Detection of Pollen Germination Inhibitors in Brassica oleracea Tissue Extracts

Petunia hybrida and Lilium lankongense pollens were germinatedon thin layer chromatography (TLC) plates following chromatographyof extracts from the self-, cross- and unpollinated stigmas,styles and ovaries and the seeds, leaves and pollen of threeinbred Brassica oleracea families. Zones of pollen germinationinhibition on the TLC plates showed that inhibitory compoundswere present in the tissue extracts. The R_f values and numberof these compounds varied with the tissue used, stigma tissuecontaining the largest amounts and the greatest number of inhibitors.In contrast, differences between the inbred lines tested wereslight and quantitative. Pollen from both P. hybrida and L.lankongense gave the same results; that from B. oleracea couldnot be used because of its poor germination. Brassica oleracea, Brussels sprout, kale, Lilium lankongense, Petunia hybrida, pollen germination, thin layer chromatography, germination inhibitors, phytoalexin, bioassay     

Genetically determined variation in seed germination and field emergence of Brassica oleracea

The germination and field emergence levels and germination rates were measured of Brassica oleracea seed lots obtained by outcrossing the progenies of two half diallels to a single pollen parent. Analysis of variation of the seed lots classified according to their maternal grandparents showed that both general and specific combining abilities were important in accounting for the observed differences; the observed performance of many of the seed lots was satisfactorily accounted for by their grandmaternal parentage. The capacity to give high levels of germination was not necessarily related to the capacity to give high relative field emergence levels, maternal grandparents apparently differing in their ability to contribute to these two characters.     

The Effect of Brassica oleracea Stigma Extracts on the Germination of B. oleracea Pollen in a Thin Layer Chromatographic Bioassay

Hodgkin, T. and Lyon, G. D 1986. The effect of Brassica oleraceastigma extracts on the germination of B. oleracea pollen ina thin layer chromatographic bioassay.—J. exp. Bot. 37:406–411. A procedure for germinating Brassica oleracea pollen on thinlayer chromatography plates pretreated with 20 mol m^–3tris(hydroxymethyl) methyl-aminopropanesulphonic acid (TAPS)buffer, pH 8·0 has been devised and used to detect pollengermination inhibitors in B. oleracea stigma extracts. Inhibitory zones in extracts of stigmas, unpollinated, or collected0·5, 4, 8 and 24 h after self- or cross-pollination,differed little in R_F values and sizes. Extracts of stigmascollected 1 h and 2 h after self-pollination gave a small additionalinhibitory zone which was not detected in 1 h and 2 h cross-pollinatedstigma extracts. The results showed some differences from thoseobtained using Petunia hybrida pollen germinated on T.L.C. platesthat were not pretreated with buffer. The nature of the differencesbetween the two bioassays is discussed and some possible reasonsfor them indicated. Key words: Pollen, germination inhibitors, self-incompatibility, Brassica oleracea