 3-glucoside, cyanidin 3-rutinoside and cyanidin 3-malonylglucoside, were identified as the major anthocyanins in the flowers.