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The composition of pollenkitt and its role in the progamic phase of reproduction are poorly understood. With the aim of extending knowledge on these topics, we chose to study two monocotyledons rich in pollenkitt, with bi-celled and long-lived pollen and dry-type stigma: Crocus vernus Hill subsp. vernus and Narcissus poeticus L. Fatty acids of pollenkitt were assayed with gas chromatography. Germination tests were performed in vivo by pollinating the stigmas with a beard hair under a stereomicroscope, and in vitro in liquid culture medium using pollen, either treated or not, with carbon disulphide to remove pollenkitt. The pollen tube percentages were evaluated using fluorescence microscopy techniques. Scanning electron microscopy was used to examine pollen and to follow the early post-pollination stages. Pollenkitt forms bridges between pollen grains but not between grains and stigma papillae. It consists of a mixture of 25 fatty acids, most with long and unsaturated chains, among which are some omega acids. The same acids with different percentages persist on the peritapetal membrane. After its removal, the pollen loses adhesiveness and dries quickly, but retains full capacity for germination on the papillae and can even trigger germination in contiguous pollen grains that do not touch the papillae. The results, while confirming the key role of pollenkitt in protecting pollen and favouring pollination, suggest secondary roles in the progamic phase, and highlight the interactive ability of the pollen regardless of lipid shell. The predominance of fatty acids with 18:3 and 16:0, as already noted in Brassica napus pollenkitt, suggests their hierarchy independent of plant species., (© 2019 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.)

Introduction: Galanthamine is a benzazepine alkaloid used as a drug to relieve symptoms of Alzheimer's disease. For pharmaceutical use this natural product has been extracted from the plant Leucojum aestivum (Amaryllidaceae) or produced synthetically. Limited supply of the natural source and high cost of synthetic production has led to a search for alternative sources of galanthamine. The bulbs of Narcissus pseudonarcissus (Amaryllidaceae) have been identified as a potential source of raw material for galanthamine extraction. Since inconsistent chemical composition can be an issue with medicinal plant material, it is of interest to know whether large variations occur between Narcissus bulbs grown in different geographical locations., Objective: To evaluate whether large differences exist in the overall metabolic profiles of Narcissus bulbs grown in the two most important cultivation regions., Methodology: (1)H NMR and principal component analysis were used for an unbiased comparison of the bulb samples., Results: Overall metabolite profiles were quite similar, but galanthamine levels could slightly discriminate samples by geographical region. (1)H NMR was used for quantitation of galanthamine, and was found to be comparable to quantitation by HPLC. Compared with conventional chromatographic methods, sample preparation for (1)H NMR analysis is simple and rapid, and only a small amount of plant material is required., Conclusions: Since useful qualitative and quantitative information about the metabolic state of Narcissus bulbs can be obtained by (1)H NMR, this method is useful for agricultural applications, and for quality control of raw material used in the pharmaceutical industry., ((c) 2009 John Wiley & Sons, Ltd.)